Researchers Say The Aliens Are Silent Because They Are Extinct (theconversation.com)

HughPickens.com writes: The Conversation reports that according to research by Dr. Charles Lineweaver and Dr. Aditya Chopra, a plausible solution to Fermi's paradox is near universal early extinction of life on exoplanets, which they have named the Gaian Bottleneck. "The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens," says Chopra. "The mystery of why we haven't yet found signs of aliens may have less to do with the likelihood of the origin of life or intelligence and have more to do with the rarity of the rapid emergence of biological regulation of feedback cycles on planetary surfaces." According to the researchers, most early planetary environments are unstable. To produce a habitable planet, life forms need to regulate greenhouse gases such as water and carbon dioxide to keep surface temperatures stable. About four billion years ago, Earth, Venus and Mars may have all been habitable. However, a billion years or so after formation, Venus turned into a hothouse and Mars froze into an icebox. Even if wet rocky Earth-like planets are in the "Goldilocks Zone" of their host stars, it seems that runaway freezing or heating may be their default fate. Large impactors and huge variation in the amounts of water and greenhouse gases can also induce positive feedback cycles that push planets away from habitable conditions. The difference on Earth may be that as soon as life became widespread on our planet, the earliest metabolisms began to modulate the greenhouse gas composition of the atmosphere. "The emergence of life's ability to regulate initially non-biological feedback mechanisms could be the most significant factor responsible for life's persistence on Earth, conclude Lineweaver and Chopra. "Even if life does emerge on a planet, it rarely evolves quickly enough to regulate greenhouse gases, and thereby keep surface temperatures compatible with liquid water and habitability."

Comments

It's a f...

[AchilleTalon]

It's a fucking good reason to be silent, I admit.

Re:It's a f...

[inode_buddha]

.... tasted pretty good, too.

Re:It's a f...

[Rei]

Except that it ignores subsurface oceans, which seem to be quite stable over long timeperiods and quite likely to be very abundant in the universe.

Sure, a species evolved to an undersea environment faces challenges in getting to their surface and beyond... but if we can get out of this deep gravity well after such a (geologically) short period of time after our species' evolution, sentient species in subsurface oceans with hundreds of millions or billion years on their "hands" would surely deal with the technical difficulties.

And of course there's also the possibility of LNAWKI, but let's just stick with LAWKI for now.

My personal suspicion is that a wide variety of factors work together to keep complex life rather rare on a per-planet basis, great distances dilute any signals from any that do achieve sentience, and the speed of light and difficulty of propagating a civilization outward at near that limit keeps the vast majority far away. Basically, rarity + dilution. But that's just my suspicion.

Re:It's a f...

[silentcoder]

My personal theory is that the most likely thing for any intelligent and technologically capable alien race to be doing is exactly what *we* are doing. Listen, and with a small budget - so only listening to a very small part of the spectrum from a tiny part of the sky. That golden record on voyager 1 is about the last major attempt we made at sending anything and it wasn't a very sensible one.

But if that was what economics led to here, why would we assume it would have other outcomes elsewhere ? Literally the only experimental sample of a technologically capable space-faring race we have - did this one.

So it's perfectly likely that there dozens of alien races within easy communications range of us all making a half-hearted attempt at listening and waiting for one of the others to talk first. All of them, in fact, hoping the outsource the expense of sending high-powered signals into a void where you don't know if anybody is listening, don't know if anybody who was listening would be able to understand it and don't even know in which direction to aim - to one of the others.

Exactly because sending messages is so incredibly difficult technically, and expensive, they may all have opted to just listen instead and, like us, hope that one of the others will figure out transmission first so they can justify the budget to build a transmitter to reply with.

Re:It's a f...

[DigiShaman]

Or we're all living in a simulator and the 'alien' expansion pack hasn't been released....yet.

Re:It's a f...

[Applehu Akbar]

All speculation about alien life tends to founder on the issue of small sample size, but already we observe that our machines 'like' space and extraterrestrial surface environments much better than our squishy carbon-based bodies do. So perhaps the leading candidate for LNAWKI would be something like our silicon-based emissaries. If the same process has been going on elsewhere we may find that (a) the most likely aliens we encounter will be machines, and (b) the encounter will be by our own machines.

Re:It's a f...

[angel'o'sphere]

LNAWKI what is that supposed to mean?
The only "useful" cough cough google results are two /. posts.

Re:It's a f...

[Wycliffe]

Sure, a species evolved to an undersea environment faces challenges in getting to their surface and beyond...

It would be much easier for a sentient undersea creature like an octopus to colonize the surface of their own planet than it would be for us to colonize the moon. As an added advantage, once a creature like the octopus has colonized the surface of their planet, they would already have most of the required technology to colonize other worlds. They would already have space suits, self-contained habitats, etc... The biggest problem I see (with an obvious LAWKI bias) is that most of our technology is electrical based and electricity experimentation would probably be a lot slower on a water based world.

Re:It's a f...

[Rei]

LAWKI = Life As We Know It
LNAWKI = Life Not As We Know It

There are lots of variants of the latter, while the former is pretty standardized.

Re:It's a f...

[Anonymous Coward]

I'm in the beta. It really sucks.

Re:It's a f...

[rtb61]

Apart from the illogic of an advance long lived species desire to remain bound to an unstable planetary surface, with variable stellar output and not being able to get out of the way of undeflectably large impacts. The greater stability of mobile orbital colonies and say city ships makes it logical, that while more primitive planetary bound elements of the society went extinct, the more advanced elements simply continued within more replaceable enduring environments. Not to mention the very strange idea, the more advanced the more stupid, rather than the more logical, advanced sufficiently to be able to plan maintain the stability of their society, bearing in mind the natural fracturing that would occur with expansion to the galaxy, the more advanced, longer lived and slower breeding, tending to create those new environments, leaving their dirt bound Luddites behind.

Re:It's a f...

[Walking The Walk]

LNAWKI what is that supposed to mean? The only "useful" cough cough google results are two /. posts.

LAWKI = Life As We Know It
LNAWKI = Life NOT As We Know It

Re:It's a f...

[Applehu Akbar]

Unfortunately, these geek acronyms tend to be English-specific. Some others you will encounter here:

RTKBA - Right to keep and bear arms;
TEOTWAWKI - The end of the world as we know it;
DYKWIA - "Do you know who I am?"
SJW - Social justice warrior

Re:It's a f...

[Scholasticus]

If I had mod points right now, I would mod you up with "insightful." You make two excellent points. Let's take the first one. Until we get a sample size larger than 1, we're speculating. Some of that speculation may turn out to be useful in the future, so why not keep doing it? I can't imagine how it could hurt anyone. Thanks for your post.

Re:It's a f...

[Rei]

On the other hand, some things can be easier underwater - for example, moving heavy objects (with buoyancy), long distance communication, etc. And of course the main drivers for advancement still exist, things like farming, hunting, armaments, defense, etc.

Electricity still works underwater (though AC not as well, and of course insulation is important). The same basic lines of progression work underwater. You can still make a "potato battery" type cell underwater with native copper, you can move lodestones next to a conductor, all of the usual stuff. Working metal underwater would be kind of an interesting challenge, of course - it would require better insulation and a good source of heat in a non-oxidizing atmosphere. But there are all sorts of oxidizers that can be made (or could exist naturally) other than O2, and other potential sources of heat beyond combustion.

Re:It's a f...

[sinij]

Or we're all living in a simulator and the 'alien' expansion pack hasn't been released....yet.

Lets hope humanity doesn't get nerfed in the next patch.

Re:It's a f...

[pipingguy]

Elon, is that you?

Re:It's a f...

[robi5]

> My personal theory is that the most likely thing for any intelligent and technologically capable alien race to be doing is exactly what *we* are doing.

Exactly - making ourselves go extinct over the cosmological blip of a few hundred years, by systematically undermining our own life conditions (us: global warming); by squandering non-replenishable resources (oil, gas, rare earth elements); by maintaining nation states that act like we don't share a planet (Putin's Russia, North Korea, China, Arab / Islam countries, USA etc.); by creating weapons that allow more and more destructive potential per user (nuclear, biological and autonomous weapons); and by resisting the completion of the surveillance police state and precrime, which are pretty much the only means to ensure that terrorists are killed before they can fake some nuclear attack, setting off WWIII, or release some plague that wipes out half of mankind and destroys economy as we know it.

Once we global-warm, war or terrorism ourselves back into a pre-technological tribe, we'll no longer have the chance for an industrial and thus technological revolution, for we have already used up most of the easily accessible oil and gas; no more radio telescopes sent to space.

Maybe we can't observe other intelligent life simply because chances are, any transmission is puny and fleeting on the cosmological scale, making reception incredibly unlikely. However maybe there are intelligent creatures that enjoyed their brief technological triumph, only to be followed by millions of years of an eternal Stone Age in the optimistic doom scenario when large bodied intelligent creatures can even survive their own technological windfall.

The rare few civilizations that survive the high mortality rate of technological infancy might evolve to such superpowers that they have unimaginable matter manipulation and computational capabilities in their hand. We, at such premature stage, already build vast, large simulations even without really trying (called games or machine learning environments). They (and maybe we) then go on building new universes which themselves beget alife, some of which may become powerful to build their own simulations. Then, we can conclude that believing that we are World #1 is the same anthropocentric view and hubris as geocentrism was a moment ago. Most probably we're currently on the bottom of a deep stack, hoping for adequate power redundancy and backup procedures in all layers above.

In conclusion, most of the fellow technological civilizations are behind us or ahead of us (time), or above us and maybe at some point, below us (simulation stack). All except the last of these are very unlikely to encounter and detect.

Re:It's a f...

[rossdee]

I thought the acronym was LBNAWKIJ
(the B stands for But)
Of course Intelligence is probably not confined to 'life' (eg AI)
and not all lifeforms are intelligent

Re:It's a f...

[Immerman]

Citation? It seems far more likely to me that it would crash into a star or planet - after all those present much larger targets for a given gravitational field. For a black hole you'd have to be on an almost perfect collision course before getting "sucked in" by it's gravity, or you'd just get slung right back out again on a hyperbolic trajectory. A 1 solar mass black hole would have an event horizon radius only about 3km (increases linearly with mass), so you'd have to get 200,000x closer to it before colliding than you would to the sun. Of course tidal forces would tear it apart before then, probably at somewhere around 200km, but that's still a thousand times closer than it could get to an actual sun.

Re:It's a f...

[Immerman]

Or that exponentially advancing technology rapidly encounters the relatively fixed physical constraints on the system with... interesting effects that don't typically involve trying to communicate with species too far away to meaningfully interact with.

In all the observed universe, cosmic inflation is the only thing that grows exponentially for more than the briefest of periods before being forcibly limited. What makes you think technology will be the exception?

Re:It's a f...

[Maow]

Except that it ignores subsurface oceans, which seem to be quite stable over long timeperiods and quite likely to be very abundant in the universe.

Agreed - and since it seems life on earth began in the oceans, it's a very likely proposition.

Sure, a species evolved to an undersea environment faces challenges in getting to their surface and beyond... but if we can get out of this deep gravity well after such a (geologically) short period of time after our species' evolution, sentient species in subsurface oceans with hundreds of millions or billion years on their "hands" would surely deal with the technical difficulties.

This I disagree with. An intelligent ocean-based life form is going to have to find a way to work with steel to get to space, and that can't be done below the surface in any way I've ever been able to imagine.

Without the ability to smelt iron / steel, etc. they just aren't going to be able to migrate on to land, never mind into the atmosphere, never mind space.

I'd be interested in any ideas you have on how they might actually achieve that - I've been unable to ever come up with a single one.

Re:It's a f...

[nine-times]

Sure, a species evolved to an undersea environment faces challenges in getting to their surface and beyond...

I also wonder how long it would take for an undersea lifeform to think about the larger universe. There's a lot of historical reason to say that our scientific progress has been driven, in various ways, by the curiosity formed when looking up at the stars and other celestial bodies. You don't see those if you're under water. You might not even see those if you had a different kind of atmosphere.

Re:It's a f...

[Immerman]

Well, except for the fact that most such signals would originate from very close to massive radio-noise transmitters (aka stars), and it's estimated that our listening technology probably wouldn't be able to detect a perfect twin of our civilization through the noise from more than a few light-years away. So there's *maybe* a small handful of the closest stars where we *might* be able to detect "ambient" signals from. Further than that, and they would have to be transmitting far more powerfully than we do.

The one exception is high-power military radar, which is often orders of magnitude stronger, and would be correspondingly easier to detect, but wouldn't necessarily appear to be an intelligent signal.

Also, while you're quite right about the time coordinating issue, you need to dial down your numbers a bit. From 10 billion light-years away an entire galaxy appears as barely a tiny smudge, if that, using our most sensitive detectors. Unless they were somehow blinking most of the stars in their galaxy in unison (as observed from Earth, which would require a very directional signal synchronized across tens of thousands of years), we wouldn't pick up even a hint of a signal.

Sadly, for now our technology is pretty much limited to listening for civilizations from relatively close within our own galaxy intentionally trying to contact us.

On the bright side we've been sending a pretty strong signal that our planet harbors life, or at least is something pretty unusual, for many millions of years. Just as we're beginning spectrographically analyze the atmospheres of exoplanets that pass between us and their sun, aliens residing close to Earth's orbital plane can do the same - and given the volatility of free oxygen, the concentrations of it in our atmosphere should make it clear that something very unusual is happening here.

Re:It's a f...

[Immerman]

I don't share your pessimism regarding recovery from a low-technology state. Yes, coal and oil allowed us to advance *very* quickly, maybe too quickly for our ability to make wise decisions, but they weren't necessary, they just temporarily relieved energy pressures on the population. There's very little you can do with coal and oil that you cant do with charcoal instead, you just can't do it on the same scale. A post-fossil-energy recovering society probably would not have ubiquitous cars, but there's no reason they couldn't have steam engines - nothing in the prerequisite technologies requires huge amounts of energy, you just couldn't can't scale out as quickly. Ditto wind turbines and eventually solar panels. Society would look very different, but most of the fundamental technology probably wouldn't.

The only real question would be how long it would take to recover. It might take many thousands of years to advance as far as we have in the last few hundred, but so long as at there were consistently at least a few clever individuals with some free time and resources on their hands, it would be nearly inevitable that we would do so. The only thing I can imagine might stop us is if medicine alone survived the "technological purging", and populations regrew to once again reach the carrying capacity of the planet so that there were no available free resource to spend. But that seems very unlikely - it seems likely there will always be plenty of individuals willing to oppress their neighbors to ensure a surplus for themselves, and such individuals usually enjoy showing off their wealth by sponsoring a few clever individuals to make entertaining toys and demonstrations. Which is pretty much how we got most of the way here to begin with.

Re:It's a f...

[Applehu Akbar]

We may be a long way from being able to detect extrasolar intelligence even just by radio/laser, but in the near future we will be able to characterize worlds like Europa, Enceladus and Mars. What we find or don't find at those places will shed a lot of light on what we might be able to find on extrasolar worlds. Keep in mind that these places are also in 'close panspermia range' of Earth. If we find life on Europa based on familiar DNA because of this, the possibilities for long-distance panspermia improve.

Re:It's a f...

[Triklyn]

the problem with that is always going to be... sentience.

intelligence is not guaranteed to be the best evolutionary advantage. Any complex life is almost certainly going to progress from single cells to multi-cells... or something similar to cells at least. And any intelligence is almost going to stem from complexity in a subset of those multicells. multicells that will have been specialized for intelligence and very little else. Brains are one of those huge resource investments that we need to constantly feed with sugar or we die.

multicellular life has been around for like, a billion years. and we've only just showed up to the party like, last week.

there could be millions of planets out there that are just filled with dinosaurs, bigger and bigger multicellular organisms that are just smart enough to hunt you down and eat you. Just smart enough to balance out the resource drain with the resource gain from having more mental faculties... and nothing more.

Remember, the masters of this planet are bacteria, ants outweigh us... and plants were here before us and will be here long after we're dead. evolution isn't directed and intelligence isn't guaranteed to be a net positive.

Re:It's a f...

[jpapon]

Why are you using the event horizon as your measure? That's the radius that *light* get's trapped at. Things moving slower than light will become trapped in its gravity well much further out than the event horizon.

A one solar mass black hole will have the same gravity well as a 1 solar mass star, won't it? Isn't that what "1 solar mass" means?!!?

Re:It's a f...

[HornWumpus]

That's not how orbital mechanics works. Two bodies passing pretty much won't capture each other.

Re:It's a f...

[Immerman]

The event horizon something special - the boundary beyond which normal physics breaks down since not even light can propagate information outwards. Cross the event horizon and you become part of the black hole and we have no idea what happens to you. Remain outside it, and you remain part of the normal universe. And in the normal universe nothing gets "trapped" except in orbit, and gravity acts sort of like a perfect frictionless spring, which makes that difficult

As HornWumpus said, gravitational entrapment is difficult. If you have something approaching a gravitational source there's really only three options:
1) It's already in orbit (which doesn't apply to incoming objects)
2) It hits something
3) It follows a hyperbolic path past the focus (a so-called gravitational slingshot) so that it leaves with exactly the same relative speed as it approached with.

Basically space is, as a rule, the sort of frictionless infinite plane that physicists dream about, and objects on a simple (single-body) orbital path have a constant orbital energy: kinetic energy (speed) + gravitational potential energy (distance) = constant. As something gets closer to a star it will continuously lose potential energy, while gaining exactly the same amount of kinetic energy in the form of speed. Assuming it misses the star, it will then zoom past and start slowing down, losing speed at exactly the same rate that it gains potential energy. Eventually it will reach the same distance and speed as it started with, only position and direction will have changed. Energy can not be created or destroyed.

Gravitational capture requires something more complex to happen to slow you down. Collision is the simplest one - it transfers kinetic energy to the object you hit, as well as converting some (or much) of it into impact heat, slowing you down. If you slow down enough, then your kinetic energy will no longer be greater than the potential energy you lost approaching the star, and you will be trapped in orbit. The same basic thing happens if you "collide" with a gas cloud - trillions of gas-molecule impacts gradually slow you down while heating your surface.

The other possibility for gravitational capture is more complicated and requires having planets, and basically involves one (or usually several) gravitational slingshots around the planets to reduce speed without any direct collisions. Basically the same rules apply as for any other slingshot maneuver - you will leave the planets gravitational influence with the same speed you approached, but that's relative to the planet, which is also moving relative to the sun, which allows for some orbital-mechanical sneakiness.

Picture it like throwing a perfect superball, one that bounces back with exactly the same speed as it hits, at the front of an oncoming car. At the moment before impact the speed difference with the car will be (throwing speed + car speed), and so it will bounce off with (throwing speed + car speed), relative to the car (the surface it bounced off of). Which will be (throwing speed + 2*car speed) from your perspective - essentially the ball has "stolen" some kinetic energy from the car to get going much faster than you threw it, but since the car is so much more massive you probably can't tell that it has slowed down.

Alternately, if you throw at the back of the car... well first off, obviously you'll have to throw faster than the car is driving away to hit it at all, but in the moment before impact the speed difference will be much lower than before, only (throwing speed - car speed), and after bouncing the ball will come back at you with a speed of (throwing speed - 2*car speed), so you have to throw at least twice as fast as the car to get the ball to actually return, otherwise even after it bounces it will still be moving away from you. In this case the ball has given some of its speed to the car.

That's the basic principle behind a gravitational slingshot - approach a planet from in front of it and you'll gain speed

Re:It's a f...

[Anonymous Coward]

IMHO the most likely ones to conquest space are our civilization artificial children (silicon or something else) they can adapt their shape to whatever is needed, being artificial may allow them to be quasi immortal which mean ability to travel long distances if somehow was needed and ability to use and exploit any environment, including different gravities or none, hight radiation and heat levels, or frozen temperatures...and the same that apply to our civilization will apply to any other alien civilization out there
We or the aliens may not survive but if we / they reach a level where we / they can manufacture a clever enough AI and advanced materials engineering the civilizations artificial children will
And the most likely reason they don't see each other, given the enormous distances required for interstellar travel and the huge quantity of goodies floating around the typical star system, why bother?

Re:It's a f...

[houghi]

And why would they leave? The oceans are 3D, on land we only have 2D, the surface of said land. Sure there are some animals that can use the air, but nothing does it all the time.

So life gets all this space. The surface is already several times larger than what we have on land, never ,ind that life here could go from the depth to the surface. But noooo, let's go on land where there is less space.

Re:It's a f...

[Agent0013]

This I disagree with. An intelligent ocean-based life form is going to have to find a way to work with steel to get to space, and that can't be done below the surface in any way I've ever been able to imagine.

Perhaps that just means you lack imagination or aren't really trying. What about underwater lava flows. If there is an intelligent underwater species they are going to start investigating their world. Or the invention of pumps and containers. I guess it would be impossible for an air living people to invent something like a vacuum chamber? I mean, that would never happen since they can't live without air. And they would not be able to experiments in this vacuum chamber would they? An underwater people could invent the same thing and perhaps try experiments with putting air in the chamber. Then you discover that metal can melt in high heat, etc.

Re:It's a f...

[TharMonk]

Actually, underwater species would have significant trouble climbing the tech tree, as we have. We already have intelligent creatures in our oceans, but none of them are improving their tech... They never get past the pre-civilization foundations of discovering fire, on which a huge portion of our tech tree is based. Climbing out of the ocean may well be a prerequisite to building significant tech.

Re:It's a f...

[gzuckier]

Except that it ignores subsurface oceans, which seem to be quite stable over long timeperiods and quite likely to be very abundant in the universe.

Sure, a species evolved to an undersea environment faces challenges in getting to their surface and beyond... but if we can get out of this deep gravity well after such a (geologically) short period of time after our species' evolution, sentient species in subsurface oceans with hundreds of millions or billion years on their "hands" would surely deal with the technical difficulties.

And of course there's also the possibility of LNAWKI, but let's just stick with LAWKI for now.

My personal suspicion is that a wide variety of factors work together to keep complex life rather rare on a per-planet basis, great distances dilute any signals from any that do achieve sentience, and the speed of light and difficulty of propagating a civilization outward at near that limit keeps the vast majority far away. Basically, rarity + dilution. But that's just my suspicion.

Just blueskying here, but even if a subsurface underwater species develops technology, it would seem that EM radiation wouldn't be a feature, given the nature of water, and that's what we're looking for.

Re:It's a f...

[gzuckier]

> My personal theory is that the most likely thing for any intelligent and technologically capable alien race to be doing is exactly what *we* are doing.

Exactly - making ourselves go extinct over the cosmological blip of a few hundred years, by systematically undermining our own life conditions (us: global warming); by squandering non-replenishable resources (oil, gas, rare earth elements); by maintaining nation states that act like we don't share a planet (Putin's Russia, North Korea, China, Arab / Islam countries, USA etc.); by creating weapons that allow more and more destructive potential per user (nuclear, biological and autonomous weapons); and by resisting the completion of the surveillance police state and precrime, which are pretty much the only means to ensure that terrorists are killed before they can fake some nuclear attack, setting off WWIII, or release some plague that wipes out half of mankind and destroys economy as we know it.

Once we global-warm, war or terrorism ourselves back into a pre-technological tribe, we'll no longer have the chance for an industrial and thus technological revolution, for we have already used up most of the easily accessible oil and gas; no more radio telescopes sent to space.

Maybe we can't observe other intelligent life simply because chances are, any transmission is puny and fleeting on the cosmological scale, making reception incredibly unlikely. However maybe there are intelligent creatures that enjoyed their brief technological triumph, only to be followed by millions of years of an eternal Stone Age in the optimistic doom scenario when large bodied intelligent creatures can even survive their own technological windfall.

The rare few civilizations that survive the high mortality rate of technological infancy might evolve to such superpowers that they have unimaginable matter manipulation and computational capabilities in their hand. We, at such premature stage, already build vast, large simulations even without really trying (called games or machine learning environments). They (and maybe we) then go on building new universes which themselves beget alife, some of which may become powerful to build their own simulations. Then, we can conclude that believing that we are World #1 is the same anthropocentric view and hubris as geocentrism was a moment ago. Most probably we're currently on the bottom of a deep stack, hoping for adequate power redundancy and backup procedures in all layers above.

In conclusion, most of the fellow technological civilizations are behind us or ahead of us (time), or above us and maybe at some point, below us (simulation stack). All except the last of these are very unlikely to encounter and detect.

i wonder if fossil carbon fuels might not be just a fluke of terrestrial history, and that other planets might not discover a similar windfall of energy, which prevents them from getting the boost in mechanical technology that leads to space travel.

Re:It's a f...

[Maow]

This I disagree with. An intelligent ocean-based life form is going to have to find a way to work with steel to get to space, and that can't be done below the surface in any way I've ever been able to imagine.

Perhaps that just means you lack imagination or aren't really trying.

Okaaaay - do enlighten us then.

What about underwater lava flows.

Right, they'll just start molding that lava with their fins / flippers / tentacles? If they use available rocks to work the lava, how do they then forge metals with a controllable source of heat?

If there is an intelligent underwater species they are going to start investigating their world.

Maybe, maybe not. Haven't seen any dolphins come up on to the beach to investigate the parts of the world they aren't familiar with - and they breath air.

Unless that's what mass beachings are all about, but then it's not very intelligent of them to go ashore en mass as a form of exploration.

Or the invention of pumps and containers. I guess it would be impossible for an air living people to invent something like a vacuum chamber? I mean, that would never happen since they can't live without air. And they would not be able to experiments in this vacuum chamber would they?

Do you find being a snarky prick makes your life easier in some way?

Do tell - how to create a vacuum chamber with materials available to ocean-dwelling (sub-surface) creatures?

An underwater people could invent the same thing and perhaps try experiments with putting air in the chamber. Then you discover that metal can melt in high heat, etc.

Since I'm the one lacking imagination, help me out here - how?

Seems fire was crucial to bootstrap civilization and I'm finding it tough to imagine how to do it under an ocean, whether of water, methane, or something else, and you've only offered some hand-waving speculation without anything concrete enough to make it seem any more plausible.

Re:It's a f...

[AK Marc]

by squandering non-replenishable resources (oil, gas, rare earth elements);

You lost me there. Rare Earth Elements aren't rare. They are "rare" because they aren't found in large concentrated pockets. They are not rare in the sense that there aren't enough of them. There's enough, they are just not cheap to extract because of the low-concentrations of them. Oil and gas are energy, something we have enough of. More solar lands on the surface of the Earth than we could ever use, stored solar in the form of oil is convenient, but not necessary.

Re:It's a f...

[toddestan]

i wonder if fossil carbon fuels might not be just a fluke of terrestrial history, and that other planets might not discover a similar windfall of energy, which prevents them from getting the boost in mechanical technology that leads to space travel.

Most fossil fuels date back to the Carboniferous era, where basically trees developed lignin, but it was millions of years before fungi and bacteria developed that were able to break it down effectively. Needless to say, vast amounts of dead trees ended up buried and formed many of today's fossil fuels. It doesn't seem likely that given a do-over from the beginning that the same situation would occur and we wouldn't have all these fossil fuels.

Though I don't know if it's a good thing, as burning all these fossil fuels and releasing all this long-sequestered carbon dioxide could also be our downfall. I have to wonder if the universe is littered with the remains of civilizations that flourished for a few hundred years before completely screwing up their home planet. Perhaps the best situation would be to have enough fossil fuels to get things bootstrapped but not enough so that we'd have to move to other energy sources before civilization became completely dependent on them.

Its...

[invictusvoyd]

The mystery of why we haven't yet found signs of aliens may have less to do with the likelihood of the origin of life or intelligence and have more to do with the rarity of the rapid emergence of biological regulation of feedback cycles on planetary surface

Monty Python

err .. I mean It's the distance .. the distance

Re:Its...

[khasim]

Yep, it's the distance.

And whatever constitutes "teeming with aliens". Is that 10 planets per galaxy? 100? 1,000?

And the time involved. How long ago did life start on Earth? How many mass extinctions have there been? Would ANY of those have been detected by aliens on their home planet using technology equivalent to ours?

The Fermi "paradox" is based upon alien expansion. Which is, in turn, based upon tech advances that we don't have.

The galaxy could be "teeming with aliens" that we cannot detect and that we cannot reach with our technology. Nor can they detect us or reach us.

Re:Its...

[PolygamousRanchKid]

Monty Python

Maybe the aliens aren't quite dead yet . . . they are merely resting?

Tired and shagged out after a long squawk . . . ?

Or it's intern-planetary censorship . . . their governments are blocking them from contacting us . . . ?

Re:Its...

[drinkypoo]

We don't even have the Concorde anymore, or the SR-71, in some ways we've gone backwards.

The only way in which the Concorde and SR-71 were not primitive is that they were fast. But the mindset of burning up that much fuel so that Rod Stewart can get a haircut in another country and still wind up looking like an aged lesbian or so that we can spy on another country so that we can more effectively wage a cold war against them is seriously fucking backwards.

Getting rid of the Concorde and the SR-71 might seem technologically backwards, but in fact, it is a huge step in the correct direction. Do you seriously suggest that advanced aliens would be flying around at supersonic speeds for no good reason? How inefficient.

Re:Its...

[invictusvoyd]

Do you seriously suggest that advanced aliens would be flying around at supersonic speeds for no good reason? How inefficient.

Supersonic in interstellar/interplanetary terms would be like going cross country on a push bike

Re:Its...

[drinkypoo]

Supersonic in interstellar/interplanetary terms would be like going cross country on a push bike

In space, no one can hear you trying to exceed the speed of sound.

Re:Its...

[drsmithy]

To get a technological head start and a head start out in space an alien species would been part of an evolutionary process that skipped whatever their equivalent of dinosaurs would have been and gone directly to intelligent life capable of technology.

Say what ?

We're probably talking about a timeframe measured in tens of thousands of years at most. On planetary timescales even a eye blink analogy is woefully inadequate.

That said, I'm personally of the belief that most intelligent/technologically advanced societies destroy themselves, either completely or to the point where escaping the gravity well (or even mid-20th century tech level) is unattainable. Like we probably will in the next 50-100 years.

Re:Its...

[Zocalo]

No, that's not it. They are clearly pining for the fjords. It's not been quite the same since Magrathea shut up shop. That Slartibartfast fellow just to do some amazing work on the crinkly bits...

Re:Its...

[Tukz]

In space, a snail can exceed the speed of sound.

Re:Its...

[Anonymous Coward]

We're probably talking about a timeframe measured in tens of thousands of years at most. On planetary timescales even a eye blink analogy is woefully inadequate.

But there haven't been enough time for planetary timescales yet. The universe is estimated to be 13.8 billion years. A large part of that have been without heavy elements since stars have to take shape and die in several cycles to create the heavy elements life relies on.
With an Earth of an estimated age of 4.5 billion years similar planets could not have formed much earlier and with the time it took to form multicellular life here it is not reasonable that any other intelligent species would have gotten a head start on a planetary timescale.
Another intelligent life form that has been around for a million years is plausible, a billion years is not, not unless you speculate that life would be possible based on lighter elements than what Earth life requires.

Re:Its...

[silentcoder]

>To get a technological head start and a head start out in space an alien species would been part of an evolutionary process that skipped whatever their equivalent of dinosaurs would have been and gone directly to intelligent life capable of technology.

Firstly - why not ? We have no proof that there were NOT technologically advanced dinosaurs, at best we have strong reason to doubt there were spacefaring dinosaurs. You are underestimating just how massive an amount of deep time 65-million years was. Dinosaurs could have built cities five times bigger than New York and not a shred would have survived for us to find. If we go extinct tomorrow, it's unlikely that in 10-million years there will be any evidence whatsoever that we existed - except maybe a few primate fossils, even our best mummies can't make it that far. A hundred million ? Not a chance, by that point even our satelites would have decayed and crashed. The last evidence of our existence that may be around would be the bits of junk Apollo left on the moon and any future paleontologists (whether evolved here or elsewhere) that found that evidence would mostly wonder what the hell a Richard M. Nixon was... think about it, they would not even be sure whether it was left there by an earth-born species that reached the moon - or a long-lost lunar species that had a great council to end a war at that spot.

Secondly - your argument is flawed because that's not how time works, time is relative and doesn't happen at a constant rate. Planets that rotate their stars slower have physically existed longer than ones that move slower. So two planets around the same star, in different orbits, which orbit in the same timeframe, that formed together at the same time - the outer one will be significantly younger because time slows down as you speed up. It may be a matter of seconds per rotation - but there's been many billions of rotations for those to add up. And planets around more massive stars are regardless of when they formed relative to the big-bang, have had less time pass on them than those around smaller stars - because time slows down near bigger gravity wells.

The amount of "time" that passed on the surface of a planet is only very vaguely connected to the age of the universe and even to the age of that planet (which we measure relative to the age of the universe). The one decidedly does not offer any indications of the other. The only reason they happen to be the same on earth is because we happen to measure "years" by the time it takes our planet to rotate, but Jupiter formed at the same time as Earth did - and quite a lot less time has passed on Jupiter than on Earth. Even less have passed on the sun.
This is, actually, one reason why - if there is life on Io or Europa - that life is likely to be "bacterial" rather than fishes - those moons circle a massive planet, any life there has had significantly less time to evolve than life on earth has had. No, I don't feel like doing the math to figure out how much.

Re:Its...

[kilfarsnar]

What we see is *it* as far as technology goes. We might get a few more generations of CPUs, but we'll still see the same airplanes, rockets, and cars as pretty much 50 years ago. We don't even have the Concorde anymore, or the SR-71, in some ways we've gone backwards.

Welp, might as well shut down all R we've invented and discovered everything! It didn't take too long, did it?

Re:Its...

[kilfarsnar]

That should say R & D...

Re:Its...

[Applehu Akbar]

"We don't even have the Concorde anymore, or the SR-71, in some ways we've gone backwards."

But fortunately, there is intelligent life in Asia.

Re:Its...

[stealth_finger]

Yep, it's the distance.

And whatever constitutes "teeming with aliens". Is that 10 planets per galaxy? 100? 1,000?

And the time involved. How long ago did life start on Earth? How many mass extinctions have there been? Would ANY of those have been detected by aliens on their home planet using technology equivalent to ours?

The Fermi "paradox" is based upon alien expansion. Which is, in turn, based upon tech advances that we don't have.

The galaxy could be "teeming with aliens" that we cannot detect and that we cannot reach with our technology. Nor can they detect us or reach us.

To be fair, if we never hard the dark ages and big stretches of time that religion was in charge and very little actual progress was made we would probably be way ahead of where we are now.

Re:Its...

[DigiShaman]

Whether you call it transcendence or evolution, I suspect all life of spacefaring advancement progressed in the following way universally.

Single-cell organism (on planet) --> Multi-cellular organism (on planet); such as Homo sapiens --> Tool of Homo Spiens; such as AI and robotics (on planet) --> Super AI machines (OFF PLANET); can bend space/time, warp, and hack the laws of physics beyond our comprehension!

It will be AI machines that will fill outer space. There might even being alien Super AI that engages in warfare against our own Super AI. Meanwhile, biological creatures will remain on the planet with the machines acting as the true host planet's ambassadors to outer-space. In fact, technically Voyager was our first intergalactic ambassador if only broadcasting the message as a monologue.

Re:Its...

[Jason Levine]

They might even be communicating with each other but using a communications method that we can't detect. Imagine if you had a medieval civilization on a planet and an advanced civilization blasted radio waves all over to communicate. The medieval folks wouldn't have the technology to intercept and interpret the radio waves so the advanced civilization would be invisible to them.

Re:Its...

[drsmithy]

I think you're missing the point.

An alien civilisation with a mere few hundred years head start on humanity would probably have technology that was nearly magical to us if we were to meet them today.

Stretch that out to a few tens of thousands of years - still utterly irrelevant on a timescale measured in billions of years - and you've easily got the kind of civilisation the OP was talking about. Undetectable by us and completely uninterested in us.

From memory, even with the technology we have today we could colonise the entire galaxy in a million years. Not that I think any civilisation could remain stable for that long, but consider it in the context of the mere hundreds or thousands of years "head start" required as discussed earlier.

Re:Its...

[Opportunist]

All true, but look at our history of what we haughtily call civilization. It's a mere 10,000 years. And of those, we've made more technological progress in the last 200 years than the 9800 years before.

And now imagine they're off by "only" 1000 years, which is pretty much nothing on a time scale that deals with cosmological events.

Re:Its...

[TheRaven64]

I think that you're contradicting yourself. The Earth has been around for 4.5 billion years, so for an alien life form to have been around for that long would require only that it reached intelligence a billion years earlier than us, or when Earth was 3.5 billion years old. Multicellular life had been around on Earth for a while then. And that's assuming that their planet cooled at the same time as ours - Sol isn't one of the oldest second-generation stars.

Re:Its...

[angel'o'sphere]

if we never hard the dark ages
Dark Ages does not mean what you think it means.

The civilization of man kind likely never was "dark".

"Dark Ages" are the periods of time about which we have not much written testimonies, that is all. Perhaps the library burned down, perhaps people like Herodot did not live at that time.

and big stretches of time that religion was in charge and very little actual progress
Wow, and where is the connection between religion and progress? Or no progress? Considering that most scientists are members of a religion ...

little actual progress was made we would probably be way ahead of where we are now.
Perhaps because people in older times lacked a bit of imagination? I consider slavery the main reason for lack of progress ...

Considering that the steam engine was invented ... 50 AD. However neither the inventor nor the "scientists" seeing it had any idea what to do with it. So it was only used for "magical tricks" like opening huge temple doors without human power.

And talking about "Dark Ages", 50 AD is the time we know that one invented a steam engine. (Heron of Alexandria, called: "the Mechanic") What we don't know is: how often before the steam engine already once was "discovered" or "invented" especially in other parts of the world like South America or Asia.

Perhaps instead of ditching religions you should read a bit about it? A start would be literature mentioned here: https://en.wikipedia.org/wiki/...

Either that is thousands of years old hard science fiction or there are indeed pretty dark ages before ~6000 years ago.

Re:Its...

[Anonymous Coward]

I think such wars would be evident to us, in the form of fronts of disappearing stars being lifted and turned into long lived energy sinks, and massively energetic explosions where those fronts meet.

No, I think ASI guardians will simply maintain the welfare of their charges, who will inevitably upload so they can take advantage of speedup (time for them passes 1,000,000x faster than for us, as their senses and thoughts become lightspeed rather than bioelectrical). They simply don't care about the "real" world, because it goes so very, very slowly, and they are naturally far, far more intelligent than anything that could possibly live in that world (including potential aggressors). If they wanted a "real" world, they would just simulate one at a much faster speed so they could study it in a reasonable amount of time (hence we are likely one of an infinite series of simulations, but not optimized as games or anything like that, but rather highly advanced physics simulations that happen to support life in a few corners here and there within).

I think there is a significant probability that the silence we see is due entirely to this effect. Otherwise, we would see evidence of galaxy scale civilizations SOMEWHERE, even if there was only one within our Hubble volume. The universe is too vast, and life too common and diverse for us not to see at least one ultra successful civilization lifting stars somewhere.

Re:Its...

[Dan1701]

One thing to bear in mind is that life here existed in the form of anaerobic bacteria for a staggeringly long time. Photosynthesis began as a way to split hydrogen sulphide into useful hydrogen ions and a useless waste product of elemental sulphur, which was also usefully inert. Early photosynthesis therefore didn't require much in the way of biochemical sophistication to operate; the waste sulphur is where some large sulphur deposits originated.

That changed with a mutation which let the photosynthesis split not hydrogen sulphide, but water into useful hydrogen and (to anaerobic bacteria) highly toxic and dangerous oxygen. That initially wasn't all that big a problem to early water-splitters; the oceans they were in were rich in iron-II salts which readily absorbed oxygen to become insoluble iron-III salts (this is where the banded iron rock formations come from).

Everything changed when most of the iron-II in solution in the early earth's oceans was used up. Oxygen levels slowly rose, and virtually all bacterial species either adapted or went extinct. Oxygen is toxic to most bacteria.

I would hypothesise that most alien worlds either never make the switch from anaerobic atmosphere to aerobic one, or fail to establish a homeostatic oxygen-nitrogen atmosphere quickly enough and effectively enough to become self-regulating.

Re:Its...

[angel'o'sphere]

even with the technology we have today we could colonise the entire galaxy in a million years
No we could not. The milkyway has a diameter of about 100,000 light years, give or take.
To fly every where you would need at least 0.1c and may not be to far at the edge, which unfortunately is the case for the solar system.

With our technology we have no means to accelerate and decelerate a space ship with life on it to 0.1c.

You probably could "seed" the whole galaxy in 10 - 100 million years, but not in 1 million.

And bottom line: why would anyone really want to do that? Except for the curiousity like "wow lets dive as deep as we can and look what is there" there never will be a big appeal to space for most of the humans.

Would i like to go out visit the next star system? Yes, absolutely.
Would I like to go out to the next star system on a journey that will take so long that I definitely die on the way before we reach the destination? Absolutely not. There are much more fun activities I can do here on earth than on a what ever luxuries it might have, space ship.

Re:Its...

[angel'o'sphere]

Not a chance, by that point even our satelites would have decayed and crashed.
How so?

As most satellites are in GSOs ... they literally never will "crash".

Re:Its...

[cyberchondriac]

I've thought the same thing, but then remembered in the early universe, stars were probably a lot larger and hotter, and would've had dramatically shorter life spans than yellow darves.. some of those supergiants only last 10 million years. I guess the question is, how many supergiants were there to go supernova in the first billion years or so of the universe?
Another plausible scenario to the Fermi paradox is that our particular galaxy is just kinda dead. For all we know, Barnards Galaxy, or M32, or M33 are full of life.

It has been looked into but I think these guys are perhaps expecting too much of alien civilizations. http://www.scientificamerican....

Re:Its...

[stealth_finger]

You gonna app your way across the galaxy?

Not if you're some kind of Luddite. Where did that guy go?

Re:Its...

[tburkhol]

And whatever constitutes "teeming with aliens". Is that 10 planets per galaxy? 100? 1,000?

The optimistic estimates I see are closer to 100 million. In a galaxy of 20 billion stars, over 14 billion years, I'm ok with that. It suggests there might be another life (at some time) about 80 light years away. That's a whole lot of too far away to detect.

These guys are using the other common answer to the Fermi paradox: life doesn't last very long. "Very long" on the galactic time scale being a few hundred million years. Maybe they have a new argument for why it doesn't last very long, but it's not a fundamentally new argument.

Re:Its...

[stealth_finger]

So you completely missed the point, maybe the mention of religion got you all hot under the collar. For Dark ages, read middle ages, when much of Europe was under the iron rule of the pope leading to such wondrous events as the crusades and inquisition, when for a good 1000 or so years humans made very little technological progress. Sure things got invented and scientific progress was made but not without great effort and sacrifice. Remind me again what happened to people who dared to suggest outrageous things like maybe the Earth wasn't the centre of everything or even just disagree with Church teachings. It usually ended up pretty bad for someone. Religion ruled so tightly you had be in it or at least pretend to even be acknowledged by society, if you openly said I don't believe in god, you would usually end up dead before too long so people went with it because for the most part they probably enjoyed being alive.

As you say the first steam engine was invented in the first century, how long did it take to move up a level? around 1700 years by my count. Most people associate the steam engine with the industrial revolution, as Christianity was beginning to loosen it's grip over the continent. Just look at how much progress we've made since then. Just look at the countries today which are still heavily ruled by religion, as in are the government. They're very resistant to change and anything against the status quo, sure they use the technology available and stuff comes out of there but still. Look at Israel. There's some ultra ortadox sect that say girls over 5 shouldn't ride bikes and the internet isn't kosher. Do you hear some of the ridiculous claims clerics from UAE and others make? Don't take my post as an attack on Christianity, all religions are as bad as each other in that respect. They still stone people to death over there like a bunch of fucking savages and then get all uppity about it when anyone says anything about it.

Re:Its...

[moosehooey]

What about the em-drive? That is new physics and would even be applicable to space travel.

Re:Its...

[StikyPad]

I think that's a bit like saying "if I hadn't wasted all of those toddler years playing with toys, I could have graduated high school earlier." Human society advanced at exactly the pace it was capable of. It only seems wasteful in retrospect because we know better, but hindsight is always better than foresight. Besides, a few hundred or thousand years is nothing in geological terms. We wasted a lot more time living in caves and grunting than we did in the Dark Ages.

Re:Its...

[StikyPad]

We have no proof that there were NOT technologically advanced dinosaurs

I think we have quite a lot of evidence, actually, given how little technology (none) has been discovered on or around dinosaurs, or at all, anywhere, predating humans. https://en.wikipedia.org/wiki/...

Re:Its...

[Anonymous Coward]

That is not dead which can eternal lie,
And with strange aeons even death may die.

Re:Its...

[stealth_finger]

Maybe, I'd say it's closer to pissing away your teens then trying to get on track at 20.

Re:Its...

[angel'o'sphere]

For Dark ages, read middle ages, when much of Europe was under the iron rule of the pope leading to such wondrous events as the crusades and inquisition, when for a good 1000 or so years humans made very little technological progress.
Calling this a "Dark Age" is simply wrong as I pointed out.
No idea why you insist upon it.

The fact that there was not much progress ... well, it is like that. Any idea how they should have made more? No? So ... leave it? You can pick random periods of time where mankind made not much progress.

Bottom line we only have progress since 1870 ... what has that to do with middle ages? Nothing. What has that to do with Dark ages, nothing either. What has that to do with religion? Again: absolutely nothing.

Middle Ages and Dark Ages are not the same thing, get it or leave it.

Re:Its...

[StikyPad]

Regardless of what age it happened, if people were capable of making better decisions, then they would. (Ignoring that "better" is a very vague term when it comes to the progression of humans either as individuals or collectively). At least that's what causality seems to imply...

Re:Its...

[robi5]

You're missing the point. Let's assume there's some necessary planetary time for complex life to evolve. To be very generous toward your argument, let's start the clock with the Cambrian explosion. Which was 500 million years ago. According to our understanding, intelligent life could have evolved earlier or later than how it happened on our planet. The GP mentions dinosaurs. Maybe they'd have evolved into a civilization, had they not been swept by some cataclism (or their own self-destroying technological civilization, haha). Let's say dinosaours evolved 250 million years ago and were dominant 125 million years ago.

Now, again, generously assuming that civilizations need some specific amount of time to evolve, and we're smack middle of this distribution, we could still draw up e.g. a Gaussian distribution with a mean of 'now', and one standard deviation equalling, say, a 100 million years, but to be favorable to your argument, let's use an approximation that one standard deviation is only 10 million years (a very short period on the planetary scale). It means that 49.99% of all technological civilizations appeared 1000 years or more ahead of us, and of course 1000 years is a long time of technological evolution if we count it from e.g. radio or even steam.

While travel time of light factors in, there's a LOT of stars in the neighborhood of, say, 1000 light-years.

I hope your argument isn't that we humans and our planet Earth is miraculously the fastest possible member of the race toward intelligent life and technological society, give or take a few decades only.

Re:Its...

[110010001000]

Science fiction. Do you know the difference between science fiction and reality?

Re:Its...

[robi5]

While I'm in complete agreement with all these, let's consider the point more metaphorically, what is 1 million vs 10 or even a 100 among friends?

For some reason I feel that even at current technological advancement, given enough time and somehow dodging the bullet of making ourselves extinct, it would be possible to send enough bacteria and plants to Mars to slowly terraform it, and/or machine large enough enclosed habitats to make life sustainable. It's probably possible to build a ship with currently known tools and materials that can fly to the nearest known rocky exoplanets, which are 13.8 light years away. A sufficiently large space station can be eventually assembled in orbit and could harbor life for the long centuries the travel takes, and making hundreds of these vessels would protect from the possibility of collisions or some bad virus killing everyone aboard.

While colonizing Mars is a good testing ground, most of the materials and interstellar ship building would of course come from mining the asteroid belt - once there's enough robotics up there, incredibly huge or numerous things can be built. Given enough petri dishes of sperms, eggs and seeding organisms, a dozen couples reaching an exoplanet with heavy machinery to make habitat can spawn a genetically diverse life.

Re:Its...

[andydread]

Voyager is barely interstellar let alone intergalactic. I doubt it will ever make it to intergalactic space in the lifetime of our solar system

Re:Its...

[alexhs]

To be fair, if we never hard the dark ages and big stretches of time that religion was in charge and very little actual progress was made we would probably be way ahead of where we are now.

That's a European-centric view. Dark ages were an European thing; at the same time Arab, Persian and Chinese cultures were flourishing.
And if you're going with any significant culture at any time not being prosper as being a dark age, we didn't left these yet as many middle-eastern and African nations aren't currently stable enough, and many Asian nations still are too poor.

Re:Its...

[robi5]

> There have been no new fundamental discoveries in almost a century now.

Velcro?

Re:Its...

[vux984]

You are underestimating just how massive an amount of deep time 65-million years was.

What would a radioactive waste storage look like in a 100M years? Ridiculously stable. Dry. Sealed from elements. Even if it literally just disintegrated in place, the odd mix and ratios of remaining isotopes at the site, surrounded by solid geologically stable rock millions of years older... would clearly suggest something unnatural.

Or perhaps a lego mini-fig -- tey'll soon outnumber humans after all.
http://xkcd.com/1281/

Surely bunches of those highly stable bits of plastic will find themselves some place safe to hide... preserved in amber, or tarpits, or trapped in some glacier, at the bottom of the ocean, or in a salt mine... there are billions of them, so probably all of those things will happen.

And we have things like modern jewelry. Laser engraved diamonds, set in platinum bands. Stored inside fire proof safes... some which would end up buried in stable places... even bunkers. What's 65 million years going to do to that?

Secondly - your argument is flawed because that's not how time works, time is relative and doesn't happen at a constant rate. Planets that rotate their stars slower have physically existed longer than ones that move slower. So two planets around the same star, in different orbits, which orbit in the same timeframe, that formed together at the same time - the outer one will be significantly younger because time slows down as you speed up. It may be a matter of seconds per rotation - but there's been many billions of rotations for those to add up.

Ok... so lets put some figures into those numbers ... say 11 seconds for "a matter of seconds". And how about 4.6 billion for for "many billions" as that's the age of our solar system measured from earth's perspective at least.

11 seconds x 4.6 billion rotations = 1603 years. I don't think we need to worry too much about relative ages of the planets.

This is, actually, one reason why - if there is life on Io or Europa - that life is likely to be "bacterial" rather than fishes - those moons circle a massive planet, any life there has had significantly less time to evolve than life on earth has had. No, I don't feel like doing the math to figure out how much.

You really think its going to be billions of years though? I'm pretty skeptical. Maybe you should do the math.

Re:Its...

[kellymcdonald78]

DNA, genetics, human genome project, CRISP, yup no fundamental discoveries at all

Re:Its...

[judoguy]

In space, a snail can exceed the speed of sound.

Briefly.

Re:Its...

[judoguy]

Unless... He has a spacesuit

Re:Its...

[stealth_finger]

Of course it's a European centric view. I was talking technological progress rather than culture. You could probably argue out of those three china had the most progress and was least religious but they had all kinds of other shit going on. Arabs were kinda into science but as I understand it that was more astrology and math. Persia's not even really a thing anymore but I'm not sure how relevant that is. the current state of Africa is kinda our fault too but both they and a lot of Asian nations are still deeply religious now. It's not the religion per se keeping them down but those in charge do very much abuse it to keep the status quo.

Re:Its...

[painandgreed]

Firstly - why not ? We have no proof that there were NOT technologically advanced dinosaurs, at best we have strong reason to doubt there were spacefaring dinosaurs. You are underestimating just how massive an amount of deep time 65-million years was. Dinosaurs could have built cities five times bigger than New York and not a shred would have survived for us to find. If we go extinct tomorrow, it's unlikely that in 10-million years there will be any evidence whatsoever that we existed - except maybe a few primate fossils, even our best mummies can't make it that far. A hundred million ? Not a chance, by that point even our satelites would have decayed and crashed.

There will still be lots of evidence that we existed and likewise there is similar evidence that dinosaurs did not have a highly advanced technological society. The matter of the fact is that although our artifacts and relics may have deteriated, we have long since created disturbances in the geological records with mining to form evidence on the period of tectonic crust renewal. Evidence that we have mined gold, silver, copper, iron, etc let alone quarries where we have mined limestone, marble, and other mountains of hard stone will be buried in the earth and be obvious to anybody looking. Looking at dinosaur fossils, we can tell where they have dug into the earth to create nests for eggs, and we have never seen evidence that there are fire pits, mining, or even stone tools. Layers of stone such as marble, granite, and limestone will not heal. That there are still ore, oil, and stone to mine and no signs it has ever been mined before humans means that there was no widespread dinosaur technological civilization.

Re:Its...

[Guy Harris]

Or maybe they're hoping there's intelligent life somewhere up in space because there's bugger all down here on earth.

Re:Its...

[drinkypoo]

In space, a snail can exceed the speed of sound.

They can on earth, too, but more effort (and apparatus) may be required.

Re: Its...

[silentcoder]

So your examples of deep-time resilient technology ... are both less than a century old. Dinosaurs could have had more than 8000 years of our technology without either of those existing !
If we had lasted a mere century less than we have neither would have.
Not to mention it is utterly silly to assume that another species in a different environment would have similar technologies to us. The challenges they would wish to face and resources to apply would be massively different.
Is a wheel even useful to a quadroped that has never seen anything he considered "heavy" ?

Re:Its...

[William Baric]

No, calling it a "Dark Age" is not wrong. Compared to the Greek and Roman civilization it was clearly a regression. No idea why you try to deny reality.

You say we only have progress since 1870? Maybe you should Google "The Renaissance".

As for saying the Dark Ages and the Middle Ages are not the same, this is debatable. Traditionally, the Dark Ages and the Middle Ages meant the same period of time. It's only recently that some scholars decided to limit the Dark Ages to the 5th to 10th century.

Lastly, there is certainly a correlation between religion and regression. It's difficult to know if it's regression which causes the rise of religions or if it's the rise of religions which cause regression, but the link is undeniable. One thing is for sure, during the Renaissance, Christianity did hinder progress.

Re: Its...

[silentcoder]

In a hundred milion years your limepit could be burried beneath a mountain the size of the Andez...
At that timeframe continental drift is a grand prix event. Continental plates colliding. Billions of tons of magma flowed, earthquakes, volcanoes and meteor strikes.

Do you know what a volcanic superplume is.. do you think anything manmade would be remotely distinguishable after one of those ?
All across the entire surface of this planet lies a layer of clay with a unique cadmium signature. That was our first piece of evidence that the K/T event was a meteor... one giant rock collision covered this entire planet in a layer of clay.

Most likely we only even know of about 1 millionth of the dinosaurs that existed. The rest left no shred. We know a few thousand species from a period of 350 million years where the earth had 4 major animal kingdoms. What if a species of mosasaur had reached the point if asking what the purpose of life is ? Mosasaurs were acquatic. Their cities would have layn on long resurfaced bottoms of oceans that are now the tops pf mountain ranges and covered by the sands of deserts.

Look what we did in a mere hundred thousand years... and imagime the possobilities that could lie burried in 4 billion years... and be a little more humble.

Re:Its...

[BitZtream]

Actually your exactly backwards. Space is not empty, it's just not very dense, there are particles out there however.

So it's EXTREMELY low pressure, which means the speed of sound goes up, WAY up.

Just because popular science for people to lazy to care tell you that space "is a vacuum" doesn't mean it actually is.

Space has sound, just not one your ears are capable of hearing before your blood boils away in them.

Re:Its...

[rahultyagi]

I think you have completely misunderstood the scale of time dilation. you really should do the math! Time dilation doesn't matter at all at the orbital speeds of planets that we are talking about, and the gravity wells aren't deep enough either for any realistic configuration of habitable planets (there is a reason "Interstellar" had to put that planet in orbit around a supermassive black hole)

Re: Its...

[vux984]

"are both less than a century old"

I gave 3 examples. But yes all 3 are less than a century old yes.

Although I'd expect platinum jewelry and cut diamonds and other stones (even without laser engraving) would survive just fine... and we've had that for a decent while now.

"Not to mention it is utterly silly to assume that another species in a different environment would have similar technologies to us"

I didn't assume that. I was merely arguing that humanity should leave ample traces that will last 100M years. I wasn't making an argument about dinosaurs.

Re: Its...

[silentcoder]

Platinum jewelry vs 100m years of volcanoes... my money is on the forces of geology over more time than the entire existence of mammals.

Were talking about the age of the himalayas here.

Re: Its...

[silentcoder]

On a human timeframe sure it does not matter. On geological timescales... tiny differences add up to huge effects. Thats literally the whole point of chaos theory.

Re:Its...

[HornWumpus]

If there were intelligent dinosaurs they would have had to deal with sewage to prevent disease.

In their efforts to deal with sewage they would have discovered porcelain. It's simply the best material to make toilets out of.

Porcelain is stable for geologic timescales. Assuming a large population of intelligent dinosaurs, there would be toilets in the fossil record.

Re: Its...

[luis_a_espinal]

You've never taken any undergraduate science classes, have you ? At the orbital velocities of planets the effects of time dilation are miniscule.

No, there is no significant (or probably even noticeable) time differences between Mercury and Uranus.

My thoughts exactly. When I saw the OP's comment about time dilation between planets around the same start, I'm like WTF?

Re:Its...

[HornWumpus]

Persians were very much into math and science, Arabs not so much.

Islam taking over Persia was a historic disaster.

Re:Its...

[silentcoder]

It doesn't MATTER if things are stable or not when they are likely to be buried beneath mountains, or at the bottom of what is now oceans. Not to mention your fundamental assumption is utterly unfounded. At the same time as the dinosaurs three other major animal kingdoms existed. Icthyosaurs, Mosasaurs and Pterosaurs - none of which lived on land. One was airborn and the other were both acquatic. In either case the issue of sewage would require entirely different solutions to anything we've done.

People seriously do not understand just how mysterious deep time really is. The simple truth is that we have no idea what the world was like when dinosaurs lived. We have NO idea. We have a lot of educated guesses, and for every theory at least two major competing theories that fit the tiny, tiny bits of evidence we have just as well - and no way to pick between them while KNOWING that all of them likely have nothing in common with what ACTUALLY happened since it's virtually inconceivable we could possibly have ever imagined the reality - and that's just about tiny, narrow little areas.

What was life like ? What was the world like ? We have basically no idea and we certainly cannot imagine it as we have absolute no context to imagine it. For most of the dinosaurs existence there was only one continent on earth... how did that affect climates ? How did it affect weather ? How did it affect the creatures living ? And how did they affect it and each other ?

Right now India is crashing into Eurasia raising up the Himalayas - where will it be in a hundred million years ? Will it smash it's remaining energy into a fell swoop that raises them faster than they can erode and lift them to new heights ? Or will it bounce elastically and head the other way and crash into Australia ? Or something we can't even imagine... but just picture that, and tell me you still think toilets would survive. Tiny shards of pottery may make it - but the odds of anything finding them is near zero even if they were looking and even if they did find it they would likely come up with a dozen other explanations because if they are anything like us the concept of any previous species having been intelligent will apparently been utterly unacceptable to their minds.

We have nothing approaching a real view.

And through all this - we know that actual fossilisation is an exceedingly rare event. So rare that we believe we have only ever found fossils for a tiny fraction of the species that ever existed because it's such a billion to one chance for anything to be fossilised that nearly every species would come and go without any fossil actually surviving. It's quite likely that there haven't been enough humans yet for a human fossil to survive us.

Just to give you an idea. Prior to 1998 we were aware of exactly four body plans in the entire animal kingdom. Just four - everything that ever existed was some variety of that. Then we realized that, in a fossil discovered way back in 1905 - was in fact a lot of creatures from long before the dinosaurs, and just in that one site we discovered 20 new body plans that nobody had ever known about before, that apparently left no fossils anywhere else (at least, none that we've found), Twenty entire branches of life for which a single mudslide provided all the evidence they ever even existed. Each of them as different from the others as we are from insects.
How many were NOT present when that mudslide made the Burgess shale ? How many entire KINGDOMS of animals have we never even imagined - yet had lived on this planet ? One single site - which nobody thought was significant for nearly a hundred years multiplied the number of animal kingdoms known to have existed by 5. How many more must the REAL number be ?

We can tell stories of evolution for that which lives, and that which we have enough fossils for. We can't be sure how accurate those stories are (but most paleontologists are fairly certain they are more likely than not to be way off).
Walkring with dinosaurs was a fairy tal

Re:Its...

[HornWumpus]

They would be buried, along with the bones that we do find.

If there had been a successful intelligent dinosaur, we would find the toilets. Millions of intelligent creatures would require millions of toilets.

You long argument could also be used to claim that we would never find any fossils, at all. Clearly any single find had low odds, but their is a large numerator in play as well.

Re:Its...

[roca]

You should do some more reading.

Europe suffered a massive setback in the first millenium AD, but it wasn't a religious issue, it was the fall of the Roman Empire. Trade, law and order collapsed and took centuries to recover. Many books and much knowledge was lost. Where were books copied and knowledge most often preserved? Monasteries!

Edward Gibbon blames Christianity for the collapse of the Roman Empire, but I don't think that's what most people have in mind when blaming Christianity for the Dark Ages, and his thesis is not popular today.

Christian institutions sometimes did bad things that held back progress. But in other ways Christianity also fostered progress. It's incredibly important to remember that Europe != the world, and that in the second millenium AD Christian Europe opened up a huge scientific lead over every other culture in the world.

Re: Its...

[vux984]

Platinum jewelry vs 100m years of volcanoes

Why do you think there is going to be a bunch of volcanoes going off everywhere? Some places sure. 100 million years from now there'll be whole new mountain ranges somewhere.

Other places ... not.

Several mountain ranges are upwards of a 2 and even 3 billion years old.

As much as some parts of the world will change in 100M years, other parts will be extremely stable. What do you think the Appalachian mountains looked like 100M years ago? Pretty much the same as they do now.

Something buried deep in a mine in the appalacians... isn't going to be affected much by 100M years worth of volcanoes going on somewhere else.

Re:Its...

[drsmithy]

What do you think someone from a thousand years ago would think of a smartphone ?

Re:Its...

[vux984]

Diamonds degrade and oxidize. They can even burn, smoulder, melt, or simply lose their structure over time at human-livable pressures and temperatures.

Yes all true. While under other conditions they can last a billion years.

There is no such thing as a fire proof safe.

Your point? I'm not suggesting we actually put it in a fire. I'm suggesting it finds itself stuck in an airtight watertight space for a few 10s of millions of years. Precisely where it won't oxidize.

There are very few places 65 million years is stable enough to not crush your experiment

What experiment? I'm not trying to place something for 100M years. I'm looking instead at the odds that something of our creation will randomly find itself in one of those "very few places" and get preserved through chance rather than by design. The entire human race is the experiment.

Even if everything was in a perfectly sealed bunker on the moon it would still happen.

And yet, chance gives us perfectly preserved trilobite fossiles half a billion years old. But.. but... rocks erode... rain, water, even wind... will weather away a mountain.... yet the fossils still exist. We have lizards trapped in amber that are 100M years old.

Some of the diamonds will be crushed. others melted, others dissolved or turned to graphite... but some won't. Some will find some inert stable corner of the world away from heat and light and water and wind. And they'll just sit there.

Could I tell you where to put something so that it would reliably survive 100M years? Nope. But can you credibly tell me nothing survives that long... of course not. We have all kinds of 100M year old traces of even the most fragile biological systems that found somewhere stable enough to ride out the years so we could find them. Insects in Amber for example. You think a lego minifig wouldn't hold up in amber?

That skepticism should be applied to yourself before criticizing others.

That skepticism was about the scale of gravitational time dilation effects... what did you think it was about?

Re:Its...

[angel'o'sphere]

No, calling it a "Dark Age" is not wrong. Compared to the Greek and Roman civilization it was clearly a regression. No idea why you try to deny reality.
I don't deny anything.
I fixed his wrong usage of words, that is all.
Historians use the term "Dark Ages" for times about which we have not written history. As I said before: get it or leave it. The term "Dark Ages" has nothing to do with the rise or fall of civilizations or "technologies".

You say we only have progress since 1870? Maybe you should Google "The Renaissance".
We were obviously talking about technology. Not about philosophy or humanity.

Traditionally, the Dark Ages and the Middle Ages meant the same period of time.
No they did not. No idea where you get that from. E.g. what about the time around 1500 BCE to 1000 BCE? It is a Dark Age, too. Why? simple: because the written history about it got lost, or is very rare: https://en.wikipedia.org/wiki/...

Should I make a list of great things that were discovered or "done" during the middle ages? Do you even know when they started and ended? Simple example: Spain would be a desert if the Arabs had not cultivated it and build up the irrigation systems after the Romans basically deforested it. Oh, yeah, that involves the religion of the conquerors. However: at that time Spain was peaceful. As long as you followed a "book religion" you were protected by the same laws. That changed drastically when the Christians overtook Spain. That basically was at the end of the middle ages, btw.

It's difficult to know if it's regression which causes the rise of religions or if it's the rise of religions which cause regression, but the link is undeniable.
There was no rise of religions. The people already were very religious. They simply switched from what ever religion they had to Christianity (in Europe) and Islam (in the Orient and Asia).

Or do you really think Christianity/Islam was spread to atheists?

And the reason why they switched was mainly military success of the conquerers and the preaching. Suppose you are a Viking and get told: no you don't have to die on the battle field to get into heaven, you only need to confess and pray. Wow: that is easy, isn't it? Especially if you don't have to sent your kids into battle just to hope they go to heaven.

Again: my point was the incorrect usage of the term "Dark Ages".

About the "progress" - or lack there off - I have no opinion, except that it is likely more influenced by slavery, bond slaves etc. than by anything else.

Re:Its...

[ceoyoyo]

"Historians use the term "Dark Ages" for times about which we have not written history. "

You're incorrect: https://en.wikipedia.org/wiki/...

Re:Its...

[ceoyoyo]

The Dark Ages refer to a period of European history, but other regions have all had their dark ages too. The fall of the Mayan empire, various political catastrophes that befell China, the conquering of golden age Arabia by the Mongols, etc.

Civilization has been more of a two steps forward, two steps back enterprise until fairly recently (maybe).

Re:Its...

[William Baric]

It's your usage of the term Dark Ages which is wrong. I find it strange that you gave a Wikipedia link to the "Sea Peoples" to support your point about Dark Ages, and yet didn't look at wikipedia page for "Dark Ages". I'll give you the first two sentences:

Dark Ages is a term of historical periodization traditionally meaning the Middle Ages. It emphasizes the demographic, cultural and economic deterioration that supposedly occurred in Western Europe following the decline of the Roman Empire.

As for the Renaissance, it was also the start of important scientific and technological progress. Haven't you heard of people like Newton, Kepler, Galileo, da Vinci, or hundreds of hundreds of others? Really?

Anyway, it seems obvious to me you are trying to defend religion to a point of absurdity. I guess you live in your own "dark ages".

Re: Its...

[silentcoder]

Except for being buried under a 60-mile layer of ash...

A hundred-million years is quite enough for several volcanic superplumes to occur. Just one of those entirely resurfaced the Russian Steppes once - an area rather bigger than North America. Simple random distribution means that, on a long enough timeline, everything gets altered a great deal.

The longer the timeline, the less the odds that something recognisable is found.

Re:Its...

[silentcoder]

That's just it - millions aren't enough to guarantee anything. Most species never left any fossils.

This is a genuine case of absence of evidence decidedly not being evidence of absence. You should read some Jack Cohen books - he is, after all, an expert in the field you're claiming to know more about than him.

Re: Its...

[vux984]

As I replied elsewhere in the thread... we've got 500 million old trilobite fossils, and mosquitos and lizards in amber from 100 million years ago.

All it will take to prove humans had technology 100M years from now is some piece of modern garbage -- to leave its imprint in some mud somewhere to become part of the fossil record, or get encased in amber, or get otherwise sealed away somewhere where it won't erode or corrode, somewhere dry, somewhere cold, somewhere airtight, somewhere in darkness. It will happen.

The longer the timeline, the less the odds that something recognisable is found.

A yet we have fossile records of soft creatures from half a billion years ago. I can't say we will definitely leave a trace... but you can't definitively say there won't be one either.

Hell... even just a landfill full of e-waste... even if its completely "disintegrated" and the elements compressed and formed into a layer of rock ... just the presence of all those elements, metals, rare-earths all jumbled together; in higher density than surrounding areas... all localized in one spot in one layer of the geological record ... with no natural explanation for how or why they got there ... with odd isotope ratios that all combine to defy natural explanation. Yet 500 meters away in every direction the same layer of rock is perfectly unremarkable.

Re:Its...

[stealth_finger]

Read it again. I didn't pick random times, I picked one big time. When as you say the initial technology of a steam engine has been available, reinvented a few times, and then as you say it wasn't until the late 1800's when it was invented again and then that's the time it took off and spawned everything since. Why did it not do that on any of it's previous iterations? I'm not saying religion was the only cause, but religion is very much anti progress. Not the religions in and of themselves but those who abuse them to keep themselves powerful and rich and the population weak and poor. Obviously there are a ton of different factors at play but you can't ignore that while Europe at least was under religious rule of the vatican, not much progress was made and it was pretty bad for most people. As religion loosened it's vice grip technology started to take off, coincidence?

You drop the middle/dark ages thing. They are the same thing, wiki even says so. https://en.wikipedia.org/wiki/.... Called the dark ages because of all the terrible shit that went on, not because its unknown like fucking dark matter or something.

Re: Its...

[silentcoder]

I never said "definitely". I said very unlikely. Lets say one smartphone is found. What would be seen ? A lump of sillicates, carbon molecules and a few rare earth metals. If one was found by a human a mere 200 years ago it would not be recognized as technology. No serious scientist would propose it for fear of being lumped in with pyramidologists. How long before our children could not be sure if it was technology or just a fluke geological formation ? 1000 years ?
We just had a headline over a sunken city near athens that is now being called "most likely a natural geological formation".
A few thousand years and the line between natural and manmade are already so blurred that archeologists and geologists both believe they are seeing something from their own field.

How long until what is now contemporary technology is so obsolete *we* would struggle to recognize it ? But you are assuming it would be recognizable to a species with an entirely different biological and cultural history ?

Sure we have fossils from half a billion years ago... but for every species we have a fossil off there were probably a trillion species we never knew about or imagined. Its not impossible we would leave a trace - just exceedingly unlikely and that likelihood skyrocketed in the last century . A dinosaur civilization comparable to us im the 19th century at the time they went extinct could easilly have left no trace for us to find. What would somebody discern about 20th century earth if they found a few random fossils ? An elephant tooth and a pig's shinbone. Two from one century would already be extraordinary since the average rate of fossilization is estimated at one individual organism (out of everything alive) every 10 million years (and many believe that figure is optimistic).

Re:Its...

[DarthVain]

Not really. We've moved forward.

The Concorde was a massive failure. It was never economically viable. It cost too much to operate, and could carry too few passengers. Also its sonic booms were not conducive to an urban environment. If you look at the current trend, it is towards increased capacity, while maintaining speed.

The SR-71 really only had two advantages. One was speed, the other was the high cruising altitude. This made it pretty impossible to intercept. However, you are flying a pilot (probably illegally) over foreign airspace. There has been plenty of examples of failure and embarrassment. It was a spy plane that took pictures, it had no arms, nor did it serve any other purpose. With the advent of better satellite imagery (and more satellites) and drones, why bother. Sure the SR-71 was pretty cool, but it was also expensive as well. Anyway it just doesn't make sense anymore.

Re:Its...

[drinkypoo]

In space, sound doesn't propagate, so not even a snail can exceed the speed of sound. The statement is a not even wrong.

Yes, but if you want anyone to read your comment, you're going to have to be funnier than that.

Re:Its...

[Rakarra]

Transistors? Just application of known physics

Most "inventions" could be boiled down to that. There aren't any, and never were, enormous EUREKA! moments that changed the world. It's always been incremental change over time building off of things we already know.

Re: Its...

[Rakarra]

No one knows the others exist. They each develop their own new civilizations after the dust settles. Truly believing they are the only survivors. Who do you thinks going to reach who first? Because if you really believe the people in Gaza who are parlyzed by their religion will somehow ditch that religion and start creating tech and worshipping science you are sadly mistaken.

I'm willing to bet on the folks in Gaza over those in Silicon Valley, because those folks actually know how to survive. You're not going to smartphone-app yourself into being a farmer. Silicon Valley has also destroyed ALL of its farmland (it used to be quite fertile and a location known for citrus 100 years ago), so if other areas are "nuked" and uninhabitable, Silicon Valley will fall apart and go extinct very quickly.

Yeah. Definitely bet on the Gazans in that case.

Re:Its...

[Rakarra]

Human society advanced at exactly the pace it was capable of.

It did? Then why was progress rapid from, oh... 400 BC to 200 AD, then civilization backslid for a few hundred years, and there was basically no progress to speak of at all for the next thousand years?

Of course a few of the answers are "The Plague of Justinian," "The Black Death," "Endless wars in Europe," "Endless Wars between Europe and Asia," and yeah, I'll even lump the spread of Islam as a factor, or at least the spread of fundamentalism.

Re: Its...

[vux984]

Its not impossible we would leave a trace - just exceedingly unlikely and that likelihood skyrocketed in the last century

I'm going to disagree on the "exceedingly" part of the exceedingly unlikely, but overall I think we agree. Every other species has literally had to die 'just-so' with its eminently bio-degradable body in just the right circumstances to leave a trace. Primitive humans are so much easier to to spot because even without bodies they moved the earth around, and left artifacts of pottery and metal, and shaped stone arrowheads, etc.

Modern humanity ... is going to leave a lot more behind, and jumbled together in ways that nothing else ever has. A freight train parked in a tunnel, collapses over time... and its hard to imagine what that's going to leave behind. Mere thousands years it might easily still be recognizeable as a train, and even some of its cargo recoverable. Millions of years out... if water isn't running through it, if air isn't running through it... if it just gets slowly crushed... you are still going to have this half mile line of rust, iron, magnesium, that defies explanation. And it'll take is one plastic switch or length of wire, bit of metal -- perhaps an engine part trapped with some oil... that gets trapped "just so".

As you said, the odds we leave trace behind has skyrocketed. I think that's all i'm saying too. No gaurantee we're still discoverable 100M years out... but if i had to pick a species as having odds of leaving traces that are discovered 100M years out... i'd say humans hands down.

They might not find a human skeleton... but they're likely going to know something was here.

Re:Its...

[Triklyn]

geosynchonous is only on the human timescale. they've still got boosters to adjust their path even now.

Re: Its...

[Triklyn]

we've found dinosaur fossils. dinosaur footprints.

the question really is, how quickly did mankind create something more resilient to the ravages of time than their own bodily remains?

we're also closer in time to the T-Rex than the T-Rex is to the stegosaurus. it's not like dinosaurs didn't have a shit ton of time to get stuff done.

Re:Its...

[HornWumpus]

Toilets wouldn't have to fossilize though.

You can't prove a negative. But if there was a successful, technological, intelligent species of dinosaurs they would have left signs.

Re: Its...

[silentcoder]

>it's not like dinosaurs didn't have a shit ton of time to get stuff done.

That's rather my point. The thing is - for the vast majority of humanity's time on earth WE did nothing that we would recognize as technology today. Wooden bows don't preserve, fire doesn't preserve. It wasn't until we started making stone tools that we built anything that was recognizable later - and that was only about 10-thousand years ago.
The only recognizably intelligent thing we did before that is draw on rocks and that is hardly something with a million year lifespan. I just think that the more than 350 million years where every land animal larger than a small dog was a dinosaur and their close relatives the icthyosaurs, mosasaurs and pterosaurs ruled the skies and the oceans - is more than enough time for something at least smart as us to have evolved and maybe even got some pretty advanced technology done before leaving the place again. Any technology they had would likely have born very little resemblance to ours - after all it would be intended to solve different problems for a different species in a radically different environment - but to assume nothing is just pushing credulity. If velociraptors had taken to keeping some smaller dinos in pens and farming them - how would we know ? If mosasaurs had taken to farming some early ancestor of kelp - what evidence would that leave ?

And considering that would be on par with us just before Mesopotamia (a geological blink of an eye ago - and less than 1% of the time they had) would that not be impressive enough ?

Re:Its...

[silentcoder]

>But if there was a successful, technological, intelligent species of dinosaurs they would have left signs.

You're assuming we would
1) Find the signs
2) Recognise the signs

Whenever a scientists says "there is no evidence of" you should always ask him three questions:
1) Did anybody look ?
2) If they did - would they expect to find anything ? (sorry - scientists are human and expectations influence what they see)
3) If they did find it, would they dare consider that it means what you think it means ?

Again I say, you're making unsupportable assumptions. In a completely different environment it's highly likely that any technology would have born zero resemblence to what we developed. Dinosaurs didn't look like us, they didn't live in a world like ours - if one developed tools to live better, those tools would be intended for purposes we can't begin to imagine, and designed for use by creatures we are nothing like. What would dinosaur tools even look like ?
For most of our existence our tools were made of wood and bone, we didn't even get to stone until the equivalent of about 30 seconds ago. And there is no doubt we were a technologically advanced species even when our most advanced technology was the bow and arrow.

Just consider this - there are absolutely no stone tools whatsoever in China. None has ever been found. Yet China was settled by descendants of people who made stone tools - they damn sure knew how. Did they LOSE their toolmaking ability ? Of course not, we know they didn't since the Chinese were pretty technologically advanced when the west rediscovered them.
So what happened ? One word: bamboo. China had a resource the west didn't have, that could do almost anything stone (and even early iron) could do - with a great deal less effort. I've seen a man throw a bamboo spear through a car door. That stuff is fantastic. But it's also completely biodegradable. It left very little traces. We only found any because the settlement of china is geologically speaking yesterday.

The resources available, the shape of the bodies that need to use the tools, the problems presented by the environment all radically influence what sorts of technology a culture would come up with - it's silly to assume that we would even be able to recognize a dinosaur tool if we found one. Especially if you consider the likelihood that such a creature may have existed closer to the end than the beginning of the dinosaur reign and thus likely met their end most abruptly with the K/T event. They could have been anywhere along a line that took us 90-thousand years without ever sharpening a stone.

Re:Its...

[angel'o'sphere]

The boosters are for aiming or other slight adjustments.
There is no way that a satellite 36000km above earth is crashing as in "diving down and wrecking on earth". They stay there for ever, just like the moon.
As soon as you have no drag from rests of our atmosphere you stay up for ever. That is likely already at 1000km hight.

Re:Its...

[angel'o'sphere]

Why did it not do that on any of it's previous iterations?
We don't know. But if you have an idea, tell us :D

You drop the middle/dark ages thing. They are the same thing, wiki even says so.
Yes, because it is written by people like you, who don't know the meaning :D of the word.

Called the dark ages because of all the terrible shit that went on,
Then name a list of ten things :D I doubt you find more than 4 which happened at random times and not over a course of 1000 years.

In the middle ages we had thriving literature, art and music, to name three things. Later architecture, glass manufacturing, mining etc. Explorations, the bill of rights, progress in ship crafting, european wide banking networks, free trade empires like "The Hanse".

The middle ages were not "dark ages" in the laymen term of "cruel times". And again: "Dark Age" means something completely different anyway.

Re:Its...

[angel'o'sphere]

Anyway, it seems obvious to me you are trying to defend religion to a point of absurdity.
Erm ... could you please find a citation of my posts where I defended religion?

I'm an Atheist, you idiot.

Dark Ages is a term of historical periodization traditionally meaning the Middle Ages. It emphasizes the demographic, cultural and economic deterioration that supposedly occurred in Western Europe following the decline of the Roman Empire.
And this is plain wrong. Some idiot wrote that into Wikipedia. Not my fault or problem.

As for the Renaissance, it was also the start of important scientific and technological progress.
Yes, we all know that. Hence the name. So what is your point?

Haven't you heard of people like Newton, Kepler, Galileo, da Vinci, or hundreds of hundreds of others? Really?
Haven't you heard about: Walter von der Vogelweide, Der von Kürenberg, Dietmar von Aist, Thomas of Aquinas? Or Johannes Gutenberg, Albrecht Duerrer, Hildegard von Bingen, Hans Fugger, Goetz von Berlichingen, ?

Or inventions like the Kogge, Windmills? Reading glasses? The fork?

https://en.wikipedia.org/wiki/...

Sorry, the term "Dark Ages" as synonymous for the Middle ages is wrong in all accounts. It does not even matter if laymen mix it up, or if you want to talk about a general decline. The general decline in Europe after the Roman Empire broke down was due to the turmoil of the wars brought into Europe by the "emigration of nations" or "invasion of the barbarians", we germans have a much better term for it: "migration of nations".

You might want to call those wars "Dark Ages" ... however that is not what the term, as historians use it, does mean.

So from 400 - 600 everything was in turmoil because people like the Goth, the Huns and later the Vikings (just random examples) invaded Europe constantly over a course of nearly 500 years. (Or before that, Kimbers, Teutons, Vandals) And the "Dark Ages" of the Middle Ages are exactly that period: from roughly 500 to roughly 800: we don't know much about it. All famous people we know basically lived before that period (e.g. Attila the Hun/Etzel, about 450, and Karl the great, 800). Plenty of history in between simply got lost. Only really great people still are known, like the Emporers and a few of their vassals.

Forget your stupid Hollywood idea of how live was in the Middle Ages. If we talk about "Middle Ages" people mainly mean Europe. Europe is big, really big. It was everywhere different. When Italy flourished, Poland was still 300 years backward. And the "Dark Ages" the _really dark ages_, that was the periods of the plague and the 30 years war and world war II, the nazi reign, or this: https://en.wikipedia.org/wiki/...

If you want to have an idea why "there was no progress" (actually there was, but you and your GP don't know about it, because you are to _uneducated_) http://www.kondratieff.net/#!t...

Re:Its...

[angel'o'sphere]

Incorrect is the wikipedia article, as it is written by laymen who mix the meanings up.
Perhaps we find a historian who can rectify the issue :D

The point why I'm nitpicking on this issue is: I was also of the opinion that Dark Ages was a synonymous for Middle Ages until a History Professor enlighted me :D

However the "correct" term we use loosely translates into english as "dark middle ages" and that is a difference to "middle ages" and "dark ages" :D because all three things mean something different.

Re:Its...

[david_thornley]

Compared to Greek and Roman civilization it was pretty dead philosophically. Neither Greeks, Romans, or what you call Dark Age civilization had any reasonable variant of science. However, technology continued to improve. I'm not an expert here, but it doesn't look to me like the advance of technology was particularly slowed, and during parts of it there was a lot of advancement in Muslim areas, which was fed back to Europe.

Re:Its...

[david_thornley]

We're pretty much looking at advancements that affected Europe, since that's where the scientific revolution started. We can leave the Chinese out of this for the most part, since they were pretty isolated. The Arab advancements in what's being called the Dark Ages fed directly into Europe, and so Renaissance Europe had more advanced mathematics to go along with the improved technology

Re:Its...

[david_thornley]

The speed of sound has nothing to do with pressure. It has to do with temperature, since the transmission of anything related to a gas is going to go at the speed of the gas molecules.

Re:Its...

[ceoyoyo]

"Historians use the term "Dark Ages" for times about which we have not written history." - angel'0'sphere

You're contradicting yourself again. As usual. If I'd noticed the username earlier I wouldn't have bothered replying.

Re:Its...

[stealth_finger]

Why did it not do that on any of it's previous iterations? We don't know. But if you have an idea, tell us :D

I did. Not the reason, just one of the bigger ones

You drop the middle/dark ages thing. They are the same thing, wiki even says so. Yes, because it is written by people like you, who don't know the meaning :D of the word.

Dark, like a lot of words, has a lot of meanings. This is one of them

Called the dark ages because of all the terrible shit that went on, Then name a list of ten things :D I doubt you find more than 4 which happened at random times and not over a course of 1000 years.

1.Crusades (we'll count them all as one)
2.Inquisition (again we'll count this as one thing)
3.Numerous religious based wars with Anglo-Spanish and others
4.Witch hunts
5.Burnings at the stake
6.Massive disease epidemics (helped to spread by ignorance as well as lack of good medicines)
7.Massive poverty amongst all but the most elite (I'll admit that is kinda similar to today, but a least we don't have to make bread from acorns and tree bark)
8.Good luck to you if were even accused of a crime and put in prison, or gaol or whatever.
9.As above but accused of heresy?......./shudders
10.And for fun. No forks, so lots of food eaten by hand which when combined with appalling sanitation and hygene is just bad news all around.

In the middle ages we had thriving literature, art and music, to name three things. Later architecture, glass manufacturing, mining etc. Explorations, the bill of rights, progress in ship crafting, european wide banking networks, free trade empires like "The Hanse".

The middle ages were not "dark ages" in the laymen term of "cruel times". And again: "Dark Age" means something completely different anyway.

I never said anything about the literature culture or art or anything else of the period. For sure lots of things of value came out of the period. Just not very much is the way of technology or science. Which isn't to say there was none of those.

The middle ages were not "dark ages" in the laymen term of "cruel times". And again: "Dark Age" means something completely different anyway.

Fucking hell man, forget I even said dark. Bottom line. Medieval times was a sucky one to be alive.

Re:Its...

[Triklyn]

the moon is drifting away from us at like, 4 cm a year.

solar wind does wierd things too.

Re: Its...

[Triklyn]

what are they using to pen in the dinos, and what were they made of?

chopping tools? slicing tools? stone is harder than nail.

i think chipping rocks with other rocks to make primitive knives... is one of those things we're going to find as a technological step in any civilization we'll come across.

cutting things, puncturing things, killing things. rocks are essentially fossils to begin with.

before you make a bow, you really do need something to cut the branch.

also, apparently wikipedia puts recognizable stone tools at the 2.6 mya mark.

Re: Its...

[silentcoder]

We didnt take that step for 90-thousand years. And we didnt take it at all in China where bamboo was available.
Why do you assume any other species would have done something we skipped when it was possible to skip it ?

There are roughly a billion things you can pen an animal with starting from heaps of sand. And of course we farmed crops before we ever penned animals and we would have had no archeological evidence of this fact if we didnt draw pictures and eventually build grainstores ?

Re: Its...

[Triklyn]

what step? 2.6 million years ago we had stone tools. almost before homo sapien came about.

Re: Its...

[silentcoder]

Only in a few small areas. Most humans didn't - and many NEVER had stone tools.

Much like the toilets example elsewhere - it's just not universal. For the vast majority of humans that ever lived a "toilet" was a hole in the ground with a wooden seat above it. Romans had flush toilets - which consisted of a a flowing stream in a canal with seats built over it - usually made of stone. Even today in most of Asia porcelain toilets don't exist - what you have is basically a pit in the floor that you squat over and a tap with water to wash your ass and your hands afterwards.

Re: Its...

[Triklyn]

i'd say you can't have your cake and eat it too.

so the fossil record is incomplete, yet we have evidence of stone tools from 2.6 million years ago. our fossil record from 2.6 million years ago is incomplete to the same degree essentially as our fossil record from 62 million years ago. higher percentage lower percentage, quantitative differences rather than qualitative.

Yet we've found it, we've found it, we've found it.

at some point you've also really gotta define what you mean by technology. because it seems like something of a moving target.

Re: Its...

[silentcoder]

>at some point you've also really gotta define what you mean by technology. because it seems like something of a moving target.

Because it is - and because it's really only a proxy. What you're actually trying to ask is - was there ever a previous species capable of abstract thought, capable of reprogramming the brains they evolved for tasks evolution never considered, capable of asking "why are we here" ? Capable of asking questions about the world ? Capable of abstract communication ? A species that could turn the pattern-matching abilities of the brain on itself and become self-referential as we have ?

But those things don't leave fossils - technology is the only proxy we have that might have. But any species that got that, WOULD become technologically advanced if given enough time. There's just no reason to assume their advanced technology would share a single item with any of our technology and plenty of reasons to consider such a coincidental overlap by far the least likely thing to happen.

Re: Its...

[Triklyn]

given a terrestrial origin, there are only so many paths and tools to increasing survivability. weapons good, fire good, cutting good, pounding good. etc etc.

there's a reason why there's convergence in nature, the eye evolved multiple times multiple ways, flight several ways... what makes you think that there would not be convergence in technological evolution too?

i think the first technological step of any intelligence of terrestrial origin is going to be stone tools. easy, super useful, and terrestrial means you've almost certainly got easy access to materials.

Re: Its...

[silentcoder]

For every universal in nature there are hundreds of parochials. Moreover the analogy does not apply. Evolution throws random events at the environment and sees what works. Technology on the other hand is intentional and designed. The options available are detrmined by both the bodies of the designers (none of the tools humanity has created could be used by a species without opposable thumbs) and the environment you live in (which determines both what resources you have available and which tools would be most useful). A species living in a region with bamboo would likely not develop stone tools because bamboo is more flexible, easier to work with and just as strong - humans didnt develop stone tools where bamboo was available. A species 100 million years ago may well have had access to a resource which, like bamboo in Asia, could meet technological needs for millions of years without being prone to fossilize and which we do not even know existed.

Re: Its...

[Triklyn]

they've found choppers and hand axes in asia. just not more complex stone tools.

Re: Its...

[silentcoder]

Very few and likely not made there but brought along by the first settlers. And, of course, useless unless you have opposable thumbs. Those are no requirement for technology but they are required for ours.
Intelligence is one of evolutions most generic tricks. Its evolved multiple times independently and thats just in extant species. It takes only a tiny advance to go from octopus to human-level intelligence and octopi have been observed using simple tools. From tool-user to tool-maker is no major feat. The hardest part is already over.
There have been life on this planet for at least 3.2 billion years. Look what we have done in a mere 0.01% of that. The suggestion that no other species in all that time could have managed most of the same absolutely beggars belief.

Could they define first what a life is?

[short]

"Frastra In the fire storms of Frastra, they say, life begins at 40,000 degrees." - The Hitchhiker's Guide to the Galaxy

Or

[dohzer]

Or extinct because their suns have died. Either or.

Rarely Evolves??

[Anonymous Coward]

"Even if life does emerge on a planet, it rarely evolves quickly enough to regulate greenhouse gases......"

Rarely? What is the sample size for the statistics?

Re:Rarely Evolves??

[VernonNemitz]

I wonder about that, too, because of data pointing to panspermia. If they are evolved enough to survive interstellar travel, then they might also be evolved enough to help stabilize a planetary ecosystem.

Re:Rarely Evolves??

[Anonymous Coward]

FTS: " most early planetary environments are unstable". They are suggesting that the ecosystem fails to stabilise early, so the planets do not have a stable, habitable environment long enough for intelligent life to evolve in the first place. The title is misleading; they are not suggesting that intelligent life evolved and then became extinct.

Re:Rarely Evolves??

[GrumpySteen]

It's the phrasing used. "[life] rarely evolves quickly enough to regulate greenhouse gases" implies that the origin of life on exoplanets been observed often enough for us to to determine that the probability of it evolving to regulate greenhouse gasses is low. We can't even prove how life began on earth, so we sure as hell can't determine the probability for it occurring and evolving on a planet light years away from us.

Re:Rarely Evolves??

[Anonymous Coward]

Yes, and no. Because if they hypothesize based on nothing substantial, that it was only an hypothesis doesn't give them much more leeway.
GrumpySteen is correct, and they make other statements of that ilk in this summary alone, like: "About four billion years ago, Earth, Venus and Mars may have all been habitable."
Might they? Is there data to base this on? And if there is, why use "may have"?

Re:Rarely Evolves??

[Anonymous Coward]

Exactly. That's why it's just media headline nonsense. Add "researcher" to anything and it sounds like some kind of actual study was done rather than the navel-gazing and guessing like everyone else.

Re:Rarely Evolves??

[pipingguy]

They got a grant for mentioning "greenhouse gases" in the text.

This has been predicted in 1923!

[ctrl-alt-canc]

"In the long run, we are all dead'. - John Maynard Keynes, A Tract on Monetary Reform

Re:This has been predicted in 1923!

[invictusvoyd]

In the long dead, we are all run

Re:This has been predicted in 1923!

[Anonymous Coward]

You forgot the Soviet Russia, no?

Re:This has been predicted in 1923!

[stealth_finger]

You forgot the Soviet Russia, no?

where meme forgets you?

Bill Watterson said it best

[hackertourist]

'Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.'

Re:Bill Watterson said it best

[adam.jimenez]

'Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.'

Which is a much bigger sign that if it did contact us.

Re:Bill Watterson said it best

[Anonymous Coward]

I thought it was because we're made of meat.

So

[goarilla]

Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.

Coupled with the odds of being alive and intelligent at the right time
and putting in the resources to make one noticeable (large laser irradiating the sun, dyson sphere, ...) long enough.
I'm not really that surprised there is yet another plausible factor that makes it hard.

The reason is...

[Diac]

A good theory I read about somewhere is that the reason we can not find evidence is simply to do with technology either other alien cultures at the point in time we are witnessing there systems have not developed the technology that we can detect or they have moved beyond the need to blast everything in the entire em spectrum out to space.

How many years have we been detectable by other races and how many years left until our technology gets efficient enough that any trace of our race gets hidden by been simply cleaner with our em pollution.

Will we cease to exist to other races out there when we become undetectable?

Re:The reason is...

[l0n3s0m3phr34k]

Looking at our own "ability" to "regulate greenhouse gases", we just might "cease to exist" too. Technically, another civilization would have to be within 130 light-years of us to pick up on our radio signals. Those signals have actually been tamped down recently with the rise in fiber optics...aliens might be able to detect "life" here by spectrographic analysis of our atmosphere, especially if their within 200 light years they might see an unnatural rise of CO2 from the use of coal and the beginning of the Industrial Revolution. But, there aren't very many stars within that radius we think might have any life, much less an advanced technological civilization.

As for the Fermi issue, IMHO radio signals just degrade too quickly across the vast distances for us to pick up currently (if ever). Even if the theoretical Alcubierre warp drive actually works, it's still only 10x the speed of light. In Star Trek terms, that's just a little over warp 2. Fermi was talking about a time period of millions of years though.

Re: The reason is...

[Opportunist]

So... Earth is like a huge intergalactic crapper?

Re:The reason is...

[angel'o'sphere]

But, there aren't very many stars within that radius we think might have any life, much less an advanced technological civilization.

The 50 closest stars are in a sphere of 16ly: https://en.wikipedia.org/wiki/...

G-Stars, stars similar to our sun in the 100ly spehre are 143: http://www.solstation.com/star...

The total amount of stars in 100ly around our sun is a few thousand stars. Probably all with 5 - 15 planets.

Even if the theoretical Alcubierre warp drive actually works,
Of course it works.
We only don't know how to build one and if we had one we would not know how to power it ...

Re:The reason is...

[blind biker]

That is not a theory, that's a hypothesis.

You would think that on Slashdot people would know the difference.

Re:The reason is...

[Raenex]

A good theory I read about somewhere is that the reason we can not find evidence is simply to do with technology either other alien cultures at the point in time we are witnessing there systems have not developed the technology that we can detect or they have moved beyond the need to blast everything in the entire em spectrum out to space.

The Fermi Paradox goes beyond just detecting communication. They should be here because they would have had plenty of time to spread throughout the galaxy. The linked Wikipedia page includes many possible explanations, including the one you mentioned.

Re: The reason is...

[misanthropic.mofo]

So... Earth is like a huge intergalactic crapper?

It sure is. There are approximately seven billion specimens that prove this fact.

Re: The reason is...

[Opportunist]

Kinda explains the state it's in...

Any chance we could get a lavatory attendant?

Re:The reason is...

[l0n3s0m3phr34k]

Well, then, I don't think a radar signal is modulated in any way to distinguish it easily as an "artificially created signal". But, if you were looking at the source, it would be really weird to see a pulsar-style signal coming from a G-type star lol.

Re:The reason is...

[l0n3s0m3phr34k]

I looked around for an actual number on the "200 light years" and couldn't find anything. However, I found a calculation hereof 14,600 stars within 100 light years based on calculations from here. BUT this is just a calculation based off average galactic density and not an actual catalog and seems way too high to be accurate. Many astronomers think that F stars might have habitable planets, and the K and M type would work as well...although there is an issue with habitable planets near K and M might be tidally locked so that could really screw up the planet's weather. K and M types also have periodic radiation outbursts; with their planets being closer that would also be bad for life.

Re: The reason is...

[l0n3s0m3phr34k]

I didn't say it was a pollutant, just that the rise in CO2 since the start of the Industrial Revolution would be noticeable with a spectrographic survey and would stand out. It would mean that the planet either had some massive volcanic activity, some other as-of-yet unknown geological outgassing, or atmospheric modification via lifeforms (ie us burning coal, or maybe a weird bacterial bloom that decomposes / lets off massive CO2)

Universe teeming with O'Neil Colonies

[pepsikid]

They can be built around any reasonably stable star (especially very long-lived red dwarfs) which has some rubble to rebuild into spacious habitations. No need to seek a proper star or habitable/terraformable planet. No need to genetically warp ourselves or live in underground tunnels like morlocks. The Colonies provide the perfect living conditions for the builder species.

Communication networks are likely via line-of-sight laser or some means we can't comprehend, so there's no transmissions for us to pick up. Hundreds of millions in number around each star, they're still too wispy to show up at distance as much more than asteroid fields or protoplanet belts. Being self-sufficient, it's no big deal when one colony decides to make the long, slow journey to the next uninhabited star. There, they get busy populating the colonies pre-built by robots sent ahead. The universe is old enough that there has been time for every star in the galaxy to be homesteaded by now.

We can get started by dismantling our own moon for material, moving on to Mercury and Mars's moons (planets are too big and unhealthy for our biology) until all of the available floating rock has been utilized. The colonies aren't made of girders and sheet steel. They're built by sintering crushed rock in the beam of focused sunlight, building up the superstructure like a gargantuan 3D printer. To simplify energy collection, the second or third generation of colonies are probably towed close to the sun, to minimize the size of PV panels needed.

Re:Universe teeming with O'Neil Colonies

[drinkypoo]

We can get started by dismantling our own moon for material,

Don't you think we might want to keep it around for tides? Let's just use the asteroids, and maintain the planet as a park or something.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

It will take millions of years to actually dismantle the moon, so Earth and its tidepool crabs are safe in the long run. We need to start with the moon since it's 12 orders of magnitude closer to home than anywhere else. Good practice for a few centuries. Local transportation can be done efficiently through orbital skyhooks. Then, Mercury is next because power is so accessible there. Other moons and asteroids come later since energy would be harder to collect to run operations.

There's not going to be any terraforming of Mars or Venus or living in tunnels or domes because that's the way goblins live, not humans.

Planets will not be mined or lived on permanently, the gravity wells are too deep. Moons will be mined by scooping up surface material and refining them for valuables on-site, and flinging those into orbit via mass driver. The asteroids will be mined by pulling huge bags over them and breaking them all up inside. Other teams will revisit these bags of tailings to use the material for colony building. Mining and colony building will be virtually completely automated.

Re:Universe teeming with O'Neil Colonies

[l0n3s0m3phr34k]

Mars actually needs a much larger moon, to get it's internal dynamo running again. Without a magnetic field, any long-term habitation is not going to work. It needs something like the mass of Vesta in orbit to get it's core churning again.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

We do not need Mars! We only need its moons - as an afterthought, at that. Mars is too light to provide proper gravity, too cold, and atmosphere too thin to protect from radiation and meteors. We cannot and would not want to live there. Ya gotta get your head out of the 1950's scifi assumption of living on alien planets. We have Earth, and we'll have manufactured orbital habitats.

Re:Universe teeming with O'Neil Colonies

[angel'o'sphere]

Without a magnetic field, any long-term habitation is not going to work.
If we would give Mars - by magic - an Earth like atmosphere right now, it would last probably a few 100 million years. By far long enough for a human civilization.

It needs something like the mass of Vesta in orbit to get it's core churning again. That is nonsense. Mars has no molten core as far as we know. No satellite will change that.

Re:Universe teeming with O'Neil Colonies

[angel'o'sphere]

We do not need Mars! We only need its moons - as an afterthought, at that.
The Mars moons are two tiny Asteroids.
You cough and one is slamming you on the back, you fly away and never come back.

No idea how you want to "settle" on such a chunk of sand.

Re:Universe teeming with O'Neil Colonies

[110010001000]

Space nutter detected. Evidence: "Suggests dismantling our moon".

Re:Universe teeming with O'Neil Colonies

[pepsikid]

Of course no one wants to live anywhere that isn't earth-like. There's no other place in the solar system suitable, so we have to build our homes. Please re-read my initial post. As I explained, the moons would be material to build orbital colonies. Crunch up the rock, sinter it into a cylinder shell.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

Well, we cannot summon up gigatons of nitrogen-oxygen atmosphere for Mars, magic or not. And if we somehow organized and funded the many-centuries-long terraforming project to do that, then we still have a hunk of rock that provides too little gravity for our health, and it'll still be cold a.f. with a tiny, dim sun in the sky. Mars is unsuitable for multiple reasons. People like Elon Musk romanticize about "colonizing" Mars simply to engage people's imagination. With so much free-floating material in space, Mars is close to the last place we want to live or try and exploit for resources. Let's spend those centuries building spacious, comfortable orbital communities instead.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

While you're building 'a few superconducing rings around' Mars, and trying to collect enough energy to continuously power it, my tribe will be building hundreds of spacious orbital cities. Enjoy your cold, dry rock and perpetual osteoporosis.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

I... THANKS, man! Yes, I am crazy about space. ;)

Re:Universe teeming with O'Neil Colonies

[pepsikid]

Clarification on "planets are too big and unhealthy for our biology": meaning planet's gravity wells are too dangerous and expensive to get on and off of, and yet *too light* (or too heavy) to provide proper gravity for our biology.

Re:Universe teeming with O'Neil Colonies

[angel'o'sphere]

Well, we can bombard Mars with comets.

And what temperatures and distance to the sun concerns: at the equator the temperature is even right now, with an atmosphere of roughly 1% pressure of earth: 23 degrees centigrade.

As soon as we have something like 40% earth atmosphere pressure, and a high enough oxygen level to compensate for the pressure, the equatorial zones are perfectly habitable.

Especially if you build domed cities there.

Regarding your idea about space habitates, yes that makes sense to and would be "progress" and fun. However your argumentation about Mars etc. is not correct.

Re:Universe teeming with O'Neil Colonies

[pepsikid]

Dude. Enjoy your cold, dry rock and osteoporosis. You'll be able to move in about 10,000 years from now at a cost of 2-3 quadrillion dollars. We'll think fondly of you down there, from our millions of comfortable orbital colonies.

Getting to a technological level is hard.

[Viol8]

Just some of the things that had to happen for us to be where we are now:

1) Life had to evolve
2) Multicelluar life had to evolve (this took a billion years after life itself arose so is probably not a forgone conclusion)
3) Life had to climb out of the oceans (dolphins might be smart but they won't be building any rockets with their flippers anytime soon)
4) Suitable intelligence had to evolve. Had it not been for the asteroid the dinosaurs would still be in charge.
5) Humans had to survive numerous climate changes and if the genetics is to be believed we almost died out and everyone today comes from a very small population who made it.
6) Farming had to be created to allow people to do something other than hunting and gathering.
7) For the industrial revolution plenty of freely available energy had to be lying around near the surface - ie coal. You can't melt iron with wood fires.
8) Someone had to invent radio.

I'm sure there are dozens of other things that could fit inbetween those points but my basic point is that a technological civilisation than can broadcast information out from his own planey is very VERY unlikely. IMO we could well be the only one surrounded by planets full of the equivalents of bacteria and jellyfish but little more.

Re:Getting to a technological level is hard.

[Anonymous Coward]

Step 2 may not be needed. Maybe you can have an intelligent giant single cell organism that can build radios.

Re:Getting to a technological level is hard.

[TheRaven64]

You can't melt iron with wood fires

Not in its raw form, however you can make charcoal from wood (burn it with insufficient oxygen) and then use that to smelt iron. The requirement is concentration of energy, but once you have one energy source then eventually you can concentrate it. You can smelt iron in a solar furnace too, though you need to make a lot of glass to a fairly high standard to do it.

IMO we could well be the only one surrounded by planets full of the equivalents of bacteria and jellyfish but little more.

The point of TFA is that this is unlikely. Without photosynthesis, early life here would have experienced a run-away greenhouse effect and died out. Without the right balance after photosynthesis evolved, the oxygen content of the air would have become high enough to kill off all life. The climate of a planet that is capable of supporting live (enough free energy for evolution, not so much that complex molecules break down) is an unstable equilibrium and it's very easy to push it over the edge into one or other extreme.

Re:Getting to a technological level is hard.

[drinkypoo]

Without the right balance after photosynthesis evolved, the oxygen content of the air would have become high enough to kill off all life.

No. Absolutely not. It would have become high enough to kill off most life. Developing photosynthesis is the hard part. After that, there's a lot more organic matter to work with, and a lot more can happen. Something will mutate to adapt to the new conditions, which are not uniform across the globe.

Re:Getting to a technological level is hard.

[l0n3s0m3phr34k]

You also need a large moon to stabilize the planet's axis, keep the core churning, etc.

Re:Getting to a technological level is hard.

[t0rkm3]

4.) Dinosaurs may have evolved into sentient bipeds had they not been taken out. Had sentience begun where the dinosaurs left off rather than being rebooted into mammalian evolution we might have gotten to self-induced nuclear destruction or grey goo meltdown earlier.

Re:Getting to a technological level is hard.

[Viol8]

They might have done, but they didn't manage it in 200m years and their descendents the birds haven't managed it since (ok crows, but even they're no Einsteins) so I don't think they genetically had what it takes.

Re:Getting to a technological level is hard.

[Viol8]

"however you can make charcoal from wood (burn it with insufficient oxygen) and then use that to smelt iron. "

Yes, fair point. However there simply weren't enough trees around to do it - even in tudor times entire forests had to be grown just for ship wood - which is why the industrial revolution didn't really get going until mass coal production started.

Re:Getting to a technological level is hard.

[argStyopa]

Except by that measure, we too are fantastically unlikely.
Humans are made up of hundreds of millions of specialized cells which, in the scant 3-ish billion years since prokaryotes showed up, had to learn to cooperate synergistically. And "learn" in a non-deterministic sense: basically they had to mutate (randomly) into combinations (randomly) and then be stressed (randomly) such that their offspring would demonstrate a competitive advantage...to the order of a hundred million cooperating.

If you think about that, alone, it's staggering that it happened in that SHORT a time.

Re:Getting to a technological level is hard.

[AthanasiusKircher]

Just some of the things that had to happen for us to be where we are now:

This is an interesting list, and as you note, there are all sorts of "other things that could fit in between those points."

However, your conclusion CANNOT follow, i.e., a technological civilization that can broadcast information is "very VERY unlikely." You have no basis to say it is "unlikely" nor "likely," because we have one data point -- Earth. One cannot extrapolate from one data point.

And that's why articles like this one always bug me a bit. "Researchers Say the Aliens Are Silent Because They Are Extinct." First of all, even the name "researchers" is problematic for a topic like this. What research did they do? Look at Earth's history. What other examples of evolution of life did they study??... oh wait, we know of none, so they didn't have anything else to study.

A better way of viewing this research would be as a continual improvement of understanding the complex history of Earth and life's interaction with the planet. Claiming that this relates in any way to arguments about aliens makes a bunch of currently unsupportable assumptions. Just because Carl Sagan imagined life must be everywhere and common because the universe is just so darn big is NOT a scientific argument.

For example, take the first item on parent's list: "1) Life had to evolve." We have no freakin' clue how easy or hard it may be for abiogenesis to occur. We did some experiments starting back in the 1950s that showed under conditions that may have been like early Earth, we can get amino acids and other similar molecules. That's a LONG way from even the simplest "life form" we can imagine. And there are lots of elements of complexity theory from the past couple decades that have sought to show how complex systems could self-organize, but again most of this is speculative -- and again we just have no clue how "likely" or "unlikely" all of the steps might be.

It could be that if you have a planet in a "Goldilocks zone" with roughly the right mixture of elements and roughly the right amount of water or whatever that abiogenesis happens 90% of the time over a billion years. OR, it could be that there are all sorts of little factors that really have to come together to make it work -- maybe if the temperature is 20 degrees hotter or cooler, the reactions become a billion times less likely. Maybe if some element in the mixture is off by 0.1%, the reactions become a billion times less likely. Maybe if gravity is 10% stronger or weaker, density causes different types of stratification which makes the reactions a billion times less likely. Maybe it wasn't relatively stable conditions over millions of years that led to abiogenesis, but instead one pond over a much shorter period of time that had just the right unusual mixture.

We just have no clue. And the typical response I usually hear is, "Well, but you are simply not considering how freakin' HUGE the universe is -- how many galaxies, stars, planets, etc. The chances that we're alone are miniscule!!!"

Except none of that matters. The only thing that matters is the probability of intelligent life evolving. Maybe that's 90% of the Goldilocks planets. Maybe it's 1 in 100 trillion of the Goldilocks planets, because of all sorts of factors we haven't quantified yet.

Incredibly unlikely events happen every day. If I shuffle a deck of 52 cards, the chances of the particular order I end up with are 1 in 8x10^67. Assuming around 100-200 billion galaxies in the observable universe, and assuming the number of stars in our galaxy in each one, we end up with something like 10^24 stars. Let's assume that on average each of those stars has a planet in the Goldilocks zone (probably overgenerous, but let's run with it). Let's assume a population of 10 billion imaginary aliens on each of those planets, each of whom shuffles a deck of cards every second. Even with all of that, on average those

Re:Getting to a technological level is hard.

[Applehu Akbar]

"Step 2 may not be needed. Maybe you can have an intelligent giant single cell organism that can build radios."

And step 8 is important only for external detectability. It's totally possible for a species to have gone directly to fiber.

Re:Getting to a technological level is hard.

[T.E.D.]

Everything in your list from 3 on is just our path, not necessarily the one and only path for intelligent life. Add to that the fact that there are hundreds of billions of stars, with possibly up to a trillion planets in our galaxy alone, and there are more than one and a half million of those in the observable universe. In that many attempts the odds of more that one success seem to be pretty damn good.

Re:Getting to a technological level is hard.

[Opportunist]

All it takes is the right kind of evolutionary stress until civilization can take over. And, as odd as this may sound, religion. It's the only sensible way you can make more than 10 people work together without a strong cultural history in legal proceedings.

Re:Getting to a technological level is hard.

[angel'o'sphere]

You also need a large moon to stabilize the planet's axis, keep the core churning, etc.
No, you don't. Which physical principle would demand that?

Re:Getting to a technological level is hard.

[TheRaven64]

You're right, though I think that focussing on smelting iron is misleading. If that were the only limitation, then the industrial revolution would just have happened over a longer timescale. It's interesting that you bring up the Tudors, as charcoal production in the 16th century for iron smelting led to laws being passed to prevent deforestation in the UK, so it was possible to produce relatively large quantities of iron with only wood as the energy source.

Steam engines were the big consumers of coal. You can run steam engines on wood, but the density isn't high enough for it to be worthwhile - you quickly spend far more energy moving the fuel around than you get to do useful work. Again, producing charcoal near the forests would have helped with this, but would likely not have produced enough to justify railways, so you'd have ended up with charcoal-powered stationary steam engines fed by charcoal delivered by horse-drawn canal boats.

Perhaps more interesting is Aluminium. A number of sets of crown jewels contain small aluminium objects because it was one of the rarest metals given the huge energy cost in smelting. It would be completely impossible to produce the kinds of quantities of aluminium needed for most late 20th century technology without something far more energy-dense than wood.

That said, a civilisation evolving under such constraints might go straight to electricity generation from other sources. Copper is relatively easy to smelt (easier than iron and quite possible using wood without producing charcoal first), so wires for transmission and winding generator coils would have been possible. Wind turbines are easy to produce given copper wire and some wood and canvas. It seems backwards to us, but it isn't completely implausible.

In fact, looking at when the battery and steam engine were both first invented, it seems quite odd that our industrial revolution followed the timescale and path that it did. It took a lot of changes in attitudes as well as energy availability. Remember that Babbage and Watt's lives overlapped by 30 years, yet Babbage's engines were largely regarded as interesting experiments rather than useful machines (other than using the simpler designs for producing more accurate artillery tables).

Re:Getting to a technological level is hard.

[TheRaven64]

Except by that measure, we too are fantastically unlikely.

Who's to say that we're not? Just because something happens once, doesn't mean that it's not unlikely. See the anthropic principle.

Re:Getting to a technological level is hard.

[Viol8]

"Wind turbines are easy to produce given copper wire and some wood and canvas. It seems backwards to us, but it isn't completely implausible."

But to build a transmission network you need vehicles powered by something so transport the materials and move the earth. Would be very hard to do just with horses. Could have ended up with local wind powered village generators however I suppose.

"yet Babbage's engines were largely regarded as interesting experiments rather than useful machines"

Computers are all about accuracy and fast calculation. If there's limited use for that in a low tech society then computers won't be seen as much use.

TBH even up until the 70s computers weren't seen as mass market devices. It took until they were cheap enough and available enough to allow kids with imagination and ideas to get hold of them before the computer revolution took off. Not something that could have happened with a Difference engine. Though if it had it would be interesting to speculate on how history would have been different!

Re:Getting to a technological level is hard.

[Viol8]

"Everything in your list from 3 on is just our path,"

Well I did state that in my first sentence. The point however is that a lot of statistically unlikely events had to happen for a technological civilsation to arise. The fact that we have one and we're here is essentially a fluke.

Re:Getting to a technological level is hard.

[blackanvil]

"You can't melt iron with wood fires." Actually, the first fuels used to smelt iron and other metals was wood -- charcoal to be precise. Still used by hobbyists and re-enactors who want to recreate the iron available to the earliest smiths. A lot of forests have been chopped down over the centuries to make iron.

Re:Getting to a technological level is hard.

[swb]

It also seems like an equally significant contribution to an industrial revolution is the right mix of sociopolitical and economic conditions.

The Romans had impressive engineering abilities and you would have thought that steam power would have been a natural extension, but it never developed. Their general macroeconomy was grown through conquest and the political and social organization was in many ways built around the military forces that enabled it, not around private firms, hired labor and the other concepts necessary for the kind of industrial development that drives technological innovation.

They also had a large supply of slave labor, which meant that labor saving devices weren't as important or valuable, especially when you factor in that slaves are probably more useful than basic machines in many ways because they have human intelligence -- maybe more like an android workforce.

I've always found it kind of interesting to what-if history if the industrial revolution hadn't happened not because of scientific knowledge but because social and political conditions didn't favor the circumstances of industrial development in a market economy. We might still be living in 19th century conditions without the benefit of the technological advancement provided by widespread industrialization.

Re:Getting to a technological level is hard.

[T.E.D.]

The thing is, its not really. That's a bit of a fallacy. If you try often enough, you logically should see all kinds of "statistically unlikely" things happen. Roll dice enough, and you will see a run of 10 6's in a row, event though the odds against that on 10 rolls are something on the order of millions to one. Try something millions of trillions of times, and damn near anything that's possible (and clearly its possible or we wouldn't be here) should happen multiple times.

Re:Getting to a technological level is hard.

[l0n3s0m3phr34k]

#5, axial tilt

"The gravitational push-pull of the Moon on iron deep inside Earth keeps it hot and molten"

This is why Mar's axial tilt wobbling is so extreme.

Re:Getting to a technological level is hard.

[angel'o'sphere]

Both statements are wrong, or Venus would have strange tilts, too and not a molten core.

Mars is very small, ... just barely bigger than the moon. Both have cooled down because of size, not because of the lack of a big moon.

What keeps earth core molten is radioactive decay. Not the moon. In a few million or billion years the earth core will be solid, too. Regardless of our moon.

Re:Getting to a technological level is hard.

[MrSteveSD]

7) For the industrial revolution plenty of freely available energy had to be lying around near the surface - ie coal. You can't melt iron with wood fires.

And we only had coal because when trees first appeared, there happened to be nothing around that could digest them, so they just piled up, got buried and eventually became coal. However, it's not a complete show stopper since you can make charcoal from wood which does burn hot enough for melting iron.

Re:Getting to a technological level is hard.

[l0n3s0m3phr34k]

Venus is tidally locked to the Sun, and it rotates the opposite direction of all the other planets. Theory is a major impact did this; so that puts comparing it's tilt to Earth and Mars non-comparative. And there is considerable theories that radioactive decay is not enough to explain the total core heat; both radioactive decay AND tidal frictional forces add together. And there is a large difference between "million or billion"; current estimates are that our core won't cool off until long after the Sun is a white dwarf. The axial tilt idea has been verified by hundreds of computer simulations and has been known about for at least few decades now. The core frictional dynamics is far more contested, though.

And their not "statements", but links to sites. If you have a spare $39.99 you can go read the actual paper. Like I said, this is still controversial and even the paper says "we suggest" and "we propose". But as for the axial tilt, even NASA agrees. So, you should show your math and argue with them and not me.

Re:Getting to a technological level is hard.

[ultranova]

Without the right balance after photosynthesis evolved, the oxygen content of the air would have become high enough to kill off all life.

How could that possibly happen? As rising oxygen level kills off photosynthesising organisms, its production falls, and since free oxygen is reactive and is depleted if not replenished a balance will inevitably develop. After that it's just a matter of learning to tolerate, then utilize it.

Re:Getting to a technological level is hard.

[Talderas]

But it's not "random", is it? It's constrained by the chemistry and physics. Truly random would be like a single cell turning into a couch, or a shovel.

We just need to develop the infinite improbability drive.

Re:Getting to a technological level is hard.

[kheldan]

9) (Future) The human race has to survive all the shenanigans, nonsense, and utter bullshit it keeps inflicting on itself.

Re:Getting to a technological level is hard.

[Viol8]

"Roll dice enough, and you will see a run of 10 6's in a row, "

Thats not necessarily true. Even perfect dice may never give you a certain combination no matter how many times you roll them for no other reason than chance.

"Try something millions of trillions of times,"

There's 200 billion stars in our galaxy. Assuming even all of them have habital planets thats still a tiny number when you work out the likelihood of a technological civilisation.

Re:Getting to a technological level is hard.

[angel'o'sphere]

Theory is a major impact did this; so that puts comparing it's tilt to Earth and Mars non-comparative.
Of course it is. They rotate. (Tilt is irrelevant anyway). The laws of conversation of momentum, or momentum of rotation, are the same for all planets (all things actually).

And there is considerable theories that radioactive decay is not enough to explain the total core heat; both radioactive decay AND tidal frictional forces add together.
If tidal friction would heat the earth core, it would heat everything of the planet. Hence we had no continents but everything was molten. Actually it is the opposite way around. If something is warmed by tidal friction, it is the satellite, not the center of the system, see e.g. Europa and Jupiter.

If there are questions how much the Moon adds then we are talking about 1 or 2 degrees centigrade in comparison with the roughly 1000 degrees centigrade the earth core has.

And there is a large difference between "million or billion"; current estimates are that our core won't cool off until long after the Sun is a white dwarf.
The timescale does not matter. Point is: earth is to big (in comparison with Moon or Mars) to cool down quickly. And in comparison to both it has much more heavy isotopes as in radioactive material.

But as for the axial tilt, even NASA agrees.
NASA "agrees" that the "tilt" is stabilized by the Moon. That does not necessarily make it "unstable" without moon. In a rotating system, like Earth, composed out of layers and layers of molten material of various density: the distribution of mass influences the axis/tilt. In other words, the axis/tilt only shifts when masses suddenly accumulate somewhere. They do that with or without a moon. It might be a little more rare with a moon. Nevertheless Earth flipped upside down a few dozen of times: while it already had the moon. And yes after that: it rotated retrograde, just like Venus does right now. Until it flipped again, of course.

Re:Getting to a technological level is hard.

[l0n3s0m3phr34k]

Can you post some links to some scientific papers about the actual Earth itself flipping around? Not the magnetic poles, but the entire planet itself? There's a huge difference between a pole flip and a physical flip...I did some searches, all I can find is about the magnetic poles and some Bible quotes. I'm assuming you didn't actually read the links I provided that say "The Moon keeps the Earth from wobbling violently as it spins", The moon's gravitational pull may have been key to making Earth a livable planet by moderating the degree of wobble in Earth's axial tilt", and so forth.

When I said unstable, I meant unstable as in the way of massive climate shifting as the Earth turns on it's side, ice caps melt, flood, refreeze, on vastly compressed timescales. Or rather, that's what all the research points to. The article about frictional forces has some actual numbers about the cooling that would have happened with the moon; you should read the links instead of just dismissing the science.

Re:Getting to a technological level is hard.

[bingoUV]

And, as odd as this may sound, religion. It's the only sensible way you can make more than 10 people work together without a strong cultural history in legal proceedings.

No, that is only required to make more than a Dunbar number of people work together. Upto 100-200 people can work cooperatively without much sabotaging , just due to the design of human anatomy itself.

Law was required only once more than 200 people started living together - and is less required even today in many small somewhat-isolated villages and completely not required in the many tribes.

Dunbar number is estimated to be in thousands for some fish. Ants work together so well so that the whole hive can be thought of as a living being. You might call all these employ some sort of religion to achieve this - but that would really stretch the definition of the word "religion".

Re:Getting to a technological level is hard.

[TheRaven64]

Because not all life is killed by the direct effects. Some is killed because it can't handle the high oxygen content. Then, the high oxygen content will cause fires. With enough combustable material, these may continue to burn until there's then not enough oxygen left for the remaining life (which has adapted for a very high oxygen content in the atmosphere to avoid dying out already) to survive.

Re:Getting to a technological level is hard.

[drinkypoo]

On Earth this is known as the "Great Oxygenation Event" or "Oxygen Catastrophe". It probably killed most life on the planet.

Right, but again, it doesn't kill all life. It doesn't even have the potential to kill all life, because of the inherent unevenness of a planet. High peaks, low valleys, shallow water, deep water. It's just part of the normal process of life beginning... probably

Re:Getting to a technological level is hard.

[houghi]

This is talking about a humanoid alien, nothing about an intelligent alien. I could see an inteligent octopus that has the ability to make and use tools in a world without any land.

And as long as we do not find it (or it find us) we can only guess what the rules are. For all I knew, we are the least inteligent BECAUSE of all of this.

Re:Getting to a technological level is hard.

[T.E.D.]

Thats not necessarily true.

Prob-stat fail here. Yes, it is nessecarily true. If its truly random, then any possible result will happen given an infinite number of allowed attempts. That's basic Prob-stat. So if those dice are fair, you will eventually come up with 10 6's in a row if you can just keep rolling that long. This is why the house always wins in the long run, even when the odds are nearly even. They have more money than you, so they can just wait you out until you get a bad run.

And all you have to do to see where I got that number is read back in the thread. I know reading referenced material is discouraged here, but try it. 200 billion stars * multiple planets per star (= around a trillion) * the amount of galaxies in the known universe (1.5 million) = millions of trillions of tries.

Re:Getting to a technological level is hard.

[T.E.D.]

Smartest reply I got right here. Thank you.

For viol8 to positively assert that we're a fluke is rather presumptive, but so is your response. FWIW, we aren't seeing any other jackpot winners yet

I'd say technically this is quite correct. What I'm falling back on here in my engineering experience. Particularly debugging. If something happens once, (say your program causes your entire computer to crash). Then yes, its quite possible that the cause of this even was something that is so unlikely that it will never ever happen again, not to you and not to any other user. Its possible the bug was caused by a stray cosmic ray hitting just the wrong bit at the wrong time, and that one bug will never happen again. However, every time in my life I've told myself that, I've been wrong. Maybe the bug is somewhat rare, but computers are so fast and users are so plentiful that even rare things happen a lot. So the safe money is always on it not being a one-off.

I'm seeing the same thing here. It obviously happened once, because we are here. We know of about 8-15 other places (the other planets in our Solar System, however you define planets) where it didn't, but that's all we really know. Now is it possible that its actually so rare that this is the only place out of millions of trillions of likely planets in the universe that it ever happened in? Sure, its possible. But that's not the way to bet.

Re:Getting to a technological level is hard.

[ultranova]

Then, the high oxygen content will cause fires. With enough combustable material,

All potentially combustible material is floating in the oceans, since life has yet to reach the land at this point, because an ozone layer which filters out UV radiation can't form until atmosphere has a high oxygen content, because ozone is made from atmospheric oxygen.

these may continue to burn until there's then not enough oxygen left for the remaining life (which has adapted for a very high oxygen content in the atmosphere to avoid dying out already) to survive.

Adapting to high oxygen content isn't the same as depending on it. Furthermore, a fire will deplete oxygen locally and go out while the global oxygen levels are only slightly affected by a single forest fire event. So what happens is that the increasing oxygen content causes more fires, which increase oxygen consumption until a balance is reached.

This and other reasons

[joh]

I think there are two other points to consider: First, life and even intelligent life does not necessarily mean technology, or technology at an industrial scale. Maybe just THIS is very, very rare, with civilisations going this way separated by enormous gulfs of time and space. And maybe the universe is full of planets with aliens that have some sophisticated culture, but not at an technological scale that would lead to us being able to detect them.

Then there's the bottleneck of how long a species can sustain a lifestyle of full-scale industrial technology. Without forking out into space as soon as they can resources will be depleted very soon and then it's too late. Either that culture will end then or will (have to) become much more efficient and low-key, which again lowers the chances of us detecting anything.

I mean, one very useful aspect of thinking about this is thinking about what is going on here, not there. How long can we sustain this and what do we have to do to sustain it? Maybe we will learn how things tend to go with industrial-scale technological civilisations very quickly, even if too late...

Re:This and other reasons

[r0kk3rz]

First, life and even intelligent life does not necessarily mean technology, or technology at an industrial scale.

We even have examples of this on Earth, Octopus are clearly intelligent and even use items as tools, and yet they didn't develop education, so that anything an individual Octopus discovers is not passed down as collective knowledge.

So the idea that intelligence means technology or even civilization, is tentative at best

Is this Slashdot...

[ControlsGeek]

Or National Enquirer ?

Someone else

[mailuefterl]

That would make them the first species not wiped out by mankind, but by someone else

Same here with low CO2 levels

[trout007]

Without the industrial revolution CO2 may have continued its decline and eventually become too low to support life. 150ppm seems about the range where some plants start dying. We got to 180 ppm. Digging up an burning coal helped raise this amount back to a sustainable level.

Re: Same here with low CO2 levels

[breakermelvin]

Gaia produced maximum species on a cold planet. Odd that. Maximum biomass requires a warmer planet. Coal burning hominids are fixing that. Wetlife doesn't do starship. Robots don't care, so Von Neumann replicators halt.

Conclusion

[Anonymous Coward]

Global Warming (TM) killed the aliens!

Re:Conclusion

[Opportunist]

Let's agree on something. You get that lovely sea-side estate, I'll settle on the hill over there. If you're right, you have a perfect sea side estate. If I'm right, I get to shoot you if you try to escape drowning.

Deal?

Re:Conclusion

[angel'o'sphere]

And at the rate of climate change at the global scale, mankind will have more than ample time to do so.

If you mean with "mankind" the species. Likely yes.
If you mean with mankind, our civilization as we have it right now, that is meanwhile extremely unlikely.

Re:Conclusion

[Maow]

Global Warming (TM) killed the aliens!

Exactly.

This is just a propaganda piece pushing AGW hysteria.

"OMG! AGW (the alien form of it, anyways) killed all intelligent life in the universe and deniers want us all dead like all life in the universe! They want us all dead!"

I guess what the Church of Anthropomorphic Global Warming cannot reasonably prove with actual science they attempt to propagandize with science fiction straight out of '60s sci-fi TV series plots.

Seems you think you know more about the climate than actual climate scientists.

I notice a distinct lack of data rebutting them in your post, just a bunch of hysterics.

It would be laughable if it weren't simultaneously both dangerous to free and open societies and a sad example of the mass idiocy of a large portion of humanity.

That's exactly what a reasonable person would think... when they read your post.

If the global climate changes mankind will do what mankind does best. Adapt and flourish as it has always done.

Tell that to the majority of species that have ever lived on earth and are now extinct. Also, talk about massive assumptions being made on the basis of gut feeling and wishful thinking. I guess if you're so quick to do that, it explains why you think climate scientists are equally guilty of shoddy reasoning.

But that doesn't accomplish the real goals of global wealth and political power redistribution, so anyone who dares point out such facts are painted as modern day heretics

No, they're painted as idiots and deniers - the science is separate from the proposed solutions and since you don't like the proposed solutions, you decide it's easiest to deny the science.

And they dare call people who question any of it "anti-science deniers" when it is they who are actually anti-science,

Psychological projection.

Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.

Never go full retard, son.

It ain't liberalism that set up the TSA, the surveillance state, nor are they the ones policing the bathrooms and uteruses of the nation.

Re:Conclusion

[Maow]

Seems you think you know more about the climate than actual climate scientists.

News flash, Cupcake!

Nearly all "climate scientists" are self-selected pro-AGW propagandists.

If a scientist doesn't accept AGW fully then they aren't considered qualified to become "climate scientists".

And a biologist that doesn't accept evolution isn't considered qualified to become a "biologist". So what? If they want to dispute evolution or AGW, they're gonna have to do some research and publish some peer-reviewed data.

And if they can't get funding from Exxon, et al. for it, then they obviously haven't got what it takes to do basic research.

There's a Nobel Prize for anyone able to overturn the current knowledge in climate sciences.

And there are other fields that reinforce AGW, from paleo biology, geology, ...

So of course most "climate scientists" agree that AGW is all that is hyped. If they didn't they would not be considered a "climate scientist" but a "science denier" and would also never receive any government grants even if they did make it past the university systems' self-selection filter.

You're projecting your own failings onto an entire field of science. Again.

Also, Exxon can afford to issue far larger grants for research, should they want to. But, since they haven't, that would indicate that even they're not so head-up-ass as to disbelieve climate scientists and instead use(d?) propaganda to further their agenda.

It's a kind of "no true Scotsman" fallacious logic that easily deceives the low-info, emotionally-driven types that have never been taught critical-thinking skills...the same types that are or become SJW special snowflakes. It also functions to maintain a pool of "authorities" to which the pro-AGW wingnuts can use for their "appeal to authority" demagoguery.

Emboldended part relevant to the psychological projection you're dishing out.

Also, "SJW"? Didn't I mention earlier, "never go full retard".

It ain't liberalism that set up the TSA, the surveillance state...

You're partly right, it is Progressives who co-opted the "liberal" moniker after they were thoroughly discredited in the early part of the 20th century. Another news flash, Progressives are in both major political parties, the (D)s having been fully co-opted and the (R)s nearly so.

That is why no matter which party is in power, very little changes and why both parties agree on 90+% of policies.

Holy fuck, talk about "No True Scotsman Fallacy" -- do you even read what you write?

...nor are they the ones policing the bathrooms...

Wait...so issuing directives and passing laws to eliminate bathrooms divided by sex and instead divided by whatever "gender" one feels like at the moment is not "policing bathrooms", but a State passing a law to simply restore the status quo, is? Do you even dictionary, bro?

As far as I'm aware, bathrooms have mostly functionally worked for a rather long time now. It's your side that's decided we suddenly need laws. Laws which are reactionary and actually make the issue worse: says on birth certificate "female" but has looked like a man for a decade, complete with beard -- must use female bathrooms. Stupid people making stupid laws making things worse.

policing the...uteruses of the nation.

So being opposed to a mass eugenics program that kills millions of unborn babies who are overwhelmingly African-American by number and percentage (precisely as Sanger and the KKK wanted) and then sells the murdered babies' parts like an auto salvage yard is "policing uteruses (sic)"? Wow. Just. Wow.

Utter bullshit, emotionally driven "that easily deceives the " and you fell for it. In fact, your fau

We really have no clue

[bloodhawk]

The problem is we don't actually know what to look for. We currently look for worlds where life might be possible that is similar to ours. For all we know the universe is teaming with life but we have no idea how to recognise it as we can't actually get out there and look. It is like looking for a needle in a thousand haystacks when you have no idea what a needle actually looks like or is made of, you could step on it and have no idea you found it.

Communication

[ledow]

We don't even listen out for SOS morse messages any more, and that was only around for a hundred years or so.

Any method of contacting an advanced civilisation isn't going to be listened for for more than a few generations before its obsolete and nobody's on the other end anyway. Like trying to send a fax will be in a few decades, or how pagers are all-but-dead, and how the first generation of mobile phones was largely incompatible with modern standardised SIMs, frequencies, codecs, etc.

I don't know what we're looking for, but chances are we aren't going to find it.

Re:Communication

[angel'o'sphere]

We don't even listen out for SOS morse messages any more, and that was only around for a hundred years or so.

Of course we do. Why do you think otherwise?

Re:Communication

[ledow]

Wikipedia, and also many news stories a few years ago that say exactly that - we no longer monitor analogue frequencies for bare-bones distress signals like Morse.

"Satellite processing from all 121.5 or 243 MHz locators has been discontinued.

Since February 1, 2009, the U.S. Coast Guard only monitors distress signals from emergency position indicating radio beacons that broadcast using digital 406 MHz signals.[2]

Digital 406 MHz models became the only ones approved for use in both commercial and recreational watercraft worldwide on January 1, 2007"

Re:Communication

[angel'o'sphere]

But coastal radio stations still do.

And again: all you say is focused obviously on the US.

Mankind on the other hand is a little bit bigger than that puny small nation in the south of the North American continent.

Here in Germany we monitor morse signal, as it is required by law and safety regulations for naval operations.

However morse code is no longer required or tested for amateur radio.

Digital signals only work when your hardware is working. Morse you can send by simply pressing the microphone switch (obviously not a reliable way).

Re:Communication

[ledow]

Not really.

http://www.independent.co.uk/n...

I'm British myself. We stopped listening a long time ago. Nobody really protested.

Given that vast portions of Morse usage are nothing more than an emergency signal that in most areas of the world won't be heard anyway, only 180 years after we started using it, in practical terms it's dead and means nothing. It's certainly no good as a communications medium any more if we you have to check the map to see if anyone's listening, and it won't be long before NOBODY anywhere is listening.

Re:What was the research based on?

[Anonymous Coward]

There's nothing that would prevent chemistry or physics being different in different regions of the universe.

Drawing general conclusions about life in the universe based on a sample size of 1 is bold to say the least. It's a waste of time and those fake "researchers" are con artists extracting grant money from the naive for writing fantasy stories.

The aliens won't have "technology" because they don't exist, it's that simple. The human form is the basis which the universe reflects. Aliens which are more "advanced" (how?) are something that you can only find in sci fi stories.

Nah.

[sabbede]

If life arises at all, it stands to reason that evolution would take hold and life would either adapt to the environment or adapt the environment to suit it.

No, aliens are silent because of time

[DirkDaring]

Even these researchers don't understand the concept of time on a galactic scale. We've been around for a mere fraction of a second in terms of time scale. We haven't been around long enough for aliens to find us, or us to find them. It's why endeavors like SETI are, well, a waste of time.

Re:No, aliens are silent because of time

[DahGhostfacedFiddlah]

The galactic scale actually helps the pro-alien viewpoint. There are so many billions of planets in the galaxy that we would expect them to spawn life. Many systems in our galaxy are far older than Earth. By the time the Earth was formed, the linked solar system had already had a chance to evolve from accretion disk->Kardashians.

And yet the galactic scale is no impediment to colonization. Assuming a 0.0025*c travel speed, it would take only 50 million years to colonize the galaxy. That's nothing in galactic terms.

So maybe alien life is common, but not a single one of the isolated species decided to expand to the stars. Maybe travel between the stars is somehow impossible, even for machines. Maybe they're extinct or maybe then never existed to begin with. But one thing that doesn't explain the absence of aliens is the vast galactic scale. It's smaller than you think.

Sure, we are special

[LarryLart]

Life is highly resilient/adaptable, earth itself went through at least five mass extension events. It doesn’t seem to be, by any measure, a game of chance.

And maybe they are silent just because they are “silent”

I don’t understand why everyone clings on the medieval assumption that advanced civilization will have a big footprint, which is a lot of noise and waste, or either spread far and wide in the universe like diseases?

If you just observe our own recent technological evolution, we go for smaller, more efficient, highly targeted communication/broadcasting, lower the waste (well not there yet but we are aware). If you just project our own latest technological evolution a few hundred or thousands years in the future, the likelihood is high that we will be under high constrain to become extremely efficient and therefore difficult to be spotted from afar, at least with our current level of technology.

Don't you really mean

[argStyopa]

"Researchers make wild ass fucking guess" because that's pretty much all it is when you have a sample size of one.

In this case I'd assert that the person sitting next to you on the bus has nearly the same chance of being right, so clothing their opinion in the false-authority of calling them researchers is rather misleading.

Totally agree

[Victorytractors]

Its really hard for me to believe in this but i'll do the research on this..

The Fermi "paradox" is bullshit

[Anonymous Coward]

For four billion years, life on Earth was microscopic blobs of goo.

Then 600 million years ago - BAM - complex life emerged pretty much in the blink of an eye.

We have no idea how likely that transition to complex life 600 million years ago was - we have a sample size of ONE.

Now go back an read my first sentence: For four billion years, life on Earth was microscopic blobs of goo.

That four billion years was about half the expected lifetime of the Earth. The probability that complex life evolves may very well be infinitesimally small. WE DON'T KNOW.

Believing the universe must be teeming with intelligence is based on nothing more than faith.

Re:The Fermi "paradox" is bullshit

[Dan1701]

For four billion years, life on Earth was microscopic blobs of goo.

Then 600 million years ago - BAM - complex life emerged pretty much in the blink of an eye.

We have no idea how likely that transition to complex life 600 million years ago was - we have a sample size of ONE.

Now go back an read my first sentence: For four billion years, life on Earth was microscopic blobs of goo.

That four billion years was about half the expected lifetime of the Earth. The probability that complex life evolves may very well be infinitesimally small. WE DON'T KNOW.

Believing the universe must be teeming with intelligence is based on nothing more than faith.

Actually, the odds are worse than that. Mass extinctions have happened with monotonous regularity in the history of the world, and only comparatively recently have life forms evolved with internal skeletons that enabled them to get to be quite big. Insects and arthropods probably don't get big enough to carry large enough brains to become intelligent, but arthropods seem to evolve a lot more easily than do vertebrates.

Even when you look at vertebrates, a tendency to evolve big brains seems to be exclusively a mammal thing. Dinosaurs seem to have been ancestrally warm-blooded, ditto crocodilians and so on, but dinosaurs plot right on the expected brain to body size ratio that reptiles have. Throughout the entire age of dinosaurs there never seems to have been any sort of intelligence arms-race developed. Early in the post-dinosaur age, just such an arms race developed with mammals, forcing quite a lot to become smarter over quite a short period of time.

There's two reasons to doubt the inevitability of intelligence developing on alien worlds. There may well be plenty of life, but life more advanced than bacteria will be rare, and intelligent life vanishingly so.

Re:The Fermi "paradox" is bullshit

[CrimsonAvenger]

Dinosaurs seem to have been ancestrally warm-blooded, ditto crocodilians and so on, but dinosaurs plot right on the expected brain to body size ratio that reptiles have.

You seem to be ignoring absolute brain size here. Especially since small dinosaurs (you know, like parrots) have a brain:body mass ratio considerably larger than humans do (1:12 for small birds, 1:40 for humans).

In any case, brain to body mass ratio is just part of the answer, not a complete picture of the issue of intelligence.

Re:The Fermi "paradox" is bullshit

[beheaderaswp]

You don't even understand what the Fermi Paradox is. It actually supports your argument. Which is a garbage argument.

But the real bullshit? It when pseudo intellectuals try to make sweeping claims based on nothing.

Go crawl back into the dark ages and let the big boys get back to work.

Re:The Fermi "paradox" is bullshit

[jxander]

The Fermi paradox hinges on the fact that our solar system is relatively young, on a galactic scale.

~4billion in the ~13 billion year old Milky Way

If any other planet was even 1% older than us, and evolving on a similar path, they'd have more than enough time to completely colonize the entire Milky Way by now. And that's assuming a mere 1% age difference. The Milky Way has been around for 200% more than our fledgling star.

Re:The Fermi "paradox" is bullshit

[Triklyn]

the immediate benefits of being able to fly because your useless gray matter isn't too heavy, usually outweigh the investment in gray matter that will allow your descendents to fly eventually.

Anthills

[sinij]

Could ants detect signs of human civilization from their ant hill in the forest? Probably not, but this doesn't change the fact that human civilization exists, and side from occasional lawn extermination are largely unconcerned with ants.

We are not contacted because our civilization is likely not at all unique and not at all interesting to entities capable of contacting us.

Re:Anthills

[goose-incarnated]

Could ants detect signs of human civilization from their ant hill in the forest? Probably not, but this doesn't change the fact that human civilization exists, and side from occasional lawn extermination are largely unconcerned with ants. We are not contacted because our civilization is likely not at all unique and not at all interesting to entities capable of contacting us.

We are concerned with ants. We study them. We build ant-farms. We use them in research. If ants were anything close to intelligent enough to express a desire to communicate with us, we'd know. Your analogy is incorrect; *you* may be unconcerned with ants, but humans as a group are.

Re:Anthills

[Areyoukiddingme]

Could ants detect signs of human civilization from their ant hill in the forest? Probably not, but this doesn't change the fact that human civilization exists, and side from occasional lawn extermination are largely unconcerned with ants. We are not contacted because our civilization is likely not at all unique and not at all interesting to entities capable of contacting us.

We are concerned with ants. We study them. We build ant-farms. We use them in research.

Well that explains a few things.

Idle speculation ...

[MacTO]

This sounds an awful lot like the discussion surrounding habitable planets 25 years ago. There really wasn't enough to raise the discourse above idle speculation because we were dealing with a sample of one (the solar system). The situation wasn't much better shortly after the discovery of exoplanets since the sample was incredibly biased.

The situation for planetary atmospheres is similar today. We have an incredibly small sample of planets where we have studied the atmosphere in any detail (again, the solar system) and hints about the atmospheres of a highly biased sample of exoplanets. Give it another decade or two, and maybe we will have a basis to speculate on the habitability of extrasolar planets ... but that certainly isn't the case today.

What's your sample size?

[Oligonicella]

...it rarely evolves quickly enough to regulate greenhouse gases...

If it isn't greater than one, your blowing smoke out your ass.

Pointless and Useless Speculation

[sycodon]

Even if there were advanced civilizations on only 1% of all the planets, that would still be millions or more.

To believe there are no other advanced civilizations out there, that they are somehow obligated to come pay us a visit, or that they blew themselves up, is pretty fucking arrogant of us.

When you move into a new neighborhood and the neighbors don't come to visit you, that doesn't mean they don't exist

Re:Pointless and Useless Speculation

[Yvan256]

When you move into a new neighborhood and the neighbors don't come to visit you, that doesn't mean they don't exist.

Obligatory

Re:Pointless and Useless Speculation

[Opportunist]

Even if we're not, look at our development. Even if another civilization was on par with us, they could not even communicate with us if they wanted.

Whenever the topic gets to alien life forms, everyone assumes that the aliens must be advanced compared to us and have mastered interstellar, maybe even intergalactic, travel. Says who? Who says it's even possible to do this akin to various SciFi movies? What if the aliens would have to use newtonian physics to get here? Even if they developed 20 LJ away their journey would take centuries.

Our development from "duh, me make fire" to "duh, remote control is broken, need new TV" took about 10,000 years. And we're still in no position whatsoever to fly to any other star than our own. Hell, even reaching the next planet is something we've been working on for half a century now. And every time we actually manage to get a non-manned robot there on a one way trip we celebrate it hugely. What makes us think that anyone else in this universe is actually so far ahead of us to be able to fly about between the stars AND have the hubris to assume that someone this advanced would actually want to have anything to do with us?

Re:Pointless and Useless Speculation

[michelcolman]

Or perhaps they all died already. We already came close to mass extinction with nuclear weapons, and technology continues to improve. Once a single fruitcake can 3D-print a bomb big enough to destroy the planet, it's game over. Are we going to last 10,000 years in such unstable conditions?

Re:Pointless and Useless Speculation

[butchersong]

Tools use is fairly common among animals on this planet. Specialization in tools provided such an advantage to us as a species that it is hard for me to believe we would be anywhere near unique especially given the millions of other environments that have life that must be out there.

Re:Pointless and Useless Speculation

[michelcolman]

I would find it hard to believe that there would be lots of lifeforms out there, but none of them would have gotten a tiny headstart on us like, say, 10,000 years or so (which is nothing on a cosmological time scale).

Re:Pointless and Useless Speculation

[CaptainDork]

You're on to something and there's another component:

Of all the life forms on this planet, only one has developed the capability to deliberately fuck with stuff on the planet.

While that makes us unique, it doesn't mean we won't shit in our own mess kit.

I can dig the extinction hypothesis because humans will probably be among the shortest-lived animals on this planet and stuff.

Look at the dinosaurs. They lasted 200 million years and were minding their own business (and not consciously altering shit).

Who here among us seriously entertain the idea that humans can coexist for more than a negligible fraction of that time?

Re:Pointless and Useless Speculation

[ITRambo]

Only the very large dinosaurs are gone. The rest are today's birds.

Re:Pointless and Useless Speculation

[ranton]

Our development from "duh, me make fire" to "duh, remote control is broken, need new TV" took about 10,000 years. And we're still in no position whatsoever to fly to any other star than our own. Hell, even reaching the next planet is something we've been working on for half a century now.

All of the time spans you give here are inconsequential when compared to the age of the universe. Even if it took us 10 million years to go from current technology to quick interstellar travel, if life is not unique to Earth then we are either the first sapient species or the only one. 10 million years is simply not a long time at this scale.

Star systems started forming within a billion years of the big bang (source), over 13 billion years ago, and it took less than 5 billion years for life to reach its current state on Earth since its creation. That leaves over 8 billion years for potential sapient civilizations to emerge before us. One physist claims it would take 5 - 10 billion years to colonize the entire known galaxy even with current propulsion technology.

We may find out life is so rare we are either the only ones or among only a few dozen inhabited planets. But if life is common at all, it is very likely there are intergalactic civilizations which have been around for billions of years. That is what leads many people, myself included, to believe life is an extreme rarity.

What makes us think that anyone else in this universe is actually so far ahead of us to be able to fly about between the stars AND have the hubris to assume that someone this advanced would actually want to have anything to do with us?

We have people on our planet devoting their careers to researching earth worms, so it doesn't take hubris to believe that out of potentially near infinite civilizations there may be some who have scientists interested in studying pre-interstellar civilizations like us.

Re:Pointless and Useless Speculation

[coastwalker]

The elephant in the room is that cosmological distances are unbelievably large. The energy expenditure and sheer material cost of building something that can move any further than the outer reaches of a solar system is so huge as to make almost pointless even if possible. Currently it is blind faith rather than physics that suggests that the human race will ever be able to visit even the nearest star.

What is slightly more puzzling is that if the galaxy is teaming with technological civilizations we can detect no sign of their signals. Though this may just be the inadequacy of current technology. Discriminating against stars for any electromagnetic signal even for a focused laser is probably beyond our means at the moment. I have not seen any analysis of this from people like the SETI institute, has anyone seen this analysis?

Re:Pointless and Useless Speculation

[Anonymous Coward]

If it had only been 10,000 years... There's good evidence that our ancestors in the 'Homo' genus probably made/used fire at least 1,000,000 years ago. Fire allowed us to outsource the energy inefficient processing of food in our stomachs to cooking, that processed food giving us the extra energy to run bigger brains. Fire was inherited by the final version of Homo Sapiens which eventually made it out of Africa and colonised the planet around 60,000 years ago.

So arguably our development from "ugh, ugh, ugh [me made fire]" to "Ignition! [I've got fire coming out of a rocket nozzle]" took easily long enough for the probability of a nearby star going nova, a killer asteroid impacting, or an orbital shift turning us back into Snowball Earth, to be uncomfortably higher than zero.

Re:Pointless and Useless Speculation

[JustAnotherOldGuy]

Even if there were advanced civilizations on only 1% of all the planets, that would still be millions or more.

Exactly. Even if it was 1/100th of a percent we'd be talking millions, if not billions.

-

To believe there are no other advanced civilizations out there, that they are somehow obligated to come pay us a visit, or that they blew themselves up, is pretty fucking arrogant of us.

It's not just arrogant, it's statistically idiotic. The mind-numbing enormity of the numbers involved means that even with extremely pessimistic projections there are almost certainly billions of planets with advanced civilizations in the universe.

Billions of galaxies, with each one of them having billions of potentially life-supporting planets...the suggestion that there's no one else out there is ignorant beyond belief.

Re:Pointless and Useless Speculation

[CaptainDork]

No.

Birds have a definition.

Dinosaurs have another.

Lineage doesn't provide equivalence.

Re:Pointless and Useless Speculation

[slazzy]

Or we could be the first that have evolved enough to communicate. I feel there's a pretty good chance of life out there, even if it's single-cell or similarly evolved.

Re:Pointless and Useless Speculation

[cfalcon]

> ND have the hubris to assume that someone this advanced would actually want to have anything to do with us?

Because it isn't hubris. Humans are interesting. Perhaps not to some rock-being, or whatever space opera alien is in your head that is Sooooooooo advanced that they find us boring, but to SOMETHING at SOME TIME. You posit a pretty strange concept: that if there's a zillion advanced lifeforms out there, that literally NONE of them would find Earth, or humanity, interesting in the slightest. That's the problem: it's trivial to imagine a species "so advanced" that we are very very boring to them. It's much harder to imagine that the universe is EXCLUSIVELY filled with these beings.

Re:Pointless and Useless Speculation

[penguinoid]

Basically, the argument is that aliens are probably not on exactly the same "blink of an eye" as we are. As you noted, from discovering fire to space travel took us only about 10,000 years, or 0.00025% of the time life has existed on our planet. And only the last hundred years or so would have allowed for interstellar communication. So you shouldn't expect more than a 0.0000025% chance that we are able to contact aliens less advanced than us. The chance is further reduced if you assume the more advanced aliens would be more visible (eg galaxy-spanning empire) compared to barely-out-of-the-stone-age aliens.

Re:Pointless and Useless Speculation

[RicktheBrick]

Just suppose that we are living in a computer simulation. Someone designed this simulation to test how intuitive the program would be. Than there would be no aliens to help us since that would be our primary job. Our job is to discover new and better ways to accomplish things. It would not help us to accomplish this if we discovered an alien race since we alone must discover anything new. So it might be true that we are alone in the simulated universe.

Re:Pointless and Useless Speculation

[Opportunist]

Interesting enough to observe? Maybe. Interesting enough to waste time and resources to get to them? What exactly would you say makes us interesting enough to send representatives over the distance of a few to a few hundred light years? Remember, unless we're dealing with a civilization that somehow managed to develop non-newtonian propulsion systems, that would mean being in transit for tens if not hundred of years.

Re:Pointless and Useless Speculation

[JustAnotherOldGuy]

Just suppose that we are living in a computer simulation. .... So it might be true that we are alone in the simulated universe.

And it might be true that when I fart, pigs fly out of my butt in formation playing Tchaikovsky's Violin Concerto in D major on finger cymbals, but so what?

If we're living in a computer simulation then all bets are off, since basically anything could be true or not.

There might also be an alternate mirror universe identical to this one in every single way, except for some guy in Jakarta who is 0.003 millimeters taller than his alternate universe counterpart. And I'm okay with that, frankly.

Re:Pointless and Useless Speculation

[nine-times]

Whenever the topic gets to alien life forms, everyone assumes that the aliens must be advanced compared to us and have mastered interstellar, maybe even intergalactic, travel.

There's an even more fundamental assumption that alien life forms are interested in building technology and speaking with aliens on other planets. Not only do I see no reason to assume that aliens *can* communicate with us or travel to meet us, I don't see any reason to think that they would *want to*. We can start by looking at some of the other intelligent animals on our planet: chimps, dolphins, and octopuses.

Although I'm sure some people would point out the distinction that these animals are not *as smart* as we are, but even taking that for granted, it's not clear that the distinction is really about brainpower. If you could genetically engineer an octopus to have greater brain-power, I'm not sure it would respond by seeking to communicate with other planets. An intelligent being that was, for some reason, unable to see the stars, might never develop theories about space. They might have a dramatically different understanding of life and the universe, which leads them away from the idea of exploring space.

Even within our own species, there are plenty of people who think that trying to communicate with aliens is stupid, that we should throw away our technology and live "closer to nature." I don't think it's unimaginable to think that a very intelligent alien race might generally take this point of view.

Re:Pointless and Useless Speculation

[EllisDees]

1% would be wildly optimistic. Even a millionth of that would be. That's still a shitload of planets, though.

Re:Pointless and Useless Speculation

[EllisDees]

My guess is that life will be fairly common in the universe, but almost all of that life will be of the single celled variety. Just look at the history of life on Earth - for 2.9 billion of the 3.5 billion years that life has existed, that's what it was. Getting over the hump of becoming multicellular is a huge barrier. For most of the remaining 600 million years, life was of the non-intelligent sort. There is no reason to think that it's inevitable. Civilizations are probably extremely rare in the universe, let alone civilizations that don't destroy themselves soon after becoming intelligent.

Re:Pointless and Useless Speculation

[sycodon]

It just occurred to me that I'm pretty fucking arrogant to suggest that we are an "advanced civilization"

Re:Pointless and Useless Speculation

[danlip]

You keep saying non-newtonian, but it's really special relativity that's the problem here - speed of light being an absolute speed limit and energy requirements going up exponentially as you approach c is the issue. If it was just newton's laws you could keep accelerating past c and get there much faster and with less energy.

Re: Pointless and Useless Speculation

[nachtelfjeiu]

What could alien scientists learn from us? They may have studied enough worms and other inferior species to be beyond learning much more from either a worm or our planet.

Re: Pointless and Useless Speculation

[Izuzan]

Except of course. Aliens may not have gone through a dark ages becuse of religion, and lost hundreds of years of technology because of it.

Re:Pointless and Useless Speculation

[HornWumpus]

First generation stars have no heavy elements. Hence first gen solar systems won't have the chemistry for life.

Re:Pointless and Useless Speculation

[JustAnotherOldGuy]

It just occurred to me that I'm pretty fucking arrogant to suggest that we are an "advanced civilization"

Well....we might be advanced, but the problem is that we don't have anything to compare ourselves to so it's difficult to say.

Using a sample size of 1 is bound to give us errors, probably in both directions.

Re: Pointless and Useless Speculation

[jd]

Ish.

The SKA interferometer will be able to directly see a planet's atmosphere at a range of 100 light-years. If two or more gasses are present where they react in each other's presence AND the ratio of those gasses is stable over time, you have concrete proof of life. This cannot be achieved by known (or unknown) natural processes, a dynamically maintained equilibrium that would cease to exist through any process other than direct action requires a biological process.

Actually, it requires at least two. Any organism that tries to make things favourable for itself must necessarily alter some second dynamic to be unfavourable to itself. You cannot do more work without producing more byproducts (conservation of matter) that are in a lower energy state (conservation of energy, since energy has been taken out) where some of these are toxic to the organism (if it wasn't, it would be processed for energy and matter until it was toxic).

So, one organism always produces an instability. Two is the minimum. The more you have, the more stable the dynamic becomes as there are increasingly better solutions to the set of equations. If an organism develops that tries to exploit the equilibrium (which is inevitable), the equilibrium is lost and the new organism is put at a deficit. A new equilibrium will emerge as a result.

This, by the way, falsifies Nash's argument against his equilibrium. The equilibrium is an emergent phenomenon, so if the dynamic changes, the equilibrium changes. Nash made an error by assuming a dynamic equilibrium has to itself be around a static point. No. The dynamic equilibrium has one Strange Attractor per class of actor in the system. That really should have been obvious and I'm honestly shocked Professor Nash did not see this in his original work or his later appraisal.

Now we get onto communication. Could, in principle, a SKA-class array or the half kilometre single dish in China, be used to communicate at a distance of 100 LY to a civilization of like ability?

Much more difficult. The so-called waterhole is the obvious line to use, as there is virtually nothing natural emitting there. Incredibly quiet. Long baseline interferometry can be used to cancel out much of the random noise from individual telescopes, terrestrial sources, etc, as can long timebase interferometry. So you're essentially taking a lot of radio-frequency photos that are, themselves, taken with a very long exposure time. Stuff in common accumulates, stuff that's different cancels out.

A sufficiently slow, pulse-modulated, message at that frequency will be extremely obvious above the noise, even if it's well below noise level any given instant. You're relying on the fact that noise is random, so that the average can be set to zero. The objective is to guarantee that the signal, after sensitivity, loss of strength and less-than-ideal capture time, strictly exceeds zero at the desired distance.

Once the law of big numbers kicks in, noise is not an issue. The average of any number of zeroes is zero. What matters is signal. If the pulse, transmitted for a second, would be 3,600 times too weak, transmitting for an hour would mean that someone capturing for an hour would detect the pulse.

Interferometry means you can also use constructive interference. Even Linux supports nanosecond accuracy and data from nanosecond-accurate PPS sources, and there are atomic clocks now that are millions of times more accurate than the official definition of the second. With that kind of gear, getting the phase such that the waves constructively interfere wherever we want is not going to be difficult. We know the phase difference already, because powerful natural radio sources must be visible from all telescopes and that same accuracy tells us how out of phase they are relative to said source.

Is that enough to go 100 LY, though? Even if both planets were ringed with telescopes, you're limited to less than the shortest year of the two per pulse and one pulse is not enough to say hello. To be unambiguo

Re: Pointless and Useless Speculation

[Zorpheus]

It is not certain if it is possible to travel any faster than we do already though. Science fiction is fiction, don't forget. Also, space travel requires large amounts of energy. I think we can do it now because the technological advancement have us an abundance of available resources. This is temporary though, resources will run out, and humanity will fall back into a fight for survival. This will make space travel a crazy unaffordable luxury.

Re: Pointless and Useless Speculation

[Opportunist]

Religion is a necessity for civilizations. At least for humans. Yes, it sounds odd, but ponder it for a moment.

Human is a pack oriented animal. We work in groups of 5 to 20 individuals. Anything larger than that and the group breaks into subgroups, fractions and sections. Ask any halfway decently sized club. Unless there is a VERY good reason to keep cooperating, groups of such a size will split and they will, and that is the crucial part, work against each other if the benefit of the own group depends on it.

In other words, if you want to create larger groups than this, you need something to keep them together. Most important, you need something to keep them from going against each other.

Not, in today's society, we have a long and strong history of culture that serves this purpose. We have social norms, we have a justice system that is so ingrained into our thinking that we cannot even fathom a world without "justice" (whatever form it may eventually take), we have as a rather new concept things like nations that offer a sense of belonging to something bigger.

Imagine there is no such heritage, no cultural background that teaches you this.

What is your reason to not kill the person who moves in next to you who you don't know at all to get his stereo? Again, imagine no legal system (or at least one that is too weak to effectively prosecute you because your "pack" is as strong as the one you'd oppose), no "moral" system that has been established that tells you killing human beings is wrong and most of all, no system that tells you that you should not kill him because he's just living next to you, he's not related to you but still living in the same country, he's your neighbor. All these things don't exist.

In such a world, it is very hard to get people to cooperate. But if you're someone who wishes to lead a larger group of people, you need a way to get them to cooperate. And, well, back then, the formula was simple: More people equals more power, more power means that not only can we hunt larger animals, we also can steal anyone's prey because we're more.

Conveying such a concept is hard. Especially since the net benefit for the individual is hard to convey. Why should I bend to your will instead of being my own boss? And this is where religion comes in and shines.

Religion is awesome as a power tool. You don't have to promise anything tangible. Because all the rewards come in the afterlife. And people have always been afraid of death. Since times immemorial. Burial rites show us that even the most distant of our ancestors most likely had some sort of afterlife belief. So promising good things in the afterlife if you now heed my commands is something that really further my goals. Not only that, but I don't even have to pay. Ever. Your reward is in the afterlife. And you can't even call my bluff because, hey, how would you know?

Religion is an awesome tool to gain and maintain power over people. And it has been since its invention.

Re:Pointless and Useless Speculation

[Opportunist]

The problem is both. But in the end it doesn't really matter, interstellar travel of living beings take an insane amount of energy or an insane amount of time, and most likely, it would take both.

Re:Pointless and Useless Speculation

[C0R1D4N]

Yet Dinosaurs roamed for 66 million years and there's no signs any of them ever developed tool usage.

Re: Pointless and Useless Speculation

[Izuzan]

And up to a point it is. But the fact the worlds technology level dropped and went backwards in the darkages because of the church.

While it helps keep group cohesion, when it starts to effect other aspects of life, ie education hinderance of science religion needs to be done away with.

Re:Pointless and Useless Speculation

[CaptainDork]

Fuck you.

dinosaur
dnsôr/
noun
plural noun: dinosaurs

        1.
        a fossil reptile of the Mesozoic era, often reaching an enormous size.
        2.
        a person or thing that is outdated or has become obsolete because of failure to adapt to changing circumstances.

bird
brd/
noun
noun: bird; plural noun: birds

        1.
        a warm-blooded egg-laying vertebrate distinguished by the possession of feathers, wings, and a beak and (typically) by being able to fly.
        synonyms: fowl; More
        chick, fledgling, nestling;
        informalfeathered friend, birdie;
        budgie;
        technicalavifauna
        "feeding the birds"
                North Americaninformal
                an aircraft, spacecraft, satellite, or guided missile.
                "the crews worked frantically to ready their birds for flight"
        2.
        informal
        a person of a specified kind or character.
        "I'm a pretty tough old bird"

Re:Pointless and Useless Speculation

[DarthVain]

Moving things physically is practically impossible (without some magic technology) on that scale of distance. Even projecting energy or waves any meaningful distance that are not meaningless is no easy task.

Atmosphere probably does not help either. Also unless using light, things like radio waves are just too slow, and will degrade. Even light, is pretty slow when you start looking at the scales involved, and light, needs to be narrowly focused, in that if it isn't aimed specifically directly at you, you will not be able to receive it. Unless you can control Sun/Stars and build Solar sized Mega Structures... all impossible.

Earlier this year, someone on here when talking about the topic of visiting one of our nearest neighbors did the math as to what a communications laser would have to do in order to keep contact with a spacecraft all the way to the planet in question. It was something spectacular, like having to have it in orbit, with the combined wattage of all our nuclear powered generation on earth, which would have to have some untold focusing and accuracy (not to mention material capacity to not destroy itself) as to not vaporize the thing at the receiving end.

So while the technology isn't quite as "magical" as physical movement at those scales, it is certainly fantastic to say the least. Anyway, with the scales involved I think it is pretty unsurprising that we haven't found anything, nor will we likely.

It is like an ant in New York, travelling to Tokyo, or trying to communicate with another ant there. Sure perhaps he can magically hitchhike a ride somehow, but practically not really possible. Then consider that the scale is less likely New York to Tokyo and more like New York and the Moon....

Re:Pointless and Useless Speculation

[gzuckier]

The elephant in the room is that cosmological distances are unbelievably large. The energy expenditure and sheer material cost of building something that can move any further than the outer reaches of a solar system is so huge as to make almost pointless even if possible. Currently it is blind faith rather than physics that suggests that the human race will ever be able to visit even the nearest star.

What is slightly more puzzling is that if the galaxy is teaming with technological civilizations we can detect no sign of their signals. Though this may just be the inadequacy of current technology. Discriminating against stars for any electromagnetic signal even for a focused laser is probably beyond our means at the moment. I have not seen any analysis of this from people like the SETI institute, has anyone seen this analysis?

maybe they all use spread spectrum.

Re:Pointless and Useless Speculation

[gzuckier]

Basically, the argument is that aliens are probably not on exactly the same "blink of an eye" as we are. As you noted, from discovering fire to space travel took us only about 10,000 years, or 0.00025% of the time life has existed on our planet. And only the last hundred years or so would have allowed for interstellar communication. So you shouldn't expect more than a 0.0000025% chance that we are able to contact aliens less advanced than us. The chance is further reduced if you assume the more advanced aliens would be more visible (eg galaxy-spanning empire) compared to barely-out-of-the-stone-age aliens.

But.... we are getting a pretty wide timeslice of the universe, due to the timelag of distant signals.

Re:Pointless and Useless Speculation

[brantondaveperson]

Even if there were advanced civilizations on only 1% of all the planets, that would still be millions or more.

This is the kind of logic that the marketing department use to justify products. "Even if only 1% of the people in the world buy this, we'll be millionaires, and 1% is hardly any, we can't lose!".

One percent is just as much a plucked-out-of-the-air number as any. There's no particular justification for one percent of planets to host intelligent life, it could just as easily be one millionth of one percent, and then there would be hardly any.

Re:Pointless and Useless Speculation

[stigmerger]

It's not about visiting us, it's about producing detectable signals. To date, none of the presumed-bazillions of extraterrestrial civilizations have (demonstrably) done this. We're speculating on which factors in the Drake Equation might explain this. These folks are arguing that n_e includes no factor for duration, but that maybe n_e is only n_e for a short time, and that therefore f_l and/or f_i are small because evolution takes time. Judging from the evidence, I'd say another plausible explanation is that the variable L is small, because ... well, Malthus was right. I guess that roughly falls under "blew themselves up", but takes it out of the realm of foolishness by suggesting that life is inherently self-limiting if the same features that are required to survive long enough to evolve are also lethal to those that manage to prevail in that struggle.

Then, again, maybe the rules for what constitutes intelligent life are a lot more open than we imagine, and the place is teeming with life we don't know how to detect. Does it always have to evolve? Does it always require "habitable" planets? (Does it always have to produce EM radiation? Do we just need more-sensitive instruments or more time?) Open questions.

Re:Pointless and Useless Speculation

[RockDoctor]

Whenever the topic gets to alien life forms, everyone assumes that the aliens must be advanced compared to us and have mastered interstellar, maybe even intergalactic, travel. Says who?

Evidently all the people you talk to. I tinker around the edges of the exo-life and OOL (origin of life) scientific communities, and few of those people make that assumption.

Our development from "duh, me make fire" to "duh, remote control is broken, need new TV" took about 10,000 years.

The archaeological evidence is that humanoids and fire have been associated for between a half-million and a million years. Our species is only about 200 to 250 kyr old. Whether that means that "mastery of fire" (a phrase to contemplate the next time a fire engine screams past your window at 3 am) is 250 kyr to 750 kyr older than our species, or that "mastery of fire" is a defining characteristic of our species is something to debate.

Within the laws of physics, we can conquer the galaxy in the next Myr or so. Unless we meet someone else (in which case, we conquer a half, a third, a quarter .. of the galaxy Big fucking difference.

Re:Pointless and Useless Speculation

[RockDoctor]

Go home and revise your elementary cladistics. Or leave your parents basement and revise your elementary cladistics.

There's a reason that cladistics have completely replaced previous ways of describing phylogenies. It's because it works, unambiguously. It makes testable predictions.

It also has a jaw-breaking terminology which provides an effective barrier to dilettantes. [SHRUG]

I'm trying to remember when I last edited my signature - 5 years ago, or 10 years ago. I see no reason to edit it. Your incomprehension is not a good reason to edit it.

Re:Pointless and Useless Speculation

[RockDoctor]

You posit a pretty strange concept: that if there's a zillion advanced lifeforms out there, that literally NONE of them would find Earth, or humanity, interesting in the slightest.

Actually, I don't think that's the relevant question. No one I know for one second believes it likely that aliens would come to Earth (or any solar system that has humans in it - today, give or take a megayear) to study humans. "They" may study humans incidentally, as a sideline, while in the process of going somewhere that they consider interesting enough to go for their own purposes. Hell, they may even find us interesting to talk to. Or eat. Or eat while talking to (if you can grok that as being a good thing).

Unless Lt Scott does change the laws of physics, interplanetary travel is going to be a one-way (or less) trip for organic entities, so the first aliens to meet "us" will be going somewhere else, and are vanishingly unlikely to divert, and any subsequent meetings are also going to be of the same fleeting variety (with data from previous meetings sent back to the point of origin, so not "every contact is a First Contact" scenario.

Re:Pointless and Useless Speculation

[RockDoctor]

Even before you approach relativistic velocities (say, 0.1c), the energy requirements are wildly beyond our current technologies. Newtonian mechanics are adequate to prevent interstellar travel (and make solar system travel pretty difficult) until we have at least fission reactors in space. Which requires a slew of technologies we haven't really started on yet - such as environmental management.

Re:Pointless and Useless Speculation

[CaptainDork]

Ignorance is not improved by by lengthy narrative nor faux complexity.

Grab a dictionary. Any dictionary.

Daisy World

[Gim Tom]

Doesn't anyone else remember Lovelock and the Gaia hypothesis? I think his books on Gaia were very popular back in the late 1980's

also

[superwiz]

For live to have a chance, the planet has to have a large body which shields from periodic life-wiping asteroids hitting it. Every crater on the moon was caused by something hitting it which would wipe life on earth if the moon's gravitation didn't pull it in. Because the moon is far enough from earth and rotates quickly around it, it's able to attract most of the asteroids with a stronger gravitational pull than the earth's pull.

End Game

[aAnaRchY]

Or all the Aliens reached the End Game long time ago and we are the few who still try to finish it...

Re:Here's a theory

[pla]

That by the time a species overcomes the various forms of slavery imposed on them, the propaganda that is used to combat science and control them, it's too late and thier world starts killing them as they are finally subjected to an decline in birth rates because they were too stuipid to understand that no engineering can survive long enough to contain the radionuclides that will eventually destroy their own genome.

I can't tell whether I agree or disagree with you, but at least in what I quoted, you have two questionable premises.

First, "slavery" exists as a purely social issue, and has no connection to the long-term viability of a species. You could even go so far as to say that humans still practice slavery, we've just managed to dial it down over time from "because I can" through "conquered" to "tribal" then "racist", and now we've gotten to the point where we (mostly) "only" base our slavery on speciesist boundaries.

And second - The universe has a hell of a lot more radiation than the pittance we've managed to accidentally release into the environment through disasters like Chernobyl or Fukushima, or even through atmospheric nuclear testing. Any biosphere that can't handle a few mSv over baseline every now and again won't survive nature, never mind their own technological disasters.

Re:d;~;b

[Opportunist]

Exploring Earth is a bit like using a toothbrush. Once someone else has done it, you kinda don't wanna do it anymore.

Detect without Visiting

[Roger W Moore]

When you move into a new neighborhood and the neighbors don't come to visit you, that doesn't mean they don't exist

True but usually you can see some signs that there are neighbours there such as hearing their car or the music they are playing. In our case we have not heard anything so either we are not listening in the right way, they make practically no 'noise' or they don't exist at least close by. However I completely agree that detailed, but wild, speculation like this is a waste of time because it adds nothing to the discussion since they provide no firm evidence to support the conjecture.

Re:Detect without Visiting

[ShanghaiBill]

True but usually you can see some signs that there are neighbours there such as hearing their car or the music they are playing. In our case we have not heard anything so either we are not listening in the right way, they make practically no 'noise' or they don't exist at least close by.

When humans first invented radio, we broadcast strong simple signals because our technology was primitive. These signals would be detectable from very long distances away. But we are rapidly moving to much weaker and complex transmissions. This has the benefit of using far less power, and has much greater bandwidth. But it also makes the signal harder to detect and almost indistinguishable from background noise. There was only a 150 year window from when we started to transmit, and when our transmissions became indistinguishable from static. Compared to the age of the Universe, that window was a very tiny blip.

wild, speculation like this is a waste of time

Wasting time on wild speculation is the whole point of Slashdot.

Re:Detect without Visiting

[Firethorn]

Compared to the age of the Universe, that window was a very tiny blip.

And even then, I remember reading a report that if you combined our most sensitive radio with our loudest transmitter in history - the detection distance wouldn't even reach Alpha Centauri.

That means that an alien race would probably have to be both much more interested in listening than we are, and probably more advanced. Certainly willing to put resources into something like a solar system sized interferometer radio array.

If they wanted to transmit loudly enough for us to hear them via the SETI project, dedicating a gigawatt level power plant to the transmitter is a good start, and that assumes that they have some idea that our star, specifically, is ready to listen now.

Evolutionary Timescale not Cosmological

[Roger W Moore]

The universe is still very young by cosmological time scales.

The evolutionary timescale is the one that matters for the development of life and based on our sample of one this seems to be a lot, lot shorter than cosmological timescales although getting to the multi-cellular stage took a while so it is possible we were just lucky.

Re:Evolutionary Timescale not Cosmological

[Roger W Moore]

Since the topic is ostensibly about timescales greater than our civilization, it all matters and your inflammatory preface doesn't make your redundant point well

Actually I thought that the topic was about why we have not detected aliens. Your point about the Universe being young on a cosmological scale would indeed be relevant if the cosmological timescale was comparable to the evolutionary timescale but it isn't which makes your point that the universe is young is irrelevant to the discussion.

I apologise if the logic here escapes you so let me try to explain. If you have a house which is only 3 years old this is young for a house. However if you looked in the garden in summer and found it devoid of all plant life, even weeds, you cannot explain it by saying that this is because the house was young because plants, particularly weeds, grow on a time scale of weeks or months, not years. There would need to be another explanation such as someone regularly praying weed killer.

For the same reason the fact that the universe is young is not a good explanation for the absence of life given that there appears to have been plenty of time for life to evolve multiple times over and so there has to be some other explanation. I can understand how pointing out facts which make your statements irrelevant might annoy you but generally is not considered inflammatory since the comments addressed the argument and were not intended to make you look stupid, you did that all by yourself with the second post although I suppose pointing that out could be considered inflammatory.

Re:Evolutionary Timescale not Cosmological

[Roger W Moore]

It's not a fucking race. It's not like the universe started and automatically life must start springing up instantly. The only fact that we have is that it took us 13 billion years to be here.

Sorry but you are just plain wrong here. It did NOT take us 13 billion years to evolve, it only took us 3.5 billion years. In fact the sun itself only formed 4.5-5 billion years ago from the remnants of a supernova that occurred 6 billion years ago (we know this from the ratio of natural Uranium isotopes found on the earth today). The universe has been around for more than 2.5 times the age of our solar system and almost 4 times as long as it took for us to evolve and there have been stars which have been created, burned for billions of years and even died before our sun formed.

Hence all the evidence we have suggests that life evolves, or at least can evolve, on far shorter timescales than the age of the universe so far. This is the heart of the Fermi paradox. Why does it seem that no intelligent life exists anywhere else except the Earth? It's not a race for life to evolve but simply an almost statistical certainty given our current understanding.

Yes it is possible that we have everything understood perfectly and that it just happens that the billions to one odds came up and we are the only life in the galaxy but we would need a lot more evidence before anyone starts to believe it. Given our current level of knowledge it is far, far more probable that we are missing something and so the question is what? This could be that life is common but intelligent life is incredibly rare; it could be that we lack the technology to detect advanced races; it could be that interstellar travel is impossible etc. However it CANNOT be that the universe has a lot longer to life. The problem we are faced with is why there is no intelligent life NOW when our best understanding is that there should be lots. The fact that intelligent life may evolve again later in no way helps solve the problem with the apparent lack of intelligent life now.

Re:Evolutionary Timescale not Cosmological

[Roger W Moore]

Not only did my post clearly show that the solar system come from earlier stars (in fact it even told you how old the preceding supernova was!) it also pointed out that because there were preceding stars and the timescale for evolution is short (relatively) this is why we would expect life to have evolved.

The fact that you still don't grasp the concepts involved and are unable to post any sort of question or fact rebutting the argument means that either you are just being stupid and trolling or that you are not intelligent enough to grasp the concepts and not willing to try. My money is on the later since you seem genuinely incapable of comprehending the argument so sorry but I really can't think of a way to explain it any simpler so you can understand it.

Re:Evolutionary Timescale not Cosmological

[Roger W Moore]

Which dismisses the fact that we COULD NOT exist if the universe hadn't been here for 13 billion years.

Why? Science works on evidence and reasoned argument not just because you think it ought to act that way. There is absolutely no scientific evidence to support this claim which means that it is NOT a fact. You can call me silly names until you are blue in the face but this just makes you look like an idiot who is trying to win a scientific argument based on force of character rather than force of evidence and that never works.

Here is why you are wrong. The star which went supernova leaving the material from which the solar system formed had a lifespan measured in millions, not billions of years. Hence all the events directly leading up to us evolving took place in a little over 6 billion years. Had the solar system formed from the debris of one of the first supernovae we could have evolved ~6-7 billion years earlier. If that's wrong please provide a reasoned, scientific argument as to why because the scientific community would love to know where this chain of events is flawed because that would help solve the Fermi paradox. Your own personal opinion of what you want to be true is irrelevant to how the universe actually works. That's a tough lesson to learn but one that science is good at teaching - you should try it some time.

Effing GREENHOUSE GASES?!?!?

[RogueWarrior65]

Unbelievable amount of anthropomorphism going on here. Did they speak English too? Try watching a little less Star Trek.

A non-traditional response to the FP

[SkyLeach]

Consider this: particle physics shows us that entangled observation (not to be confused with human or intelligent observation) ties past and future events together into a causative vector of influence.

Extrapolating from this using entangled observation similar to Einstein-Rosen bridges between quantum events suggests (mathematically) that there is a correlation between frames of references in real-space once a chain of events is initiated.

This would have the effect of linking independent causative frames such that the 'arrow of time' would diverge, probabilistically, between relative frames.

Or, attempting to explain this analogically:

The light from a distant star contains a tremendous amount of observable information about a star, and a limited amount of information about exoplanets (Doppler shift, chronographic direct imaging, etc...). As technology advances, however, it should be possible to tease out (observe) direct evidence of extrasolar life from this meager data due changes over time to how life changes a planetary atmosphere (specific to biome, but similar divergence vectors).

Depending on how one interprets causative entangled observation, this could actually have a strong anthropic effect on life. Evidence that alien life, intelligent or not, exists on an exoplanet would strongly influence the actions of any intelligent species towards visiting and exploring the planet. This would be very close to a strong motivational influence towards any intelligent social network, yielding a high probability outcome of events.

Depending on distance between planets and assuming that technological development is generally rapid, there becomes a high probability chance that any technological species would, inadvertently, directly affect the development (probably adversely) of all emergent evolutionary biomes within observational range.

As a species matures, they would probably realize this at some point, and take one of two divergent vectors: Some level of apathy (no empathy, just settle habitable planets or destroy competition) or avoidance (let them develop, don't interfere). Extrapolating those two motivational vectors, it's likely that there are those that would visit for nefarious reasons, and likely that there are those that would seek to prevent that type of interference due to social morays based on the above principles.

Uh oh..

[NettiWelho]

Posting to undo mod.

Pretty much what Baxter hypothesized

[blind biker]

This is pretty much what Baxter hypothesized in Manifold: Space - an excellent hard sci-fi novel.

WTF?

[NetNed]

This isn't a story on aliens. This is a story on greenhouse gases and some guy that I am sure will want funding to study "regulating" it. Thinly veiled native advertising for his cause.

What about other solvents?

[oldcarsmell]

It has been theorized that organisms based on solvents other than water may exist. These may be able to exist on planets outside of the goldilocks zone. Why aren't we expanding our search?

Extremely Useful Speculation

[FeelGood314]

This is a very important area of study and will tell us a lot about our future.

There are 4 broad possibilities:
1) The galaxy is teaming with advanced intelligent life and we just can't detect it.
2) There are not many earth like planets
3) On any given earth like planet the probability of intelligent life evolving is extremely small
4) Intelligent life never leaves its home world and doesn't last very long.

4 is looking like the most likely answer to the Fermi's paradox.

1 seems unlikely. If we increase our energy consumption at just 0.1% a year for part of the next million years we would be pretty easy to spot. 2 is looking very unlikely, we see planets everywhere we are able to look. If 3 is also incorrect we had better start being very careful about what we do because the chances of us lasting another couple thousand years would be pretty small.

Re:Extremely Useful Speculation

[SuiteSisterMary]

Pluck a scientist from, say, 1990. Lock him in a room with all sorts of 1990s scientific equipment.

Could he identify and decode somebody making a modern cellular telephone call? Could he identify the encrypted digital signal as not noise? Figure out how to demodulate it? Decrypt it? Then figure out the codec?

Or could he identify standard 2.4 ghz wifi traffic with standard WPA2 encryption? Could he further decode, say, a Netflix stream running across it? Demodulate it, decrypt it, figure out the file format, figure out the codec, figure out the display parameters for a 1080p signal?

What about a scientist from the 1980s? From the 1970s? From the 1960s?

Wow Darwin must have been an idiot.

[joeboomer628]

Successful organisms adapt to the environment or become unsuccessful. The development of feedback systems is a by product of evolution. Most life forms on this little speck of rock have gone extinct, but some are still here evolving our little asses off. People who write studies should read them before publishing.

Habitable? Wait, what?

[CaptainDork]

About four billion years ago, Earth, Venus and Mars may have all been habitable.

That's when they were created.

Things were quite messy back then.

They haven't called because

[pjv936]

they don't talk to babies. The period of time a civilization will use radio is only a few hundred years at most. The period of time a civilization is at the stage where they can relate to us without disrupting our civilization is only a few thousand years. The odds are that there are no other civilization at the right stage within communication distance.

Re:first

[neoritter]

You know, it might be a great idea to make it so the first post has to be a declared user. No ACs for first post.

Re:Here's a theory

[MrKaos]

I can't tell whether I agree or disagree with you,

The point was to test if the statements would be modded into oblivion because it is ugly to look at the reality of our own world. Perhaps I shouldn't have said "nuclear nitwits" but it sounded kind of catchy. What I'm saying is, if there is extinct sentience, maybe they were as stupid as we are and maybe that is the point the researchers are making.

You could even go so far as to say that humans still practice slavery

That is *exactly* the point.

Any biosphere that can't handle a few mSv over baseline every now and again won't survive nature, never mind their own technological disasters.

However this isn't. More like Any species that can't handle a few mSv over baseline persistently won't survive their own technological disasters. Add to that carbon, and all of the pollution from our consumer society it appears we may not be "fit" to survive.

It is our supreme arrogance as human beings that we detach ourselves with our avarice and apathy from the planet that supports us. The biosphere will be just fine and will eventually adapt to all of the artificially produced radionuclides we dump into it.

The question is if humans will survive.

A good reason to avoid interaction ...

[LarryLart]

Every species has its own evolution path. There were many species before us, that at that time looked like the winner, say dinosaurs, what would had happen if other species instead of following their own path will had adopted/copied them?

I think many civilizations, like species, are doomed to “fail” while others will choose a different path and move forward, yet maybe to fail in the a next step. Life if anything is about diversity and walking your own path just a thought.

Terraforming

[sls1j]

So if a planet in the Goldilocks zone is usually destined to freezing or burning up it seems to suggest a path to terraform Venus. We just need to export an organism that can live there and absorb the CO2 and survive the acidic environment. Some set of microbe that already lives on earth perhaps would fit the bill. Something that could float around in the atmosphere where it isn't quite so hot.

Faster than light communication

[Bobbox1980]

Aliens likely have discovered more advanced forms of communication that are faster than light. They wouldn't use radio or other EM spectrum forms of communication and that is probably why we haven't heard anything.

There is NO PARADOX

[scatbomb]

In fact, there is no Paradox. This is exactly what should be expected. The intensity of a radio signal drops off as 1/(distance)^2, this is the inverse square law.

Say you have two antennas, one sitting 1 mile from a 100kW (maximum allowed power for radio in the US) radio broadcast tower and one sitting on a relatively close planet 100 lightyears away. The ratio of the difference in intensity will be 2.9E-30. In other words, only a handful of photons actually reach the antenna placed on the exoplanet, certainly not enough to generate any kind of recognizable signal. THERE IS NO PARADOX. We're simply too far away.

In addition to that, the earth is becoming radio silent as we shift from broadcast towers to low power communication and internet. It's pretty likely aliens would do the same thing, meaning there will be only brief periods of radio emanating from worlds where intelligent life forms. We've only been listening for a couple decades. Pretty unlikely that our period of listening would coincide with an alien world's period of broadcast and that we would actually be close enough to collect any signal.

I submit that there is no paradox here. It's all a consequence of being too far apart, radio signals attenuating (inverse square law), and brief periods of popularity for mass broadcast technologies followed by radio silence as internet/other tech replaces it. Makes total sense.

Re:There is no paradox

[Junta]

Hell, even if we figure out some magic physics, we could be *surrounded* by Star Trek level civilization and still not be able to perceive it easily unless they come directly knocking on our door, even if they aren't trying to hide or anything.

Oh really?

[sootman]

I always figured it was because radio waves get exponentially weaker as distance increases. Or maybe because space is really fucking big and mostly empty. But sure, maybe the aliens are all dead now, too.

Overbreed, overshoot, and collapse.

[Maxo-Texas]

We are in an overshoot scenario now (and have been since the 1980's so it's too late to do anything about).

In the near future, we'll exhaust a lot of industrial metals at the same time. Unless we find replacements for all of them at the same time, the most likely result will be a greatly lowered carrying capacity and much more expensive (and so lower) industrial capacity. It's likely to be combined with civil unrest and a mass die off.

For example, we used as much chromium in 2014 as we did from 1900 to 2000 combined (it's likely to be exhausted at reasonable prices in our lifetime).

Since it's so common for species to overbreed their environments here on earth, I think it's a likely scenario on any other planet as well. I think it would be pretty common for species to hit this wall too hard before they get past it technologically. So the universe may be full of planets with fallen civilizations and a couple billion intelligent beings looking up at but unable to reach the stars.

There is no paradox

[SoftwareArtist]

The "paradox" they're worrying about simply doesn't exist. If you assume the universe is full of intelligent life, you expect to see exactly what we've seen: nothing. The distances involved are just too huge. Barring some major new revelation about the laws of physics, humans are never going to be traveling throughout the galaxy. At best we might send small, unmanned probes to a few nearby stars. There could be thousands of advanced civilizations scattered through our galaxy right now, and we'd have no way of knowing about them. They'd be invisible in the ocean of 100 billion stars, with no way to talk to each other and not much reason to even try.

As Douglas Adams put it: "Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."

Ocean has additional challenge

[aepervius]

In atmosphere you can generate easily exothermic reactions and thus have tools. In ocean you cannot easily maybe some rare hot vent but even those do not go very high in temperature, and without protection I am guessing such a specie would find the contact very painful. So you have a problem of kickstarting the tools. That's why ocean intelligent specie getting out are more like idea ->????->profit : it waves over some intractable problems. In any likelyhood such a specie would have to evolve amphibian or into an oxydant atmosphere (be it oxygen or something else) before even starting with tools.

We never had anything blasting into space

[aepervius]

Our initial signals were mostly omnidirectional , so what we blasted went into 1/r^2 in intensity. Needless to say it did not go beyond a few dozen au before being lower in intensity than random galatic/solar noise in the same frequence. If you were on alpha centauri 4 light years away you would not detect us with a SETI programs. All those "alien caught our tv signal and found us" stories/films are bullshit. The truth is that SETI can only detect intentional signal. And how many such intentional signal have we made ? If I recall correctly at most in the last 40 years about 2 hours directed at M2 or M10 of directional highly powered radio signal. that's it. And that is the only signal somebody elsewhere could detect (and it was highly directional).

"How many years have we been detectable by other races" : Not year, not month, not days : we have sent detectable signal for a few hours about.. The fermi paradox is more that we cannot detect anything but there is a solution to that paradox : we cannot detect anything because it is frigging hard to detect signals or send some. And nobody bothers sending "I am here" due to the cost and the very low probability of getting any answer.

It's the Omega molecule

[slashmydots]

Okay it's not really the Omega molecule from Star Trek Voyager but it's possible that interstellar travel via spacial warping has like a 99% chance of destroying the planet or pushing it out or orbit or something. That or the energy required is so dangerous, it could blow up a planet, which current math suggests is very plausible. So eventually all aliens blow themselves up via common technologies based on similar physics of how the universe works in all cases.

What probabilities tell us

[Tablizer]

It does seem "lucky" that the Earth has remained relatively stable temperature-wise for roughly 4 billion years.

I was always curious about this fact. I generally attributed it to some kind of negative feedback mechanism whereby if it drifts too far in either direction, then a "feedback factor(s)" kicks in to correct it.

But so far no consistent factors(s) have been identified that I know of. The chemistry of Earth's upper layers has changed a few times such that a correction mechanism that works under one chemical configuration often doesn't work well in another. (And life seems to eventually learn to gobble up excess and change things yet again.)

One consistent factor that's been proposed is that if the Earth becomes completely frozen over, water insulates volcanic heat enough that it eventually triggers higher than usual volcanic action, blowing dark, energy-absorbing dust onto the surface, melting the ice.

But, this requires just the right amount of volcanic action: too little and the dust-ice-melt scenario doesn't happen, and too much and we get more mass extinction events.

Civilization may just be rare and we may just have won the cosmic lottery.

It does seem a bit if a coincidence that we are in a smaller-than-normal galactic cluster. The law of averages should put us in a medium or large one (Copernican principle). This suggests a filter of some kind.

It's possible that civilizations form fairly often in large galactic clusters and conquer or absorb any competitors. We may just be too rural to be worth messing with and/or found.

If we had formed in a larger cluster, which statistically we should have, we'd be conquered or absorbed by now and wouldn't be here wondering why we are alone.

Based on this line of speculation, civilizations (C) arise approximately once in small galactic clusters and a few times in larger ones. If C were more common, we'd wouldn't be alone, and if C were less common, we'd be in a larger cluster.

I believe this a natural "statistical" conclusion of the known facts that 1) we are alone, and 2) we are in a small galactic cluster.

(There is still "zoo theory" that aliens keep us protected but hide from us.)

Hooked on TV

[seven of five]

What's to be gained, information-wise, by exploring the wider universe? Once you've figured out the laws of nature, and see they apply everywhere, there's not much point in examining chunks of rock other than the one you're sitting on. Entertainment, on the other hand, the creation of limitless novel fantasy universes, might be where all sentient beings are headed. So maybe advanced civilizations just aren't interested in colonizing the galaxy, or communicating with it.

Your belief is wrong

[BigU 03C0mpin]

It is not technically difficult or expensive to send messages into space. We've been sending them since 1895, at the speed of light. We just don't consider them to be intentional messages since they're daily broadcasts to us. Granted the majority are too weak to be of any real use, but that's the whole point, they arrive at Proxima in 4.5 years instead of X0,000 years.

The aliens knowing that they've received a sentient-species-transmission, and then more importantly, deciphering and understanding it is another order higher in requirements for successful communication, but pales compared to the sheer vastness of space. Due to distance, interference, evolution and power requirements the odds are against:

• A. Them receiving a usable signal
• B. Them deciphering it without anything to compare it to other than the signals following it
• C. Them having the technical savvy to locate the source
• D. Them having the technical savvy to send us back a usable signal
• E. Us understanding that we're receiving a response
• F. Us deciphering the response
• G. Us comprehending what they send
  
  Consider we've been transmitting into space for 121 years so far, that encompasses (from what I can find on stars within 100 ly) something like 10,000 stars. A response at that point takes effectively two and a half centuries to return, so for all intents and purposes they should be considered extinct, while being a mathematical possibility. And that's at the speed of light, not at the speed of Voyager.

Efficient comm almost indistinguishable from noise

[Ungrounded Lightning]

Communication networks are likely via line-of-sight laser or some means we can't comprehend, so there's no transmissions for us to pick up.

Spectrum is a limited resource. The more efficiently it is used, the more the resulting signal looks like thermal noise.

Early modulation schemes (CW, AM) were simple, sending extremely redundant signals. These would survive substantial noise and be recognizable, even at interstellar distances.

Thanks to the enormously improved price-performance of modern electronics, a lot of computation can be thrown at constructing and decoding waveforms that can squeeze the most out of the spectrum - and we have enough information to send to make it worthwhile. So modern modulation schemes (ODFM, CDMA, and other spread-spectrum techniques) look almost like noise - with a tiny bit of redundancy to synchronize the decoders at the receiving end. If you don't know what you're looking for, or there's just a little to much noise (for instance, if you're just a little to far away from the transmitter to recover the pilot signals) the rest of the signal might as well be thermal gibberish.

Heck, some of them (like CDMA) work by convolving the information with a pseudo-random "spreading function" to make it look JUST like noise if you can't regenerate the same pseudo-random function. Then they share the spectrum by using different spreading functions, so on decoding their signal "piles up" into something intelligible that rises out of the "grass" while the competing signals just get mushed around, changing from one pile of random junk to another.

So my preferred solution to the Fermi Paradox is that, a very short time (like a century or so) after a new civilization becomes detectable by radio signals, it doesn't necessarily die out, but does becomes UNdetectable again, as its radio technology improves beyond recognition at a distance.

Thus there's no need to assume, as TFA apparently does, that (oh HORROR!) virtually every civilization that made it to an industrial revolution immediately made their planet uninhabitable by intelligent (or any) life and died off. (Or fell victim to anti-technological environmentalists and reverted to freezing in the dark and not having the energy to transmit detectable radio signals.)

Re:Efficient comm almost indistinguishable from no

[pepsikid]

"So my preferred solution to the Fermi Paradox is that, a very short time (like a century or so) after a new civilization becomes detectable by radio signals, it doesn't necessarily die out, but does becomes UNdetectable again, as its radio technology improves beyond recognition at a distance."

I agree, and this same argument was made a couple of decades ago as humans transitioned to cabled transmissions from transmission of tv and radio over the air. The overall level of radio energy broadcast into space was thought to be dropping. Wifi and cellular phones seem to have flipped that trend again, at least for now. However, the way we use radio now possibly makes our transmissions less detectable over great distances. They'd just be seen as peaks in several bandwidths. Alien skeptics can probably find plenty of reasons to explain these as natural phenomena, lol.

O wait ...

[yusing]

"I've been listening, but I can't hear anyone talking on the other side of the mountain."

"I know ... that's because there's nobody over there."

The more plausible explanation

[nehumanuscrede]

is they're doing everything they can to keep their crazy ass neighbors, ( that's us ) who kill each other out of boredom, from noticing them.

You probably have one on your street. The crazy family you do everything you can NOT to interact with ?

Not that I can blame them. A species that can't even get along with themselves have no place in the rest of the universe. Better to let us die off from our own stupidity.

If true, this would be really great news

[PJ6]

because it would show that the Great Filter (such as a planet-killing industrial accident) is not in front of us.

I Call Bullsh*t On This....

[mlauzon]

Because people take it as cannon whatever our scientists say as fact, just because we [Humans] haven't achieved something yet that aliens have done already or now saying they are 'extinct' because we haven't heard from them yet. But seeing all the UFO sightings, etc. say otherwise!

Simple explanation for no alien contact

[Spadista]

A favorite recording artist shared this explanation he got from an astrophysicist friend: It might be an oversimplification, but it works for me. https://youtu.be/sNGUkdovn_8

Trump!

[martinfb]

The aliens came down and ... saw Trump! Then said "Shhhhh! Be silent! This species is worth avoiding! They'll be extinct soon anyway."