We May Be All Alone In the Known Universe, a New Oxford Study Suggests (fortune.com)

A new study by Oxford University's Future of Humanity Institute determined that it's quite likely humans are alone in the observable universe. Fortune reports: The study looked at the Fermi paradox -- the apparent discrepancy between the seeming likelihood of alien life, given the billions of stars similar to our sun, and the scant evidence that such life actually exists. The paradox was named after physicist Enrico Fermi, who famously asked his colleagues at Los Alamos, N.M.. "Where Is Everyone?"

The study authors then examined various hypotheses and equations used to resolve the Fermi paradox. The results weren't pretty: "Our main result is to show that proper treatment of scientific uncertainties dissolves the Fermi paradox by showing that it is not at all unlikely ex ante for us to be alone in the Milky Way, or in the observable universe. Our second result is to show that, taking account of observational bounds on the prevalence of other civilizations, our updated probabilities suggest that there is a substantial probability that we are alone." SpaceX CEO Elon Musk cited the study's conclusions as an "added impetus" for humanity to become a spacefaring civilization capable of extending life beyond Earth. He tweeted: "This is why we must preserve the light of consciousness by becoming a spacefaring civilization & extending life to other planets..."

Comments

Better pray that there's intelligent life up above

[waynemcdougall]

https://www.youtube.com/watch?...

Fermi Paradox is useless

[locater16]

The Fermi Paradox is an utterly useless test. It takes variables you have no data on and then says to compute their probability.

Statistical probability, to be of any use in the real world at all, must by definition be based off already measurable data. That we have basically no measurement of any of this data means it is impossible to use the supposed equation of The Fermi Paradox to determine anything at all.

That this "equation" is mentioned with anything like passing respect should be considered a joke. That a paper from Oxford uses it is, one would hope, a joke from a couple drunk frat students hoping to get an easily published paper out to boos their careers.

Re:Fermi Paradox is useless

[Anonymous Coward]

you can use whatever you like. The reality is locater16 is correct. We have almost no data to build any sort of statistical model with. We can't even conclusively say their is no life in our solar system except on earth with any real certainty. At this point we only have a single data point.

Re:Fermi Paradox is useless

[WalksOnDirt]

Fermi's paradox is telling us something, just not a lot. There is probably no other expansive, technological civilization in the Local Group. That has always looked most likely and it probably always will.

Re:Fermi Paradox is useless

[smi.james.th]

I'm going to be pedantic here and point out that there's a difference between the Fermi paradox and the Drake equation, I think you're referring to the latter. Fermi simply asked the question - if the universe is so big and so old, where is everyone else? Frank Drake came up with the equation and the variables to which you're referring, and Carl Sagan popularised it by estimating these probabilities quite optimistically high.

Re:Fermi Paradox is useless

[religionofpeas]

Simple answer to the paradox is that space is just too big. Technology to visit other stars may not be possible, or be sufficiently rare that expansion can go undetected.

Re:Fermi Paradox is useless

[meglon]

Fermi's paradox is telling us something, just not a lot. There is probably no other expansive, technological civilization in the Local Group. That has always looked most likely and it probably always will.

No, it hasn't always looked most likely, and quite frankly it never will.... at least not in the next 1000 years or so. Our data points for life in the observable universe, the local group, or even our galaxy is so infinitesimally small that one would have to be a complete idiot to suggest it says anything other than "we don't have a fucking clue."

Re:Fermi Paradox is useless

[The Evil Atheist]

You should read the Three Body Problem and the rest of the series.

Re:Fermi Paradox is useless

[AmiMoJo]

The Drake equation isn't supposed to give us a single answer though, it's a tool for exploring the range of possibilities.

Given what little information we have to estimate some reasonable limits to the parameters of the equation we can then calculate the range of probabilities, and then see what sort of evidence we should be looking for to narrow things down or increase/decrease the probability that there are other civilizations out there.

Re:Fermi Paradox is useless

[mentil]

The universe is only 'old' from our point of view. A much colder planet where its life's metabolism and reproductive rates are low, might evolve much slower than life on Earth. Imagine microbes that reproduce once a millennium. From their point of view, they wouldn't have a Fermi paradox because either there'd be aliens zipping around everywhere already, or the universe is still 'only a few 10s of billions of years old'.

Re:Fermi Paradox is useless

[Applehu Akbar]

I wouldn't even start to consider applying the Fermi Paradox until we have thoroughly explored our own solar system.

Re:Fermi Paradox is useless

[someoneOtherThanMe]

So you're saying that all the Martians just went for a long holiday?

Re:Fermi Paradox is useless

[war4peace]

Not really, no. Chemical reactions at temperatures above zero degrees Celsius happen at certain speeds, and life depends on those chemical reactions.

Re:Fermi Paradox is useless

[ilguido]

The Fermi Paradox is an utterly useless test. It takes variables you have no data on and then says to compute their probability.

There are not variables in the Fermi Paradox, otherwise it would not be a paradox but an equation or a function. I do not know why you mentioned an equation, but probably it is because you do not know what we are talking about.

Note: I find it particularly annoying that random guys on the internet think they are masters of the known universe and _every time_ there is a discussion, you have to read caustic, trenchant comments using words like "utterly useless", "drunk frat students", "easily published paper out to boo[t] their careers". Discussions are rational processes, not political calls to arms, where you have to convey simple concepts to masses of mindless commoners.

Re:Fermi Paradox is useless

[Oswald McWeany]

Simple answer to the paradox is that space is just too big. Technology to visit other stars may not be possible, or be sufficiently rare that expansion can go undetected.

It could also be, that if you are travelling between stars or maintaining a high tech civilization you eventually realize, "Hey, Advertising our existence to the world may not be a good idea."

Even if you're not of the mindset to (wipe out your rivals before they wipe you out, just in case they're hostile) you will probably have the mindset: don't advertise your whereabouts just incase people who ARE of that mindset exist.

Re:Fermi Paradox is useless

[JoshuaZ]

The "space is just too big" argument doesn't work. First, there are no physics barriers to visiting other stars, purely engineering ones. Second, many stars are relatively close together. If you have a cluster of stars which are at most a light year away from each other and with many on the order of light months, the idea that one couldn't go from one to the other is the height of arrogant assumptions that technology isn't going to improve. Third, many of the signs of a lack of civilizations are far stronger than not just meeting them. We see no attempts by anyone to apparently communicate with other civilizations We also see no signs of any sort of megastructures like Ring Worlds and Dyson Spheres. See https://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm. But if spreading out isn't possible, then the incentive to make large systems in one's own star system to make efficient use of the resources there goes up massively.

Re:Fermi Paradox is useless

[swillden]

The Fermi Paradox is an utterly useless test. It takes variables you have no data on and then says to compute their probability.

You mean the Drake equation, not the Fermi Paradox, and you're wrong about its usefulness, as you'd know if you bothered to read the paper. The authors make a very convincing statistical argument that the Drake equation actually resolves the Fermi Paradox.

Statistical probability, to be of any use in the real world at all, must by definition be based off already measurable data.

True

That we have basically no measurement of any of this data

False. As the paper points out, we can estimate the distribution of many of the astrophysical numbers with relatively low uncertainty -- a few orders of magnitude. And while the others are much more difficult, when we don't know how to estimate a parameter, it is often feasible to bound the parameter and estimate the degree of uncertainty. In this case, the authors construct plausible estimates for the uncertainty of the really difficult parameters. The uncertainties are enormous precisely because we know so little. For example, they estimate that our best estimate of f_l ranges over 200 orders of magnitude. They note that this is a conservative estimate, that the actual uncertainty may be much larger, but that larger uncertainties merely strengthen their result.

The authors assume that the parameter values are uniformly distributed, calculate the resulting PDF of N and conclude that based on our best knowledge (which is very poor -- that's the whole point of the paper, to make sure the paucity of data is properly considered), there is a significant probability that we are alone in the galaxy, and in the observable universe. Their PDF also shows that there is a significant probability that we are not alone. In fact the probabilities of being alone and not being alone are close to equal.

Thus, the paper rigorously demonstrates that the Fermi Paradox is not paradoxical, precisely because we cannot estimate the parameters to Drake's equation. They show that because our knowledge is so poor, universes that are both empty and teeming with intelligent life fall well within the bounds of a careful, rational, and mathematical analysis based on our best knowledge.

In short, they rigorously demonstrated that your intuition about Drake's equation is correct, that our knowledge of the parameters is so weak that the resulting equation does not allow us to predict anything.

However, they also note that the amount of effort we've put into SETI provides us with actual data we can use to revise our estimates of the Drake Equation parameters, albeit only a little bit. They apply Bayes Theorem under a few different models to update their uncertainty estimates, and use the updated parameters to recalculate the probability that we're alone. This is a process that we can continue over time, updating the parameter PDFs based on observations (of various kind, not just SETI null results), gradually narrowing the uncertainty.

That a paper from Oxford uses it is, one would hope, a joke from a couple drunk frat students hoping to get an easily published paper out to boos their careers.

You should read the paper. It's actually quite carefully reasoned and interesting.

Re:Fermi Paradox is useless

[ToTheStars]

With current technology, it is estimated that we could send a mission to other stars in a matter of ~1,000's-10,000's of years (using something like "Project Orion" nuclear pulse propulsion: https://en.wikipedia.org/wiki/... ). That's a long time from a human perspective, but it's very short compared to the lifetime of the universe, and if we envision a "binary colonization" (we send two missions to nearby stars -- Alpha Centauri and Epsilon Eridani, for example -- and they each land and built two missions, each of which goes forth and builds two more, etc.) then the entire galaxy can be colonized in a few million years, which is still a small fraction of the galaxy's age.

It is possible that not enough intelligent life wants to do this to make it happen, but the distances between the stars themselves is not a great explanation for why it hasn't.

Re:Fermi Paradox is useless

[ath1901]

The Fermi Paradox is not the Drake Equation.

What I think the authors did is use a Drake equation, calculate the uncertainties, guess distributions for the uncertain parameters and calculate the chance of seeing no life in the visible/accessible universe. They solve Fermis Paradox by showing it is not unlikely at all that we are alone (thus no paradox).

I for one like this kind of research since it clears up some popular misconceptions about Fermis Paradox (like, that it is a paradox).

From the abstract (emphasis mine):

We examine these parameters, incorporating models of chemical and genetic transitions on paths to the origin of life, and show that
extant scientific knowledge corresponds to uncertainties that span multiple orders of magnitude. This makes a stark difference. When the model is recast to represent realistic distributions of uncertainty, we find a substantial ex ante probability of there being no other intelligent life in our observable universe

Re:Fermi Paradox is useless

[Bongo]

Quite. We started evolving to human, around 3 million years ago, and meanwhile, most of what we count as "technology" today only appeared in the last 12,000 (agriculture), to 300 (Western Enlightenment), to 115 (flight), to 70 (nuclear), years ago. We haven't begun to scratch the surface, and we don't even know where the surface is yet. Another 2000 years is nothing, yet unimaginable to us today.

My own simple explanation for the Fermi "paradox" is the Prime Directive.

Would you visit another world by zooming across the sky in your saucer yelling "WEEEEEE!!!!" and blasting fun targets with your ray gun, or would you simply transfer your consciousness into a humanoid body and walk around and talk to people?

Re:Fermi Paradox is useless

[war4peace]

Same if you're God, but then Occam's Razor comes along and makes you look like a fool.

Re:Fermi Paradox is useless

[Wycliffe]

The "space is just too big" argument doesn't work. First, there are no physics barriers to visiting other stars, purely engineering ones.

There are also social barriers. In order to reach our level of technology, a civilization likely needs to be hypersocial like us. Technology also brings with it a lot of security and comfort. A space faring species likely has reached the point of post scarcity. So in order to get on a generational ship you would have to give up all your friends, family, comfort, safety, etc.... I don't see most people being willing to do this. We are already as a society unwilling to take as many risks in the past and most people tend to stay close to home. Unless you are forced too like current refuges, most people are unwilling to do the whole "Oregon Trail" and risk dying on a journey for minimal gain.

Re:Fermi Paradox is useless

[Jason Levine]

Also, if your civilization has gotten to the point that you can travel between the stars, you might not be communicating in a way that Earthlings can pick up on. Imagine a group of people from the 21st century hiding in various locations and communicating using tools they have available (e.g. smartphones). Now have people from the 18th century try to detect said communications and see if these 21st century people are there and, if so, where they are. I doubt the 18th century people would have any luck detecting communications from the 21st century people.

Re: Fermi Paradox is useless

[Wycliffe]

Yet you're sitting here limiting your means of propulsion to ones we have thought of.

But you're assuming that there is something magical we haven't thought of. Maybe there isn't. Even if there is a magical new propulsion system, how do you create a ship that can travel at 1/10 the speed of light and doesn't get destroyed by the tiny debris it encounters along the way. It is relatively simple to calculate the impact energy of a golf ball or baseball size debris at 1/10 the speed of light and it would likely destroy anything we could create and you are likely going to come across stuff much larger than that and it would be impossible to navigate around this debris at that speed. How do you create a ship that can withstand debris hitting it at 1/10 the speed of light?

Re:Fermi Paradox is useless

[jbengt]

Imagine a group of people from the 21st century hiding in various locations and communicating using tools they have available (e.g. smartphones). Now have people from the 18th century try to detect said communications and see if these 21st century people are there and, if so, where they are. I doubt the 18th century people would have any luck detecting communications from the 21st century people.

You think that 18th century people wouldn't notice a cell tower?

Re:Fermi Paradox is useless

[drinkypoo]

The Drake equation isn't supposed to give us a single answer though, it's a tool for exploring the range of possibilities.

And someday when we have a meaningful amount of data, it may be that. But today, when we can't even tell if planets we've detected remotely support life, we lack it and so it isn't that. It's just a masturbatory device. bzzzzzzzzzzz

Re:Fermi Paradox is useless

[Junta]

Assuming there are no aliens seems a bit strong word, it'd be more along the lines of 'for all practical purposes, it doesn't matter if aliens exist at the moment so long as we don't know'.

You don't proclaim an 'unknown' in science as confidently one way or another.

Re:Fermi Paradox is useless

[Junta]

The general distances and scale do, however, explain why we would be hard pressed to observe them even if they *have* been moving from star to star. We keep assuming that because we haven't seen it, it isn't happening, but it's highly likely we wouldn't even be able to tell.

Space is big and we just can't observe it well enough to proclaim we know a bunch of stuff is missing yet.

Re:Fermi Paradox is useless

[Anonymous Coward]

You think that 18th century people wouldn't notice a cell tower?

It doesn't look like anything to me...

Re:Fermi Paradox is useless

[SuiteSisterMary]

You're confusing the Fermi Paradox with the Drake Equation.

The Drake Equation is a thought experiment, and is basically intended to demonstrate that so long as none of the values is 'absolutely zero,' life should be all over the damn place.

The Fermi Paradox is literally just a man in a village circa 10,000 BC saying 'well, I've never met somebody from somewhere else, so there mustn't be anybody else out there.'

Re:Fermi Paradox is useless

[blackomegax]

Genocide works, until you have a civilization that has evolved further than humanity in terms of ethics, and abandoned profit motive (or never got corrupt by money in the first place)

Re:Fermi Paradox is useless

[tinkerton]

That's what bothers me about Occam's razor: the idea that you somehow have to commit to the simplest conclusion when you have nothing else to go on, that idea is bogus.

When you can't draw conclusions, then don't draw conclusions, and simply move on. Of course moving on may resemble committing to the simplest conclusion, but in one case you commit to an idea, in the other case you don't.

Re:Fermi Paradox is useless

[religionofpeas]

It is possible that not enough intelligent life wants to do this to make it happen, but the distances between the stars themselves is not a great explanation for why it hasn't.

The distance plays a big role in not wanting this to happen. Personally, I'm not interested in funding a (very expensive) project that won't show any sign of result for thousands of years after I'm dead. Your "binary colonization" would fail to spread if success rate of landing, establishing a new civilization, and launching another round to a previously unexplored planet, was less than 50%.

Alpha Centauri and Epsilon Eridani, for example

Do these star systems have a suitable planet that we can travel to, land on, and then terraform to support human life, using only the stuff we brought on the ship ? If not, how far would we have to travel to find such planets ?

Re:Fermi Paradox is useless

[Waffle Iron]

If you have a cluster of stars which are at most a light year away from each other and with many on the order of light months, the idea that one couldn't go from one to the other is the height of arrogant assumptions that technology isn't going to improve.

In areas where stars are packed that close together and interacting gravitationally, planetary orbits may not be stable enough to allow advanced civilizations to evolve in the first place.

Re:Fermi Paradox is useless

[justthinkit]

Where is everyone else?

Moving away from us faster than we can travel. And for 80% or more of the Universe, moving at or near the speed of light...relative to us here on Earth. Good luck catching up with that.

Re:Fermi Paradox is useless

[Oswald McWeany]

If we had underground shelters in Madagascar, the heat might not be detectable above ground- our noise could be disguised, and even our waste products might not be recognizable as waste products to those in Madagascar if we're careful (incinerate it and pump it out into the ocean).

How advanced is Madagascar in this scenario- if they're not late 20th century, they probably wouldn't have sensitive listening devices or think there's anything strange in the chemical composition of the water.

Aliens could be living on Jupiter (I'm sure they're not- this is a hypothetical experiment), if we don't recognize their garbage, noise, and energy expenditures, even if we did see them we might think that they're natural by products of Jupiter and not the by-product of an alien species.

Re:Fermi Paradox is useless

[Green Mountain Bot]

And even if the planetary orbits are stable, the orbits of objects in those stars' equivalents of the Kuiper belt and Oort cloud would definitely not be, resulting in far more meteor activity on any potentially life supporting planets.

Re:Fermi Paradox is useless

[religionofpeas]

Genocide works, until you have a civilization that has evolved further than humanity in terms of ethics

Why would that happen ? If genocide works, then the genes that promote genocide will be more successful and they will multiply faster.

Re: Fermi Paradox is useless

[MikeDataLink]

>

Just a 1000 years ago we didn't know electricity, and magnetism. Today we know the other three fundamental forces. Granted all three are just theoretical at this point, but they were unknown till fairly recently.

And there may be many other forces we have yet to find. Imagine if our planet had no metals. Magnetism may have taken another 1000 years to properly discover and incredibly hard to experiment with. Our planet may lack the materials other planets have and vice-versa.

Aliens on other planets might have materials that made their discovery of new technology and forces much faster and easier.

Re: Fermi Paradox is useless

[religionofpeas]

Such a limiting mind.

If a limiting mind provides a good explanation for the Fermi paradox (and all other observations) then it suffices. There's no good reason to assume all kinds of magic that we don't need to explain what we see.

Re:Fermi Paradox is useless

[blackomegax]

You're assuming that genocide is a genetic trait, when it isn't. Ethics are taught.

Re:Fermi Paradox is useless

[WalksOnDirt]

No, wee think we know how to efficiently search for other technological life even if we technically can't do it yet. Someone else could do the same to find us. The fact that they apparently haven't suggests that they are not there to try.

This isn't certain, as there are other possibilities, but this is the most likely one.

Re:Fermi Paradox is useless

[lgw]

The underlying question of the Fermi Paradox is "why has no other species in our galaxy every created self-replicating machines to explore". The entire galaxy would be explored by that approach in 10s or 100s of millions of years, so we'd expect to see evidence of such in our own system.

The best answer is probably "we've only looked closely at a tiny percentage of our own system". If some random asteroid has been turned into a robotic manufacturing facility (and then shut down), it's pretty unlikely we've have discovered that yet.

There's no real reason to expect that we'd detect alien communication, or travel, or recognize advanced civilizations as something different from the natural working of the universe. What we can reasonably expect to find one day is any evidence that we were visited by self-replicating machines. We could also expect to find someone deliberately signalling us (or the galaxy as a whole), but it's hardly a paradox that we haven't seen that.

Re:Fermi Paradox is useless

[lgw]

There are megastructures that make a lot more sense than Ring Worlds and Dyson Spheres, that are stable, practical as an extension of known technology, and would serve the purpose of increased standard of living for a growing population. However, there are a lot of such approaches, and we only know how to look for a few of them, and we haven't looked very hard.

Re:Fermi Paradox is useless

[lgw]

That requires that aliens be easy to observe - we've barely looked, after all. That always seemed like a shaky assumption, and there's growing evidence that's it's false.

But on the other hand, 100% of planets in the habitable zone that we've closely observed have intelligent life. That's the data we have.

That's why it's a paradox: the evidence we have suggests alien life should be pretty common, but we don't see any, so what gives? The easy answer is "we haven't looked very hard".

Re:Fermi Paradox is useless

[lgw]

Occam's razor is "don't needlessly multiply entities", that is, prefer theories with the minimal assumed "things we've never seen". But that's a weaker statement than "never assume anything not in evidence".

Re:Fermi Paradox is useless

[lgw]

The question is: why don't we see them here, in our system. If any one species anywhere in the galaxy had a program of self-replicating exploration (robotic probes are much easier than expanding colonies), they'd have visited out system and left some evidence of such. So where are they?

The obvious answer is "we've barely looked", even in our own system.

Re:Fermi Paradox is useless

[jeff4747]

There is probably no other expansive, technological civilization in the Local Group.

No other detectable expansive, technological civilization in the Local Group.

One of the assumptions of Fermi's paradox is that an advanced civilization would be communicating by RF, and that their RF signals would be extremely powerful.

But we have little reason to think this is actually true. We have one example (us) and we are using weaker and weaker RF as our technology advances. Giant AM radio stations have been replaced with lower-power FM stations, and then even lower-power digital radio stations. Even RADAR stations are weaker than they used to be. Cell towers are ubiquitous, but way, way, way less power than radio stations.

Then there's also the fact that RF is an extremely poor way for an interstellar civilization to communicate simply due to the distances involved. For example, sending a message to Proxima Centarui and receiving a response would take more than 8 years. Communications that slow is going to result in widely divergent societies. Which means you don't have one interstellar civilization, you have many single-solar-system civilizations.

So if there actually is an interstellar civilization, it's not using the technology we are looking for. We'd have to find an incidental emission (say, explosions from a giant space battle). With the size of space, we can pretty much guarantee we will not be looking in the right direction at the right time to see that emission, and the incidental nature would make the signal so extremely weak that we'd probably miss it even if we were looking in the right direction.

Re:Fermi Paradox is useless

[Cajun Hell]

That we have basically no measurement of any of this data means..

..that here are a lot of terms that you might want to study in order to get a better understanding of .. everything.

It doesn't really take variables that you have no data on and say to compute something; it takes variables that you have no data on, and shoves them in your face, saying "you need to get more data, because imagine the things you could figure out if you had any fucking clue what these numbers might actually be."

If you're taking it too literally, then take a step back. Fermi and Drake aren't so much trying to really give you an answer as remind you how damn hard the problems really are.

Re:Fermi Paradox is useless

[iMadeGhostzilla]

It gives people a scientific-looking excuse to dream, that's all. As such, my view on that is let them. I don't see a harm in it, even though I think it's BS for exactly the reasons you mention.

Re:Fermi Paradox is useless

[jeff4747]

We see no attempts by anyone to apparently communicate with other civilizations

We've been looking for radio signals Why would they communicate via radio?

If you take us as a reasonable example of a normal location in the universe, communication via radio (or any light) with the nearest star would take more than 8 years (transmit + receive time). Which means if we did send people to Proxima Centarui, we wouldn't have one interstellar civilization. We'd have two single-solar-system civilizations. If communications takes that long, the two societies are going to diverge a lot.

On structures, we can barely resolve planets and do so via the transitory effects on their star. If there is a Dyson sphere, we won't see it because we won't see the star. If there's a ring world, we won't see it because the effects on the star are not transitory.

And that assumes Dyson spheres or ring worlds are practical enough and useful enough to be built. That's not actually clear - even with magical levels of technology, we couldn't build a Dyson sphere around Sol. There isn't enough stuff in the solar system.

Re:Fermi Paradox is useless

[Falconnan]

Yeah... No. Though I understand the direction you're heading in, commoner is a birth class, and we are not (in name at least) an aristocracy. Now if you're suggesting that the dispassionate wish to limit the excesses in public discourse, that's fine. Now that that's over...

Any variable value placed into the Drake Equation is at this point speculative. Of course we couldbe alone, but the odds are hard to predict. Further, there are variables that affect the ability of technology to get into space in the first place. These could include sufficiently massive planet preventing space travel, lack of sufficient materials to build space-worthy craft, lack of sufficient land mass to support a civilization with the necessary infrastructure, or maybe just a lack of desire. We can't know. And it's not like we could detect another civ like our own more than a dozen light-years out anyway.

Re:Fermi Paradox is useless

[jeff4747]

No, wee think we know how to efficiently search for other technological life even if we technically can't do it yet

No, we really don't. We used to think we'd find them via radio emissions. But the one example we have (us) is getting quieter as technology advances. We have cell towers everywhere but they are way, way, way less powerful than the giant AM radio stations we used to have.

Since radio falls off at 1/d^2, you'd have to be extremely close to the source in cosmological terms to detect even our old AM and TV signals. The roughly 70 light year bubble around us where you can detect our radio signals due to how long ago we started using high-power radio is pretty close to the maximum distance it is going to be due to the weaker signals we now use. Even a 100 light year bubble is a very, very, very small distance when you're talking about interstellar civilizations.

And it's quite silly to assume an interstellar civilization would use radio to communicate. It's too slow to hold a civilization together. 8.6 years to send a message to Proxima Centarui and receive a response, and that's the closest star to us. On that timescale, the two star systems would massively diverge in culture and would no longer consider themselves part of the same civilization relatively quickly.

Re:Fermi Paradox is useless

[jeff4747]

There's nothing special about zero degrees unless you want to assume "all life requires water in its liquid state"

Well, it does.

Water has unique properties that is utterly vital for life. For example, water freezes from the top-down because ice floats. That top layer of ice provides insulation that keeps the water underneath from freezing. If ice behaved like every other solid, water would freeze from the bottom up, killing everything in it before it had the chance to evolve a way to survive freezing.

And that doesn't get into the many other features of water that appear to be critical for life to exist at all.

There's some people postulating that ammonia could perform a similar role in colder planets. But this has it's own problems, such as ammonia being larger than water and not as polar. Something might have found a way to make ammonia work, but it seems unlikely.

there's also nothing special about chemical reactions, or even chemicals, if you're an intelligent magnetic eddy living on the surface of a neutron star.

There's nothing special about physical existence if you're a ghost either. That doesn't mean ghosts exist. Unless you can demonstrate a way that a magnetic eddy could become intelligent, you're just throwing out random bullshit. For example, how does it manage to maintain it's integrity, especially in the presence of the much stronger magnetic field around it? We know how things on Earth maintain their integrity when immersed in water, and it's simple, random chemistry that gives rise to it. What simple, random part of magnetism would result in a long-lasting self-organizing eddy?

Re:Fermi Paradox is useless

[arth1]

The "space is just too big" argument doesn't work. First, there are no physics barriers to visiting other stars, purely engineering ones.

That may be true for our local neighbourhood, at present.
But there are physics barriers to visiting far away stars. The expansion of the universe causes stars that we can now see to be outside our future light cone, and we can never ever reach them or even signal them.

Re:Fermi Paradox is useless

[SlideRuleGuy]

In fact the probabilities of being alone and not being alone are close to equal.

From the actual paper's Conclusion:

"...we find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe (53%–99.6% and 39%–85% respectively). ’Where are they?’ — probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable."

Re:Fermi Paradox is useless

[denzacar]

Nah, not really.

Liu Cixin is a poor writer with a limited imagination and knowledge regarding technology and ZERO understanding of even human psychology, let alone ability to imagine a properly alien one.
Also, when he DOES imagine something - he fails to connect the dots.

He imagines an alien race which can "unfold" a proton across 8 dimension, in order to create movable-at-speed-of-light proton-sized computer-robots which can block all particle research on Earth at will.
They can also create spaceships with which said race will invade Earth in 400 years.
Because their planet is doomed and they need breeding space.
Oh... and it's doomed because every random number of years the surface of their planet becomes unsustainable for life, so among other things, they've evolved the ability to hibernate for thousands of years.

So...
Not only is it a race with applied string-theory tech (basically magic), quantum-entanglement interstellar communication, spaceships which can reach another star in a reasonable time (and other even faster spaceships) AND biological hibernation... basically ideal explorer-colonist race... with magic tech...
But they can't dig holes. Or build orbital space stations.
Not even after seeing humans doing EXACTLY that.

On top of that... his outlook of life and geopolitics peaked at "doom and gloom world" and "mutually assured destruction".
And less is said about his "my perfect waifu database" ideas the better.

But he does have a lot of PR pushing him as the next Asimov or Clarke, which he is not in any shape or form.
It's almost as if there's something connecting his writing with aggressive marketing or a Chinese government program to promote science fiction.

Re:Fermi Paradox is useless

[arth1]

If considering timelines, keep in mind that:

1. Our sun is not a first generation star (or else we would not have metals)
2. Life took most of the Sun's life to evolve (and is now well past its halfway lifespan)
3. Travelling or signalling across vast distances takes a long time

There might not have been time enough for advanced life to have evolved close enough to us to notice.

Re:Fermi Paradox is useless

[djinn6]

We're not going to have the data until we actually discover alien life, at which point the equation is moot. For example, how would you know "the fraction of habitable planets that develops life" if you only have one example of a habitable planet with life on it?

Re:Fermi Paradox is useless

[HiThere]

You are wrongly complaining about the Fermi Paradox when what you should properly be complaining about is the Drake Equation. They aren't the same thing at all.

It's true that the Drake Equation is frequently used to answer the Fermi Paradox, but this doesn't mean that all answers to one apply to the other.

E.g., one possible answer to the Fermi Paradox is that advanced technological civilizations inevitably develop addictive computer games and become so introverted that they lose all outside interest. If this happens to be true the results of the Drake equation would have absolutely no relevance to the Fermi Paradox.

Re:Fermi Paradox is useless

[shadowrat]

we do try to make them look like trees.

Re:Fermi Paradox is useless

[datavirtue]

Agreed. This is garbage.

"and the scant evidence that such life actually exists"

False. I exist. We have tons of fucking evidence!! How dumb can you be?

Re:Fermi Paradox is useless

[datavirtue]

Technological civilization? Do spear chuckers qualify?

Re:Fermi Paradox is useless

[thecatt]

If that is true, who taught them to humans?

Re:Fermi Paradox is useless

[datavirtue]

Well you have reject nerds like Musk who can't think of anything but Space Trek as our ultimate evolution. It just hit me...these tech billionaires are going to kill us all. The road to hell is paved with great intentions. Dorks.

Re:Fermi Paradox is useless

[datavirtue]

Couldn't we harvest the grease and make it into Dyson plastic? What the hell do vacuum cleaners have to do with this anyway?

Re:Fermi Paradox is useless

[swillden]

In fact the probabilities of being alone and not being alone are close to equal.

From the actual paper's Conclusion:

"...we find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe (53%–99.6% and 39%–85% respectively). ’Where are they?’ — probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable."

Yep. Within the orders of magnitude we're talking about, that's "close to equal".

Re:Fermi Paradox is useless

[Areyoukiddingme]

’Where are they?’ — probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable."

That forever unreachable poetic nonsense always bothers me. Given even an optimistic lifespan for our species, there are trillions and trillions of stars we can actually see that are forever unreachable. A good many of them aren't actually there anymore. Even stars have finite lifespans. A billion novas have already happened that we haven't even seen yet. It doesn't require any cosmological horizon for most of the universe to be forever inaccessible to humans.

Re:Fermi Paradox is useless

[blackomegax]

We call those "animals", behaving animalistically. Humans, at least the ones with humanity, are evolved beyond animal impulse, and any space faring species would have to follow this same evolution of ethics, else they destroy themselves.

Re:Fermi Paradox is useless

[hey!]

You're attacking a kind of straw version of the Fermi Paradox.

People get hung up on the name "paradox", but that name tells you right off the bat that the Fermi Paradox is not meant to be approached as a theory or hypothesis, which by definition cannot be paradoxical. The Fermi Paradox doesn't organize what we know, it organizes what we don't know, which at this stage is more useful.

If you line up what little we do know and put it together with some reasonable extrapolations, the result isn't what you expect. It's not useful in the way a theory would be (e.g. in generating experimental null hypotheses), but it's useful at a much more preliminary stage of the scientific process -- selecting issues to investigate. Either (a) what we think we know is false or (b) what seems reasonable to us is false. These are both kinds of things worth looking into.

Re:Fermi Paradox is useless

[farble1670]

You're assuming that genocide is a genetic trait, when it isn't. Ethics are taught.

Genocide is a word with moral implications. You should ask if the drive to advance your own species / family line over others is a genetic trait. Which it will be, because any species / family with this mentality is going to wipe the floor with one that doesn't.

If we met an advanced space-faring species, what would be their advantage in treating us with respect? Anything they want to know about us they could learn through subjugation. Leaving us to our own devices leaves open the chance that in another 10,000 years we'd be competing with them.

Ethics are taught.

Humans have been warring since they figured out that banding together offered a survival advantage. There were no "ethics", just the drive to survive and propagate.

Who taught our closest relatives, the Chimps, their ethics?
https://www.usatoday.com/story...: https://www.usatoday.com/story...
Murder 'comes naturally' to chimpanzees: https://www.bbc.com/news/scien...
Monkey see, monkey kill: The evolutionary roots of lethal combat: http://www.latimes.com/science...

Re:Fermi Paradox is useless

[superdave80]

If you have a cluster of stars which are at most a light year away from each other and with many on the order of light months

Our NEAREST star is over four light years away.

Re:Fermi Paradox is useless

[JoshuaZ]

Really ? Let's see your math. Assuming we'd like to land a 10 ton craft on an Earth like planet 4.5 light years away in a reasonable timeframe (say 25 years Earth time). How much fuel, and what kind of propulsion (in terms of mass-energy conversion efficiency) would we need ?

People have made those calculations with Orion type craft. See https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)#Theoretical_applications. What you label as a "reasonable time frame" isn't doable, but journeys between star systems on the order of hundreds of years are completely consistent.

Assuming magical technology is even more arrogant than a reasonable extrapolation of current progress.

There isn't anything magical about nuclear propulsion

These structures are made from unobtainium and aren't passively stable. I wouldn't count on many civilizations being able and willing to build one. If you run out of room, genocide is a tried and proven solution, and much cheaper than building a Ring World. Also, most stars are too far away to see structures like that. Actually, most stars are too far away to see the star itself.

Solid ring-worlds and solid Dyson spheres cannot be made with known materials. The swarm versions lack those problems, and stability is a small issue for the swarm versions. And yes, most stars are too far away, but many are not. Please read the link I gave above- we've done systematic searches for all sorts of megastructures and found none. Also the fact that many stars are far away doesn't enter into it: if the nearby stars are a close to representative sample that shouldn't matter.

Re:Fermi Paradox is useless

[ememisya]

To their credit, the paper does state an ex ante probability of there not being any life beyond our own, within a certain percentage range. So they are certain that they can probably say that there isn't any life in the Universe beyond our own. Definitely maybe a useful thing. Certainly does not factor potential for human technological achievements. What if we can bend the Universe in the future to bring some of those impossible distances to the realm of possibility? I am certain I can say that's likely to be a thing. Anywhere between 1% to 99% by my own calculations.

Re:Fermi Paradox is useless

[The Evil Atheist]

Nice opinion.

Re:Fermi Paradox is useless

[Nethead]

Where's my up-mod points when something really good comes along.

Re:Fermi Paradox is useless

[mcswell]

Yeap, those of you who "think [you] are masters of the known universe" really annoy those of us who are.

Of course, my universe is pretty small, well under an acre...

Re: Fermi Paradox is useless

[ChrisMaple]

The periodic table pretty much names all the available materials anywhere, once you allow for isotopes. Your "lack of materials" conjecture is silly.

Re:Fermi Paradox is useless

[meglon]

I'm going to suggest that the "most likely" reason is something we haven't even thought of yet.

Your giving us far too much credit. We don't know how to search for technological life, the ideas for that are in the nascent stages at the moment; and the idea we can't "technically" do it yet is a massive understatement.... we've barely considered how to be able to do the easiest few ways we've thought about.

Re:Fermi Paradox is useless

[RespekMyAthorati]

in order to get on a generational ship you would have to give up all your friends, family, comfort, safety, etc.... I don't see most people being willing to do this

Explorers have always been willing to drop everything to find something new.
Or better, travel in some sort of hibernation so the transit time is imperceptible.

Re:Fermi Paradox is useless

[RespekMyAthorati]

But there are physics barriers to visiting far away stars.

Only if by "far away" you mean "in a galaxy far far away".

Re:Fermi Paradox is useless

[RespekMyAthorati]

Our NEAREST star is over four light years away.

No, our nearest star is 150 million kilometers, or 10e-5 light years away.

Re:Fermi Paradox is useless

[superdave80]

Damnit...

Re:Fermi Paradox is useless

[meglon]

Well he is an Oxford professor.

That actually got me thinking...

https://www.fhi.ox.ac.uk/

Academics at FHI bring the tools of mathematics, philosophy and social sciences to bear on big-picture questions about humanity and its prospects.

So... not actual scientists... even the mathematicians are most likely probability and statistic guru's, which means again, not scientists.

Re:Fermi Paradox is useless

[darth.hunterix]

Nah, every once in a while I hear that "Vatican already has strategy in case aliens contact us". Hell, they allegedly even have passages from Bible that can be interpreted as proof that on only aliens exist, but after his crucifixion Jesus went to other planets to die for THEIR sins. You so much underestimate adaptability of religious people.

Re:Fermi Paradox is useless

[darth.hunterix]

You assume that 40 years is a long time. Now, it is for a human, but we have here on Earth organisms that routinely reach 1000 years. Now, they may not be the sharpest tools in the drawer and I don't expect them to come up with space travel any time soon, but it suggests, that we should not apply our own limitations to others. For aliens 40 years may be like a day to us.

Re:Fermi Paradox is useless

[WalksOnDirt]

You should be able to tell that Earth is life-bearing from far off. Why didn't they come, or send robots, and check us out?

Re:Fermi Paradox is useless

[Godwin O'Hitler]

Indeed. The only reliable data we have is that the probability of intelligent life in the Universe is exactly 1.
Now compare that with "the probability of intelligent life in the Universe is zero (uh ... except for ... y'know)."
I know Occam's razor is only a rule of thumb, but I have far more confidence in it than in Fermi's paradox.

Re:Fermi Paradox is useless

[Wycliffe]

Well you have reject nerds like Musk who can't think of anything but Space Trek as our ultimate evolution. It just hit me...these tech billionaires are going to kill us all. The road to hell is paved with great intentions. Dorks.

Non of these tech billionaires are jumping on the rockets and I doubt any of them will be in the early waves. They will send plenty of guinea pigs to pave the way before they ever dream of actually getting on a rocket themself. If you are talking about generational ships, probably the only thing that would get a billionaire on one would be the right to be king and even then it would be doubtful.

Re:Fermi Paradox is useless

[bingoUV]

Unless you can demonstrate a way that

No, we are talking about life that we don't know about. You have to demonstrate a way that no "life" is possible without water - including life that we don't know about.

Re:Fermi Paradox is useless

[sarren1901]

We haven't really become a space faring species just yet and there is still plenty of time for the world to go nuclear. The more our technology advances, the fewer people required to destroy the place.

While there is almost certainly intelligent life in the universe, we very well may never find it given how large even the observable universe, let alone the rest of it we can't see.

Maybe when we develop better telescopes we'll be able to see something we can't see today.

Or it could be that most advanced civilizations blow themselves up before truly becoming space faring.

Re:Fermi Paradox is useless

[jeff4747]

You not understanding the chemistry doesn't mean I did not do so.

Re:Fermi Paradox is useless

[jeff4747]

We have a very closed ecosystem called earth so we have absolutely no idea what other forms of life could evolve in vastly different environments.

The laws of physics apply in those other environments too. And those laws create certain effects in chemistry. Those effects are required for life to appear, because you need something not-alive that can still organize somewhat before something alive can form.

So yes, we can say that liquid water (or maaaaybe liquid ammonia) are required for life, because those are the chemicals required to create the environment where life can form.

Re:Fermi Paradox is useless

[jeff4747]

1) Why would they? You can't assume they'd care enough about us to do so.

2) If they did care enough, how do we know they didn't check us out?

Re: Fermi Paradox is useless

[bingoUV]

How does that cover "life" that we don't know about ? In your "chemistry" , you have made a lot of assumptions about the "life" : none of which are justified for an unknown kind of "life" .

Re:Fermi Paradox is useless

[KingBenny]

sounds about right ... i was gonna say "and there might or might not be an actual flying spaghetti monster hiding behind the gas mines of UR anus" but until we open the box we'll never know so thats a long way for musk to go but what said sounds better lol do these people get paid for that ? like politicians voting on wether you can take an mp3 on an airplane if you bought it in france and you're flying to london , cos they DO get paid for that

Re:Fermi Paradox is useless

[JakeBurn]

"Leaving us to our own devices leaves open the chance that in another 10,000 years we'd be competing with them."
I don't buy this logic. If, in 10,000 years, homo sapiens are flying through space at .9 the speed of light, would they even care that chimpanzees had started making and using fire for food preparation? Your assumption is that one of these groups will stop advancing while the other catches up and that doesn't make sense unless some catastrophe occurs.

Re:Fermi Paradox is useless

[farble1670]

Your assumption is that one of these groups will stop advancing while the other catches up and that doesn't make sense unless some catastrophe occurs.

No, I assume that the chance that two races will not advance at exactly the same rate over 10k, 100k, or millions of years.

If, in 10,000 years, homo sapiens are flying through space at .9 the speed of light, would they even care that chimpanzees had started making and using fire for food preparation?

No, but in 1 million years they'd care if chimps were competing with them for the same limited set of habitable planets.

Re:Fermi Paradox is useless

[kuhnto]

Great point! Just to add, Think about how our communications technology started... More power to reach farther. Not look at how technology has morphed through time to provide a more portable medium. Because of this, portable power now becomes a much more important commodity and communication EFFICIENCY becomes the primary driver of RF technology. as a result the Earth was noisy for a bit before becoming more and more quiet.

Re:Fermi Paradox is useless

[Wycliffe]

Explorers have always been willing to drop everything to find something new.
Or better, travel in some sort of hibernation so the transit time is imperceptible.

There is a huge difference between exploring a new corner of earth with a stable ecosystem similar to your own and exploring the wasteland that is space. The Sahara and Antarctica are both orders of magnitude more hospitable than space and you don't see people lining up to live in the middle of the Sahara. Unless we either find another hospitable planet or learn to terraform planets, you aren't going to have people lining up to explore space. The costs and distances are another huge factor. You can't compare something like the Oregon Trail with its 4-6 month travel time and breathable air and relatively cheap equipment with interstellar travel with multiyear travel, extremely cramped quarters, and huge costs/risks. And if we could build a comfortable generational ship, why not just live on it permanently. Park it in Antarctica, the Sahara, the bottom of the ocean, or the moon.

Re:Fermi Paradox is useless

[q4Fry]

I imagine 18th century people are much better at identifying trees and tree abnormalities than I ever was or will be.

Re:Fermi Paradox is useless

[q4Fry]

Our NEAREST star is over four light years away.

No, our nearest star is 150 million kilometers, or 10e-5 light years away.

With respect to your somewhat amusing pedantry, it is entirely reasonable to read GP's comment as including Sol in "Our."

Re:Fermi Paradox is useless

[denzacar]

Feel free to read the books.

All I mentioned above is what he wrote. AND MORE...
Like how the motivation for human traitors who contact the aliens to come and exterminate the humanity is that they are extreme treehuggers, trying to practice inter-species communism.
Or how "our heroes" surprise-kill everyone on a ship (boat, not star-) by stringing up nanowires in ship's path, which then silently slice everyone on the ship in two, before anyone has a chance to destroy any data.
Which works because apparently ships move through the Panama canal faster then one can see and react to people in front of them being sliced in half.

Also, feel free to read the articles I linked above.
"Ken Liu, a Hugo Award-winning author and the translator of the popular Chinese science-fiction novel 'The Three-Body Problem'" works for a SciFi shop which produces "corporate visioning" - "customized stories for the likes of Visa, Ford, Pepsi, Samsung, and NATO."
And Chinese ARE actively pushing for more Chinese SciFi. Have been for a while now.
At least since the tenth 5-year plan (2001-2005).

http://www.gov.cn/english/offi...

We need to disseminate scientific knowledge, combat ignorance and superstition, and encourage healthy lifestyles. We need to further develop various cultural undertakings, such as literature and art, journalism and publishing, and radio, film and television. We should adhere to the principles of serving the people and socialism and of "letting a hundred flowers blossom and a hundred schools of thought contend." We need to produce more and better cultural and intellectual works. We need to maintain the correct orientation of public opinion, and place strong emphasis on the establishment and management of new information media. We need to build more libraries, cultural centers, science and technology centers, museums, archives, and recreation centers for juveniles and senior citizens. Mass participation activities should be continued to promote cultural and ethical progress. We need to deepen reform of the system for managing cultural undertakings, improve the economic policies concerning cultural undertakings, and promote the development of industries related to culture.

Also... this part...

We must use legal means to combat ethnic separatist activities, religious extremist forces, violent and terrorist activities, cults, and illegal activities carried out under the guise of religion. We need to continue our campaign against the Falungong cult, and further expose and condemn the anti-human, anti-social and anti-science nature of the cult, which has become a tool for domestic and overseas forces hostile to our socialist government. We need to mete out severe punishment to the small number of criminals while making unremitting efforts to unite, educate and rescue the vast majority of people who have been taken in.

Is it surprising, after reading all that about cults, that those traitors of the human race in the books act very much like a cult?

Let's ask the oracle!

[SciCom Luke]

"Are we alone in the universe?" she asked.
"Yes," said the Oracle.
"So there's no other life out there?"
"There is. They're alone too."

Re:Let's ask the oracle!

[Zontar The Mindless]

SciCom Luke wins the thread. I think we're done here, folks.

Re:Let's ask the oracle!

[SciCom Luke]

In all fairness, I shamelessly stole it from James Miller: https://pics.me.me/yes-oracle-...

Re:Let's ask the oracle!

[Bongo]

That reminds me that there's the notion that,

reality REPEATS itself. [1]

When something appears, it kinda appears everywhere. So it would be surprising if there were not a lot of other "M-class" planets out there.

Besides, the belief that we are alone, has a weird "we are special God-created creatures" stink about it.

As an atheist, I would assume life is everywhere, as there is nothing special about us. The only question is, how far away are they?

[1] reality, Nature, the universe, fundamental laws, etc.

Re: Let's ask the oracle!

[phantomfive]

Your first three paragraphs are great, but the next two are pure bias. I agree with your conlusions, but if you're open minded you need to be open to things that annoy you. "We are alone" in no way implies there is a god. That's a weird bias you picked up.

Re:Let's ask the oracle!

[Anonymous Coward]

'tis rude not to link to the original source:
http://theoatmeal.com/comics/o...

Re: Let's ask the oracle!

[Bongo]

I agree with your conlusions, but if you're open minded you need to be open to things that annoy you. "We are alone" in no way implies there is a god. That's a weird bias you picked up.

Fair point about being open to ideas I don't like. I agree.

The implication comes from, why would this one planet be so different to the, something like, ten raised to the twenty-four planets, in the universe? Even if we are one in a trillion... there's plenty of life out there. The universe seems to have had no trouble manufacturing a wide variety of stars and planets all over the place, everywhere. Why does it suddenly struggle to manufacture life, and so does it only a single time?

Once it got going here, it all happened very quickly. Why, elsewhere, would it stop just short, everywhere else, of an animal with capacity for abstract thought? Why would we be so "special"?

Either we are a natural part of the patterns of the universe and natural laws, or some weird magical power put us here. I don't think this is bias, I think it is a natural conclusion. So yeah, if we are special, then it implies gods and stuff (and they in no way would have to resemble any man-made idea about god, just that it is some otherworldly creative something).

Much easier to assume life is normal and repeatable.

I'd buy that intelligent life appears only a few times in a galaxy. But once in a universe? Nah.

Re: Let's ask the oracle!

[Bing Tsher E]

With lots of money you can buy almost anything, except wisdom. Ask Larry's buddy Steve J. about that...

Re: Let's ask the oracle!

[mark-t]

Assuming that we are alone, the reason for it would likely simply be because complex life is so astoundingly improbable, and that we just plain got very lucky.

Of course, it's difficult to imagine such a vanishingly small probability that it would not be likely to recur somewhere in the vastness of the universe... but that doesn't mean it isn't possible.

And I don't mean to suggest that we necessarily are alone or make any statement about the likelihood of complex life.... I just mean that if we are alone, it would imply only that we were simply incredibly lucky to be here at all.

But don't worry about it, because if we are alone, we'll never know it.... we can keep on assuming that life exists out there, somewhere, simply beyond our current technological capacity to observe it, and never actually be shown to be wrong.

Re:Let's ask the oracle!

[Zontar The Mindless]

Well, it was certainly on-target, and I would have given you a +1, Insightful if I'd had any mod points today.

Thanks for sharing the source!

Re:Let's ask the oracle!

[GameboyRMH]

Indeed it would be shocking if there aren't other "M-class" planets out there, and there's almost certainly other life in the universe or likely even our solar system. But quite possibly no other intelligent life.

Intelligent life is a rare fluke of nature, on Earth we have only a few that can build tools at all, and only one that can build complex tools, harness fire, and clearly has language capabilities. It's not normal for a species to evolve a stupidly enormous energy-guzzling brain.

Re: Let's ask the oracle!

[Freischutz]

With lots of money you can buy almost anything, except wisdom. Ask Larry's buddy Steve J. about that...

Why go and ask him? All I have to do is watch Donald Trump talk.

Re:Let's ask the oracle!

[cascadingstylesheet]

"Are we alone in the universe?" she asked. "Yes," said the Oracle. "So there's no other life out there?" "There is. They're alone too."

Elf (in Rudolph): "Let's be independent ... together!"

Re: Let's ask the oracle!

[phantomfive]

Either we are a natural part of the patterns of the universe and natural laws, or some weird magical power put us here.

This is a false dichotomy, someone gave you some bad logic. There are a lot of other possibilities, here is one:

Basically, of everyone in the universe, someone has to be first. Maybe we won the lottery. Sometimes that happens. It seems improbable, but by the anthropic principle, if we're here to observe it, then it happened to us.

Re: Let's ask the oracle!

[tbird20d]

One reason I have heard that the Earth might be rare as a cradle of life is due to the Moon. The Earth-Moon system looks to be fairly rare. Our Moon is quite large compared to the Earth. The tides, along with Earth being in the "goldilocks" zone for liquid water, may have played a critical role in the development of life. So it's possible that a combination of factors may actually contribute to Earth being a very rare environment. The rarity only has to be one in a trillion, trillion, for there to be little chance of life detectable elsewhere with current technology.

Re:Let's ask the oracle!

[Impy the Impiuos Imp]

So if the paradox holds, we are alone because even using clumsy slow ships, life should have clogged not just the galaxy but the universe by now.

Ergo we are the first, or close to it in a coincidence.

But...maybe it happened and we are in a simulation. An ethically questionable one to be sure, but maybe a simulation. In which case we would additionally have no reason to think our physics in any way resembles "the real world".

So...either there is no life out there, or there is, but "out there" is outside this simulation.

In neither case is there intelligent life out in (what appears to be) the cosmos.

Re: Let's ask the oracle!

[ChrisMaple]

You can buy the results of wisdom, i.e. wise statements. But without wisdom, you can't recognize them as being wise.

Re:Let's ask the oracle!

[thegreatbob]

Don't forget the Matthew Inman (theoatmeal.com) drawing that makes it what it is :)

Re:Let's ask the oracle!

[SciCom Luke]

Thanks for opening the door to the classic:

"We are all individuals!"
"No, I'm not!"

Re:Let's ask the oracle!

[SciCom Luke]

And Tim Berners-Lee, for inventing the internet, to get this picture to everyone, and the Joint Photographic Experts Group for the jpeg format. The list goes on and on. :-)

Re: Let's ask the oracle!

[Bongo]

Assuming that we are alone, the reason for it would likely simply be because complex life is so astoundingly improbable, and that we just plain got very lucky.

It is a nice combination of begging the question and invoking infinity. We are alone because life is virtually impossible; we alone defeated the impossible odds; how do we know impossible odds can be defeated? because we are here to see it. Hence, impossible odds can be defeated, but only once, by us.

God works in mysterious ways. How do we know? Because we can never see how the ways work, as they are so mysterious.

There's no God. We are not alone.

Re: Let's ask the oracle!

[Bongo]

I still think that is begging the question and invoking infinity. How do we know impossible odds can be defeated? Because we are here to see it! But only us, only once.

I don't see how people can honestly talk about defeating near impossible odds, whilst in all other areas of life, it would be a silly thing to do.

If a zebra suddenly appeared in my office, I would not say that quantum physics allows for a zebra to suddenly tunnel from Kenya to my office, even though the probabilities are virtually impossible, but the fact that I see it, proves it can happen, sometimes to someone. That's basically what the "we are alone" scenario claims.

Rather, I would look for a more LIKELY explanation, namely that somebody put a fucking zebra in my office and I would start looking for the rich joker who could manage that, probably a TV production company for some candid camera thing.

Re: Let's ask the oracle!

[phantomfive]

Think of it like this: someone wins the lottery. It's irrational, and that individual person shouldn't have bought a lottery ticket, but they did, and it turned out to be the most lucrative decision of their entire life. If we are alone in the universe, then we are like that lottery winner.

Rather, I would look for a more LIKELY explanation, namely that somebody put a fucking zebra in my office and I would start looking for the rich joker who could manage that, probably a TV production company for some candid camera thing.

That's a rational approach.

Re: Let's ask the oracle!

[mark-t]

It is a nice combination of begging the question and invoking infinity. We are alone because life is virtually impossible; we alone defeated the impossible odds; how do we know impossible odds can be defeated? because we are here to see it. Hence, impossible odds can be defeated, but only once, by us.

Not impossible... and not necessarily only once, but also not necessarily at all in the first place. It happened once..,. but saying that it happened once should imply it will or even is likely to happen again is like saying that because you win a lottery the very first time that you play, then you should expect that at least some of your friends ought to win the lottery the first time they play as well. Sure, it might happen... but the odds are sufficiently against it that it that it probably won't.... the odds were against you winning the lottery the first time you played as well anyways, so while that's proof that overwhelming odds won't actually prevent something from occurring, it's still not proof to expect something you can reasonably say is unlikely.

But for what it's worth, we don't actually know just how unlikely complex life is in the universe.... and if we never discover any other life, we will never actually know, regardless if we are completely alone or not.

But given that it's at least a falsifiable proposition that we are alone in the universe (since a single counterexample of complex life elsewhere will disprove it), it seems like the more sensible position to presume from a rational perspective to be the more likely scenario, and *IF* that is the case, then it follows that the reason for it would simply be that the odds of it must have been so astoundingly rare that we are simply just lucky to be here at all.

Of course, if we aren't alone, then it's all entirely moot... but as I said, as a falsifiable premise, it is arguably the more rational assumption to make in absence of any specific data to suggest that it might be in error, just as it is more rational to assume that there are no invisible flying elephants in my refrigerator than to offer any credibility to the notion that there might be.

I disagree

[Anonymous Coward]

I think the galaxy is a life distributing system.

Re:I disagree

[BlueStrat]

[I disagree ] I think the galaxy is a life distributing system.

More than that. I believe there's a good possibility that a "universe" (there may be more than one, ours) exists for the sole purpose of creating intelligent life that matures and advances to the point they have the ability to move outside that universe and exist there. They then create another universe and the cycle repeats. It's how extra-dimensional beings/species/civilizations "reproduce", if you will. I mean, what else do you do when you're effectively a God or Gods able to create a freaking *universe* FFS? Play Euchre?

There may already have been intelligent species that achieved "Ascendancy" long ago and are no longer here for us to easily find through signs of activity. We may be the first or the last in a long line of intelligent species or just one of many in the middle of that series of intelligent species. We just haven't "grown up" sufficiently to learn "the facts of "Life" yet.

Whether or not we survive long enough as a species to find out...?

Strat

Re:I disagree

[gtall]

Yes, and somewhere there are pink unicorns frolicking in the meadow. The Universe is big enough to generate just about anything, right?

Re:I disagree

[Insanity Defense]

while the development line that lead to our species is only about 7 million years old.

No. The development line is from the first life which is nearly as old as the planet. 90% of the time life was on this planet it was either single celled or simple multi cellular life.

Re:I disagree

[Freischutz]

Yes, and somewhere there are pink unicorns frolicking in the meadow. The Universe is big enough to generate just about anything, right?

Depends on who you ask.

Re:I disagree

[djinn6]

Some say the universe is infinite. If so, then pink unicorns are somewhere out there, maybe even invisible ones.

It's a Calculation problem

[hcs_$reboot]

As long as we don't have the right estimation of the probability that life exists on a planet, we cannot really assess if life exists or no. Now given the gigantic (known) number of galaxies containing a gigantic number of stars, even if that life probability is low, that would be quite a stretch to conclude life exists only on Earth.

Re:It's a Calculation problem

[Anonymous Coward]

We know Jesus lives in Heaven and Superman (used to) live on Krypton. So that's 3 planets already in the numerator. But don't try and bullshit me about global warming. NASA needs to cut that shit out.

Re:It's a Calculation problem

[m.alessandrini]

I don't know, it's true that there are billions of billions of stars and planets, but thinking of the billions of billions ways how random atoms and molecules can combine, to obtain something that vaguely resembles life, i.e. starting replicating and self-organizing and all the rest, I think it's not so absurd to think that it could have happened only a very few times in all the universe.

Re:It's a Calculation problem

[Anonymous Coward]

I prefer the Copernican (Mediocrity) principle regarding life in the universe. Its simply too vast for us to be special. If we cannot discover life like ourselves, then we should probably try to discover life unlike ourselves.

Re:It's a Calculation problem

[AHuxley]

Kolob https://en.wikipedia.org/wiki/... too AC?

Re:It's a Calculation problem

[m.alessandrini]

Well, evolution doesn't work by blind chance of course, that being the wrong assumption most religious people throw at evolutionists, but don't you think that at the very beginning the first self-replicating molecules or proto-cells must have originated randomly? Because otherwise your definition of "religious" is reversed with respect to mine.

Re:It's a Calculation problem

[mentil]

random atoms bumping together made life

It's not atoms bumping together. But when two amino acids love each other VERY much...

Re:It's a Calculation problem

[mark-t]

Now given the gigantic (known) number of galaxies containing a gigantic number of stars, even if that life probability is low, that would be quite a stretch to conclude life exists only on Earth.

Doesn't that depend on just how low that probability actually is? As vast as the observable universe is, it is still of finite size and age, and will eventually end at some finite point in the (extremely) distant future, and it is quite far from inconceivable that we are simply just lucky to be here.... at all. For example, what if the chances of life were one in some vastly huge number that is no more comprehensible than the vastness of the universe itself, like say graham's number (not that I am suggesting that the odds are that, specifically, I am simply using it as an example)... if the odds of complex life forming were ever that low then in fact it would probably be assumed that complex life would probably not form at all. We may be erroneously assuming that because we exist, that this implies that the probability of our existence was ever something that even began to approach likelihood or normalcy in the first place, but this isn't necessarily the case.

Re:It's a Calculation problem

[cascadingstylesheet]

No. This is one of the fallacies put forth by religious people that random atoms bumping together made life. That's not how chemistry works in general, and is an outright complete misrepresentation of organic chemistry in specific. Go take a year of chem majors O-chem, then you'll understand.

It's jus ta shorthand phrase.

Snarking doesn't solve the problem. It's still apparently unlikely enough that you haven't found it anywhere else.

Re:It's a Calculation problem

[drinkypoo]

I think it's not so absurd to think that it could have happened only a very few times in all the universe.

Planets capable of supporting life may well tend to produce it. Look at how our own planet produces periods of relative stasis only because life exists.

Re:It's a Calculation problem

[SuiteSisterMary]

This. It's within my own lifetime that scientists were pretty sure that no lifeforms could exist on Earth that weren't part of a solar foodchain. Surprise! We're finding life in all sorts of 'impossible' places right here.

You also get the supreme arrogance that is the assumption that we'd recognize signs of an alien civilization.

Take this thought experiment. What's the most recent decade that you could pluck a team of scientists, with fully stocked contemporary laboratories, put them in a sealed room, and have them wind up watching Netflix? That is to say, could a team of scientists, from 1990, with 1990s equipment, intercept, identify, decode, decrypt, reconstruct, and view a random Netflix stream that somebody a room over is watching on their smartphone over wi-fi? Could a team from the 1980s? The 1970s? 1960s? 1950s? 1940s?

Re:It's a Calculation problem

[Green Mountain Bot]

Which makes more sense?

A) Intelligent life is so unlikely to occur that humanity is the only example in all the universe; or
B) We (as well other intelligent life) aren't yet advanced enough to span the vast distances of space between us and whatever other intelligent life which inevitably came into/will come into existence.

The former requires something to have happened against odds so large the human brain can't even begin to grasp them - the scale of the universe undermines the argument. That doesn't mean that it's necessarily wrong, but it does mean that the odds of it being right are pretty close to the odds the argument itself requires be overcome for intelligent life to exist even on Earth.

Looking at it from an Occam's Razor perspective, the universe being so large that we haven't had the chance to run into other intelligent life is a much simpler answer than any hypothesis that would attempt to explain how intelligent life on earth managed to buck such incredibly stacked odds.

Re:It's a Calculation problem

[mark-t]

Given what we don't know about the universe, the only logically valid thing that we can say is that we simply don't know if there is other complex life out there or not... we cannot make any meaningful estimations of its actual probability of occurrence, even given the vastness of the universe, unless or until we encounter at least one other form of it. If we never do, we will never know. This makes the belief that we probably aren't alone in the universe an actually unfalsifiable premise, even if it weren't true.

Re:It's a Calculation problem

[Green Mountain Bot]

This makes the belief that we probably aren't alone in the universe an actually unfalsifiable premise, even if it weren't true.

In the sense that you can't prove a negative, sure. But the belief that we ARE alone *is* falsifiable - we just need one example to the contrary and it's proven false.

Re:It's a Calculation problem

[mark-t]

Of course its falsifiable... it's an eventually testable hypothesis, and I would therefore suggest it is the more worthy one to adopt.

And by the way, you can prove a negative... the Michelson-Morley experiment disproved the aether, for instance. To prove a negative, you only need an unambiguous implication of the existence of whatever you are wanting to disprove in an objectively measurable way.

The *only* proof that extraterrestrial complex life exists or is even necessarily likely is an example of it.

Re:It's a Calculation problem

[meglon]

No. Words have meaning. There's very little random about chemical reactions, especially complex organics. When someone suggests this as an argument, it is nothing more than a statement from them that they have no understanding of chemistry at all. Ignorant people should be learning about things, not trying to converse about things.

Re:It's a Calculation problem

[meglon]

No.

First off, evolution has nothing to do with the origins of life; that's abiogenesis (something religious people get confused from the get go).

There are reasons that certain elements go together, and certain molecules; it's not some random shooting gallery filled with billions of molecules.... it's directed by positive and negative charges, bonding strengths and angular tensions... among other things (and no, no "intelligence" needed for chemistry to happen). My suggestion to take a year of majors ochem is, simply put, the BASIC knowledge you'd have to acquire to start to understand organic chemistry.... something abiogenesis requires.

It's not snark, it's me pointing out that you're trying to make very broad generalizations about something you don't seem to know enough about. It's like people taking pseudo-science bullshit and putting "theory" behind it. That word has a specific meaning, and simply because they use it incredibly wrong doesn't elevate the bullshits it's being used with to actually being a theory.

Re:It's a Calculation problem

[meglon]

See, i still don't get how a bird and a bee's genetic code can do what they're claiming.... those have to be pretty disparate.

Re:It's a Calculation problem

[mentil]

They were more desperate than disparate, apparently.

The future!

[Anonymous Coward]

> "This is why we must preserve the light of consciousness by becoming a spacefaring civilization & extending life to other planets..."

QUICK! Do something. Well what the hell can we do in the face of light-year distances and utterly alien environments? I know, I know,... we should subsidize near-orbit launches using hydrocarbon fuels for bored billionaires. Let's call it innovation! Entrepreneurship! The future!

Re:The future!

[ath1901]

Extending life is easy, cheap and doable: Contaminate Mars and Venus.

Take samples from all reasonably cold resistant bacteria on earth and spray them all over Mars. Maybe something manages to grow there. Do the same for Venus with heat resistant bacteria.

If bacterial life gets a foothold, we might get more advanced life in just a few million years or so.

Re:The future!

[Green Mountain Bot]

Do the same for Venus with heat resistant bacteria.

Don't forget the immense atmospheric pressure and sulphuric acid rain.

Re:The future!

[ath1901]

I was thinking of the bacteria living near hydrothermal vents. I believe some of them use sulfur instead of oxygen so the sulfuric rain might be a good thing.

However, after looking up temperatures at wikipedia, the thermophile bacteria on earth can prosper up to 122C but Venus has a surface temperature of 462C so you would have to find a very very very cold place (relatively speaking) for them to thrive.

Out there might be the wrong place to look

[xtal]

http://brighterbrains.org/arti...

Based on the exponential rate of technological development, I'm guessing the actual answer to where everyone might be is likely some variant of this hypothesis.

Regardless, Elon is right.. Mars. Stat.

Re:Out there might be the wrong place to look

[JohnStock]

I've seen this argument before but for me there's one major flaw. If a society decides to evolve down in scale they inherently have less computing and storage power. You might argue back that at those small scales, they are more efficient. To which I'd respond that you can have your cake and eat it by having your computing at small scales all the way up to macro scales. A bit like a jupiter sized computer that works on the level of quarks or some such. The assumption being that computing and storage are important in a highly developed species.

Good statistics, but with questionable assumptions

[Anonymous Coward]

The authors do a nice job of pointing out the flawed methodology of many previous writers on the Drake equation, but continue to perpetuate the questionable assumptions that underlie it. Here are a couple for starters: First, why do we conflate "intelligent life" with "civilization"? For us, technological advance has been associated with growth in population and social structures, but intelligence could just as well arise in beings that live much longer than we do and do not feel the need (or perhaps are not even able) to reproduce by the millions. Think of the intelligent ocean on Lem's Solaris, for example. Second, we cannot begin to estimate "detectability" when we have no idea what to look for. Yes, we incessantly communicate and frequently use radio waves to do so, but neither might be true for a less social or less numerous intelligence. How would we detect a lifeform that abandoned its planet billions of years ago and now wanders the galaxy? As in so many discussions of extraterrestrial life, I see people who are looking only for something familiar and who wouldn't recognize something genuinely alien if it was right in front of them.

oblig xkcd

[religionofpeas]

https://xkcd.com/384/

For once a religion worthwhile pursuing.

[Qbertino]

"Keeping alive the light of consciousness and spreading if throughout the universe so that it won't die" seems to me for once like a religious imperative worth pursuing. It actually would keep people away from tribal bullshit and have us all work together.

Let's update our cults to that one. I'm all in for it. ... There is even the imperative to have and raise children in it - pretty much spot on a perfect upgrade to the abrahamic revelation cults if you ask me.

Re:For once a religion worthwhile pursuing.

[synaptik]

Sounds great, but I guaran-damn-tee that someone will twist it into something perverse and destructive. Like, "all consciousness is equal, but some are more equal than others."

At the very least, add something about not being racist, and overrunning available resources before sending out diaspora.

Re:For once a religion worthwhile pursuing.

[synaptik]

Sending frozen blastocysts out towards likely planets, to be incubated & mothered by robots upon successful arrival? That might work.

Re:For once a religion worthwhile pursuing.

[synaptik]

Life exists in the service of entropy. We hasten it.

We donâ(TM)t know

[tsa]

So the conclusion of the article is something weâ(TM)ve known since the beginning of mankind: we donâ(TM)t know if weâ(TM)re alone in the universe.
Not really worth writing about, is it?

Don't take Fermi's name in vain.

[Anonymous Coward]

I think it is wrong to always drag Fermi into these speculations. He was a scientist, and it was a valid question - but the discussion has moved on a great deal since 1950; he was also famous, which is why his names keeps popping up and is used as 'proof' that we are alone in the universe, which I'm sure he himself would have considered absurd.

With little evidence either way, this is at best speculation, and it is a course of speculation that has been running almost without change for decades - maybe even centuries. The best either side has been able to come up with, at least until very recently, is 'surely ...'.There is, however a growing body of evidence to suggest that at least primitive life may well be an inevitable consequence of physics and chemistry, and my bet is on the side of the same being the case for both complex life and intelligent life.

Life, and probably any complex, dynamic system in which evolution can take place, seem to evolve a steps, with life reaching a sort of quasi-stable state, until somewhere a major "innovation" (for lack of a better word) breaks the stability and rapidly takes over the scene, to the exclusion of any other, similar innovation. (I prefer the word 'innovation' over 'mutation' because I think these major steps mostly involve lucky combinations of mutations, that have accumulated over a longer period). An example of such an innovation would be the appearance of eukaryotes, and one thing that is worth bearing in mind is that it is perfectly possible that there could have been a large number of other, similar innovations at around that time, which just never got off the ground because they were outcompeted. It could be that elsewhere there are 'higher' lifeforms based on a kind of highly optimised biofilms, where similar advantages to the eukaryotes were realised, but without endosymbiosis - after all, why not?

After that, it seems almost obvious that multicellular life and then intelligence must evolve: biofilms are already to some extent organised and cooperating about resources. There would appear to be a continuum from biofilms to simple, multicellular lifeforms - and multicellular life leads to cell-specialisation and a growing need for organisation and coordination - things like muscle cells and nerve cells almost have to follow at some point, and in time, intelligence. Not because of some "plan", but because these developments keep giving adaptive advantages. Intelligence, as I think the scientific consensus is now, is also a matter of degrees - there is no sharp cut-off point, where humans suddenly became self-aware and intelligent.

So where is everybody? If we think of our ouwn technological level, and how quickly we have gone from messengers on rapid horses to the global internet and radio communication, and compare that to interstellar distances, I don't think it is surprising that we don't see anything of other civilisations - would we be able to see, simply by chance, a radio signal from even the nearest star system? Would we even be able to detect a radio signal if we knew it had to be there, and it was directed straight at us? And how far away would we be able to? And if it turns out that we can, the stars are mostly so far away, that any signal would still be on its way to us, since we are limited by the speed of light. And if it is posssible to go beyong light-speed, we still don't know how to detect such a signal. All in all, I think it is obvious why we haven't seen or heard anything from other civilisations.

If we *are* alone

[MrKaos]

then it's as equally terrifying as if we aren't alone.

Re:If we *are* alone

[Anonymous Coward]

What's so terrifying about humanity being alone in the universe?

Re: With morons like Trump "running things"

[Pitt64]

sorry, humans cant live in radiation sorry, again

So what?

[NerdENerd]

We haven't detected any radio waves, so what? Look at most life on earth and think how likely is it that they will develop a radio telescope? Very fucking unlikely! Sharks have cruised our oceans for hundreds of millions of years pretty much unchanged, are they going to ever produce a radio telescope? Note very likely. Dolphins, apes, elephants and ravens are all incredibly intelligent species that don't look like cracking the radio telescope project anytime soon. Even most pockets of human existence were not looking like having any major technological break through anytime soon from Australian Aboriginals, pygmy rain forest tribes, Kalahari Bush Men or Papua tribes men. It seems the survive the long harsh winter of Europe was the anonymity that led to major technological break throughs so I see no reason why the galaxy or at least the universe if not our local neighbourhood can't be filled with highly evolved conscious beings that just never made a radio telescope. Basing our conclusions on we haven't detected anything yet is just plain ridiculous.

Re:So what?

[Green Mountain Bot]

Dolphins, apes, elephants and ravens are all incredibly intelligent species that don't look like cracking the radio telescope project anytime soon.

In fact, it was apes who invented the radio telescope, and it is apes who continue to operate them, and to innovate new forms of them.

Re:So what?

[quenda]

> the long harsh winter of Europe ... led to major technological break throughs

Colder climates are associated with higher average intelligence, but not with historical breakthroughs.
Mesopotamia, Egypt, Indus valley, Greece ... not exactly snowbound.
The cold places were sparsely populated with barbarians such as Mongols and vikings. Not known for science and technology until the last few centuries, starting with England.

Re:With morons like Trump "running things"

[Anonymous Coward]

The problem with this "study" is that it's closed minded.

The universe is still young by cosmological scales. Why do they assume that extraterrestrial life has to be zipping around the universe building Dyson spheres and shit? How do they know that there isn't life elsewhere that is less advanced than us, as advanced as us or more advanced but not starfaring?

Also, I thought Elon Musk firmly believed that the whole of existence is a simulation. If that's the case, then instead of spreading out into the universe, why don't we work on building our own simulation too and move into it where we would have complete control and mastery over everything?

humans are alone in the "observable" universe

[PolygamousRanchKid]

That we have basically no measurement of any of this data means it is impossible to use the supposed equation of The Fermi Paradox to determine anything at all.

I totally agree . . . what about the "non-observable" universe . . . ?

There could be critters composed of Dark Energy, living on Dark Matter out there.

We cannot see them, because "they" do not want us to.

That a paper from Oxford uses it is, one would hope, a joke from a couple drunk frat students hoping to get an easily published paper out to boos their careers.

I think the the paper is intentional disinformation, written by critters composed of Dark Energy, living on Dark Matter.

They want to convince us that we should not go out looking for them, because they think that humans would find them very tasty.

Yum-yum.

Re:With morons like Trump "running things"

[Joce640k]

"starfaring" may be impossible in practice.

Should we move to Mars? It will be very expensive and mostly pointless.

How about we spend all that money looking after the place where conditions are suitable and we know we can survive?

New meglon study says...

[meglon]

We don't have to worry about LGM's (little green men), but we do have to watch out for the LGM's (large green motherfuckers).

Look Closer

[mentil]

There could be plenty of microbial life out there, which came into being independent of life on Earth (i.e. no common panspermia source, if applicable) that we'd never be able to detect via looking for alien spacecraft or radio emissions. Considering how many billions of years life on Earth was limited to single-celled microbes, it's plausible that conditions on some bodies wouldn't be suitable for macroscopic life. Even if microbial, this would have major philosophical/religious implications.
Intelligent life would be cool, due to cultural exchange, but there wouldn't necessarily be any additional implications about the meaning of human existence.

So far, we've sent quite a few landers to Mars, and have acquired an increasing amount of evidence that chemicals that can produce known forms of life are/were present. So we haven't even completely rendered it implausible that microbial life could've once existed on one of the most-studied bodies in our solar system. It's supremely naive and premature to use current data to make any conclusions about such easily-missed details in the universe.

Don't give up

[Anonymous Coward]

How about we spend all that money looking after the place where conditions are suitable and we know we can survive?

Long term living on Earth won't work for us. Eventually an asteroid big enough will hit, statistically speaking.

If we never accomplish interstellar travel, then in 5 billion years we die with our Sun's expansion. If we can travel a bit, then we can last perhaps 10^100 years orbiting a supermassive blackhole into the heatdeath of the Universe.

In the short term, like the amount of time to the next election, none of this is of any significance.

Re:Don't give up

[Joce640k]

If an Asteroid decides to come this way then we can't do much about it.

A few colonists on Mars won't make any difference - they'll be dependent on Earth to resupply them with stuff even if they're making their own water and potatoes.

If we never accomplish interstellar travel, then in 5 billion years we die with our Sun's expansion

Correct, but even 1 thousand more years of living at the current rate of destruction isn't going to work out either so that's not much of a concern.

Re:Don't give up

[religionofpeas]

If we never accomplish interstellar travel, then in 5 billion years we die with our Sun's expansion.

It makes no sense to refer to our descendants 5 billion years from now, as "we", let alone worry about their fate.

Re:Don't give up

[Anonymous Coward]

The renowned cosmogonist Professor Bignumska, lecturing on the future of the universe, had just stated that in about a billion years, according to her calculations, the earth would fall into the sun in a fiery death.

In the back of the auditorium a tremulous voice piped up: "Excuse me, Professor, but how long did you say it would be?"

Professor Bignumska calmly replied, "About a billion years."

A sigh of relief was heard. "Whew! for a minute there, I thought you said million years!"

Re:Don't give up

[umghhh]

I feel with you but calling things we do a destruction is very anthropocentric. After all, this is all, that all forms of life do - move the boundaries as far as they can. The pristine empty countryside was thus destroyed by the invading plants from the sea first and then to make things worse the fish has followed. What you possibly mean is that we have reached the boundary - this we can only know from behind it. So far we have always managed to extend it and survive local collapse even if local meant half of the world (Toba explosion ~70kya for instance). I am not such a big fan of going to Mars but if a colony can be established it can also reach point of self sustainability. There is a point in another statement about interstellar travel i.e. that it very well be impossible or at least with the means we have now it is.

Re: Don't give up

[Anonymous Coward]

Yeah, fuck them, we want ours.

People like you are the problem with humanity.

Re:Don't give up

[Immerman]

In fairness, if we have the technology to effectively colonize Mars, then deflecting an "planet-killer" asteroid should be fairly trivial. And if we're able to travel between stars at even a few percentage of light speed, then it's probably easy enough to just keep moving the Earth further from the sun to maintain a pleasant environment - some size large ion drives on the moon, firing for several million years, should tow the Earth along just fine.

Of course, once you've done that it's not such a stretch to put some size-large lights on the moon as well, to illuminate the Earth in lieu of the sun, and head into interstellar space. With the aid of some mildly efficient mass-energy conversion the moon should provide plenty of power for the journey. The real question is, do all the terraformed planets head to the same star, or do we scatter in all directions?

Re:Don't give up

[Immerman]

I'm not sure it's all that antropocentric to call it destruction, when of all life on Earth we will be among those to die last. We're omnivores at the top of the food chain - we won't die out until there's no other life left to eat.

And while other forms of life do indeed push beyond existing boundaries, we're fairly unique in the sheer scale and effectiveness of the destruction we can wreak on other life. The only other species I can think of that has demonstrated anything similar was the blue-green algae that first wiped out most life on the planet by poisoning it with toxic free oxygen.

Re:Don't give up

[Immerman]

I bet you don't consider our rodent-like ancestors "we" either, do you? To say nothing of the primordial slime that started everything off.

That's fine, just don't try to project your own small-mindedness on everyone else.

Re:Don't give up

[bobschmagogee]

Exactly. Being in my 40s, I'm only concerned with the next 40-50 years or so (assuming I live that long). Everything after that is no longer my problem.

Re: Don't give up

[xtal]

It is trivial to deflect an asteroid (and maybe even a comet) now, with todayâ(TM)s tech, provided we are looking.

We arenâ(TM)t looking.

Re:Don't give up

[Cajun Hell]

Long term living on Earth won't work for us. Eventually an asteroid big enough will hit, statistically speaking.

Asteroids hitting us and wiping us out doesn't need to be a good answer; it just needs to be the best answer. It might be that for all planets everywhere in the universe, waiting for a killer asteroid is easier than colonizing other worlds.

Re: Don't give up

[Cajun Hell]

People like you are the problem with humanity.

Why are you singling out humanity? I don't hear any dogs or trees or paramecia saying they look at the situation any differently.

Re:Don't give up

[ravenshrike]

The issue isn't deflecting the asteroids given warning, the issue is being able to see the asteroids in time to give said warning.

Re:Don't give up

[Areyoukiddingme]

If an Asteroid decides to come this way then we can't do much about it.

If an asteroid decides to come this way, we're not alone in the universe.

Never anthropomorphize asteroids. They hate that.

Re: Don't give up

[Immerman]

Actually we are looking, just not very well. But we're also developing telescope arrays specifically for the task, which should improve the situation by several orders of magnitude.

Deflecting such an asteroid though is far from trivial though. Hitting it with nukes is an extremely dangerous idea, as it runs the risk of breaking it up into a cloud of shrapnel that could do even greater damage. Landing on a chaotically tumbling rock a few miles across is also a non-trivial exercise - though if managed to land a BFR, flip it on it's nose, and fire the engines briefly when thefacing in the right direction we could probably push it off course - assuming we spotted it with enough time to spare. And didn't tear the thing apart into a cloud of shrapnel in the process.

Basically we have lots of untested ideas, but won't know if any of them are viable until we start testing them. It'd be nice if our first test wasn't in the face of the imminent destruction of most life on Earth.

Re:Don't give up

[Immerman]

It's both, really. We absolutely need to spot the things first, but then we have to figure out how to deflect them. Currently we don't really have a lot of ideas that wouldn't require intercepting said asteroid in the outer solar system to have a good chance of success, and we don't have any way to reach the outer solar system on short notice.

Re:Don't give up

[l0ungeb0y]

Spoken like a true American. "I got mine, fuck everyone else".
You can collect your free MAGA cap on the way out

Re:Don't give up

[Tough Love]

Long term living on Earth won't work for us. Eventually an asteroid big enough will hit, statistically speaking.

By that time, we won't be fragile bags of meat and bones, we will be robust, distributed organisms easily able to survive a few million years of asteroid winter. That is, if Trump does not wipe us out first.

Re:Don't give up

[twosat]

What if other intelligent life exists but can't stand us and actively hides from us? "They're made out of Meat" by Terry Bisson.

Short film based on the short story: https://www.youtube.com/watch?...
Youtube clip using the original full text: https://www.youtube.com/watch?...

Re:Don't give up

[stoatwblr]

"We're omnivores at the top of the food chain - we won't die out until there's no other life left to eat."

We may be omnivores, but we have extremely oxygen-hungry brains.

The most likely planetary event in the near future is an anoxic event - caused by us - and we're likely to be the first major casualty of it.

There's only one ethnic group that can handle a long-term reduction in sea-level oxygen concentration to 17% or below and they currently mostly live above 8000 feet - Tibetans/Nepalese(*). Even then they'd have to move to sea level and I suspect that as half our atmospheric oxygen comes from the oceans there's a good chance that the percentage may go below 15%, which even that population would have trouble coping with.

30 years ago someone postulated that in 50,000 years our descendants would probably be oxygen starved apes living in coastal swamps covering what remained of our cities. That hypothesis may well be right.

On the bright side, an anoxic event would eventually take out most critters larger than about 25kg, and anoxic events lay down oil deposits - which means that in about 60 million years another intelligent species might evolve have a chance to try for spaceflight again.

(*) Humans (and most primates) cope with reduced oxygen levels by thickening their blood coupled with vasodilation. This works as a temporary measure but the (not very) long term effect is congestive pulmonary failure due to the extra pumping load (High altitude pulmonary oedema (HAPE) - which can come on after only a few days, along with high altitude cerebral edema (HACE)). The two groups above have a genetic variant which increases the oxygen carrying capacity of their blood without making it harder to circulate.

Re:Don't give up

[stoatwblr]

"It makes no sense to refer to our descendants 5 billion years from now, as "we", let alone worry about their fate."

It makes no sense to consider that we would have decendants on _this_ planet 5 billion years from now.

In around 500 million years the sun will have become hot enough that earth will be too hot for life to exist here (except maybe deep underground). It's already 50% brighter than it was 500 million years ago.

Re: Don't give up

[stoatwblr]

"Actually we are looking, just not very well."

It's hard to see things coming towards us from the direction of the asteroid belt - and virtually impossible to see them when they're coming from the direction of the sun. Almost everything orbiting can be described as "blacker than a black cat in a coal mine at midnight", so we tend to only see them as they whip past.

Re:Don't give up

[stoatwblr]

In most cases, knowing where an asteroid will hit means that the best policy will be evacuation/preparedness.

Breaking an asteroid or comet up may actually be _worse_ than having a single impactor, especially for glancing blows - a chap named "craterhunter" has been researching the hypothesis that an airbursting fragmented comet was responsible for sterilising most of North American circa 10k years ago and triggering the Younger Dryas, without leaving much in the way of impact craters. Simulating what happens when multiple fragments hit the upper atmosphere tends to support his idea that they effectively punch a plasma fireball to the ground in a similar matter to the way a shaped charge HEAT round penetrates tank armour.

Re: Don't give up

[Immerman]

The moon is likewise blacker than coal, but like asteroids coming from outside our orbit, reflected sunlight makes them all stand out against the near absolute blackness of space quite well - IF you're looking carefully in the exact location they're at, over a period of days or weeks so that their motion can be detected against the background noise of the camera. If they're coming from too near the sun then yes, they're hard to detect - back-lit coal in a vacuum is very hard to see. On the bright side (hyuck hyuck), that almost doesn't matter - nothing is coming at us from the direction of the sun unless it first fell in from beyond our orbit, where it would have been visible. Even something that screams through the inner system like Halley's comet takes about 20 years to get from Neptune's orbit to Earth's. Plenty of time to spot it opposite from the sun and characterize its orbit before it gets anywhere close to us. Even something from way out in the Oort cloud take several years to cross that distance.

Of course - there's a lot of sky to cover really frequently, which is why there are several proposals for wide-angle telescope arrays designed specifically for the job.

The real sneaky asteroids are our "pseudomoons" - the asteroids that share our orbit and migrate between Earth and our L4 and L5 points, about 60 degrees in either direction from Earth. Except during a near pass, they're virtually invisible from earth, showing only a tiny crescent of illuminated surface. Fortunately that's entirely a limitation of our own position - a telescope looking outwards from closer to the sun could spot them easily.

Re:Don't give up

[Immerman]

We're nowhere close to having the technology to effectively colonize Mars - we might be able to establish an outpost within the next decade or two, but it'll probably take at least a century or two before it grows into a truly self-supporting colony - and that's assuming we're willing to maintain a lifeline from Earth for all that time. And considerably longer than that until "Mars is colonized", rather than just "We've established a few colonies on Mars". It is a whole freaking planet after all, with a surface area roughly equal to the entire land area of Earth. Just as England did not effectively colonize North America with the founding of Roanoke.

Re:Don't give up

[Immerman]

That is certainly possible - and unfortunately the low oxygen itself won't be the problem. The real problem will be that to get to that point we will have disrupted the oceanic algae, allowing their hydrgen-sulfide producing cousins to become dominant. And hydrogen sulfide does strange things to mammals, inducing a hibernation like state in high concentrations, and slowing their metabolism to a pseudo-reptilian state at lower concentrations - incapable of supporting the comparatively large brains so common in mammals. We'll likely survive, every mammal species on the planet is descended from the survivors of several HS events, but an HS-rich atmosphere causes severe brain damage, robbing us of the intellect that gives us such a profound advantage. On the bright side, any trace of civilization surviving in eco-domes won't have to worry about inbreeding - the outsiders may be little more than animals, but they'll still be genetically human, and any children birthed and raised in a normal atmosphere should develop normally. And once the HS event is over the next generation will have human intelligence again (minus any losses to selective breeding for more immediately useful attributes)

Re:Don't give up

[kenwd0elq]

"If an Asteroid decides to come this way then we can't do much about it. A few colonists on Mars won't make any difference -"

Developing the technology to travel to Mars, and to build colonies there, will help us to develop the technology that will allow us to catch such asteroids. We don't want to destroy them; they'll be more useful as raw materials for space habitats. Even if interstellar travel proves to be impossible (which I do not believe), we can develop a number of places where people can live right here in THIS solar system.

And in the far distant future, we'll be able, as the Sun expands into a red giant, to move the Earth to a more comfortable distance out from our star.

Re:Don't give up

[kenwd0elq]

"the earth would fall into the sun in a fiery death."

Perhaps I'm being nitpicky, but this will not happen. The Sun will, at some point, expand to consume the Earth, which is perhaps a difference without much of a distinction. But if the human race (or some successor race after us) exists at that time, we should have the ability to move the Earth out to a more comfortable distance. We already know HOW; we just don't have the technology - YET.

Re:Don't give up

[Joce640k]

The universe is all just one big chemical reaction that started at the Big Bang, including your "thoughts".

What makes you believe you can change the course of the universe more than an asteroid? Do you have more free will than the rock?

Re:Don't give up

[Immerman]

That's what the lights on the moon are for, to replace the input from the sun. Output needs only be an infinitesimal fraction of that of the sun, since only an infinitesimal fraction of the sun's output reaches Earth.

Total solar input to Earth's upper atmosphere ~= 1368W/m^2 * pi*(*3.6*10^6m^2) = 5.6*10^16W
and by e=mc^2, 1kg = ~9*10^16 Ws
So, with mass-energy conversion we'd need to consume about 0.6 kg/second of mass, or ~20 million kg/year
And the mass of the moon is 7.3*10^22 kilograms, so it would provide sufficient energy for 3.7*10^15 years

Just to put that in proper perspective, the current age of the universe is only ~14*10^9 years, so the moon's mass could support a sun-grade input to the Earth for a million times the age of the universe. Of course mass-energy conversion is unlikely to be 100% efficient, but with those kinds of numbers even 0.000001% efficiency would be plenty to cross between stars.

Granted, we couldn't hope to do such a thing today, but in a hundred million years from now? 12,000 years ago we were still in the stone age - where will be after 10,000x as long?

Re:Don't give up

[RockDoctor]

Would you like to attend the next training course I run on H2S safety? I need a new sacrificial lamb after my last one died. Well, "was sacrificied". For some reason, the farmer thinks the way I kill them is cruel and sends them to the slaughterhouse instead.

The boundary between significant neurological consequences (I've known people with such brain damage. It's not pretty.) and rapid death is quite narrow - a factor of 3 in concentration, less if the victim loses motor control. Getting an atmosphere that well mixed is quite hard if you're doing it from localised sources (eg anoxic basins in the deep oceans).

Re:Don't give up

[Immerman]

As I recall it's not from deep ocean basins, but red surface algae that displaces the normal blue-green variety over some unknown period of time. It should mix into the atmosphere just fine. Maybe stay away from the coasts. Our ancestors survived several such events, there's a good chance that the genes that made it possible still linger in at least some of the population.

TFA makes interesting points

[bradley13]

I only skimmed TFA, but the points it makes are interesting. The Drake equation is well known - multiply the probabilities of all the factors required for a civilization. The interesting point is this: those probabilities have ranges, in many cases with a lower bound of zero. In the absence of knowledge, if you actually randomly choose values from the entire range, then odds are good that at least one of the parameters will be close to zero - thus giving you an empty universe.

Of course, our real goal should be to improve our knowledge. As it is, even TFA is purest speculation.

Re:TFA makes interesting points

[religionofpeas]

Instead of multiplying the probably with the total number of stars, we should multiply each probability with the inverse square distance of the star, and then integrate over the universe.

The square distance is a decent measure of detectability.

Re:TFA makes interesting points

[Green Mountain Bot]

In the absence of knowledge, if you actually randomly choose values from the entire range, then odds are good that at least one of the parameters will be close to zero - thus giving you an empty universe.

How's that? And how do you justify randomly choosing values from the entire range? Also, "close to zero" in terms of the Drake equation is nowhere near the same thing as "zero", given the number of stars in the universe. It doesn't take a very large number at all to get to "more intelligent life than just earth".

Elon hasn't heard about Space ISIS?

[h33t l4x0r]

They're out there, folks, believe me. That's why we need Space Force. Space Force will stop them.

Seems Appropriate...

[Mister Transistor]

You are a fluke of the universe. You have no right to be here.
Deteriorata. Deteriorata.

Go placidly amid the noise and waste,
And remember what comfort there may be in owning a piece thereof.
Avoid quiet and passive persons, unless you are in need of sleep.
Rotate your tires.
Speak glowingly of those greater than yourself,
And heed well their advice, even though they be turkeys.
Know what to kiss, and when.
Consider that two wrongs never make a right, but that three do.
Wherever possible, put people on hold.
Be comforted that in the face of all aridity and disillusionment,
and despite the changing fortunes of time,
There is always a big future in computer maintenance.

Remember The Pueblo.
Strive at all times to bend, fold, spindle, and mutilate.
Know yourself. If you need help, call the FBI.
Exercise caution in your daily affairs,
Especially with those persons closest to you -
That lemon on your left, for instance.
Be assured that a walk through the ocean of most souls
Would scarcely get your feet wet.
Fall not in love therefore. It will stick to your face.
Gracefully surrender the things of youth: birds, clean air, tuna, Taiwan.
And let not the sands of time get in your lunch.
Hire people with hooks.
For a good time, call 606-4311. Ask for Ken.
Take heart in the bedeepening gloom
That your dog is finally getting enough cheese.
And reflect that whatever fortune may be your lot,
It could only be worse in Milwaukee.

You are a fluke of the universe.
You have no right to be here.
And whether you can hear it or not,
The universe is laughing behind your back.

Therefore, make peace with your god,
Whatever you perceive him to be - hairy thunderer, or cosmic muffin.
With all its hopes, dreams, promises, and urban renewal,
The world continues to deteriorate.
Give up!

"Deteriorata" - National Lampoon

Good news

[TomGreenhaw]

As much as its nice to think that ET might come here with magic to wash away all our troubles, the fact is we wouldn't react to it well. Even if ET tried, those mentally ill and greedy among us would use their blessings to subvert the benefits

In all likelihood, ET would not care to preserve us and contact with ET would not be good for us.

Given the possibilities, we are better off alone until our society evolves to control the megalomaniacs.

Re:Good news

[ath1901]

It's not ET. It's Kleeborp the Retard:
https://www.youtube.com/watch?...

I think the clip has more insight into the question of space aliens than we would like.

The chances of anything coming from Mars...

[gnalre]

...are grossly overestimated he said

The problem with the Drake equation is it tends to look at the problem from a physicist/astrophysics point of view. if you look from a biological perspective, things become even murkier.

1. We still have no understanding how life appeared on earth. yes we can propose a mechanism for the creation of amino acids, but that is a long way to creating even basic life
2. We have no way of calculating the likelihood of creating complex life. On earth this appears to go go back to one event during symbiogenesis. How likely is this to happen? How often has it happened since then, but the organisms did not survive
3. What we term intelligent life (insert joke here) has only appeared as far as we can tell once in 4.5 billion years. Why is this? What are the conditions needed and why has it not happened in multiple times

Personally I think the possibility of single cell life arising quite likely given the right conditions, but multi-cell intelligent life highly unlikely. Fortunately the universe is quite large so even very low probability events come about if your allowed to roll the dice enough, but the likelihood of it happening twice in the same neighborhood is so low, to be virtually non-existent

Re:The chances of anything coming from Mars...

[Green Mountain Bot]

3. What we term intelligent life (insert joke here) has only appeared as far as we can tell once in 4.5 billion years. Why is this?

Because what "we can tell" is not even close to authoritative knowledge. We only started verifying the existence of extrasolar planets in the last 23 years.

What are the conditions needed and why has it not happened in multiple times?

We don't know the answer to the former, and the latter is a loaded question. We have no idea whether or not it has happened more than once. But given the sheer immensity of the universe, it seems highly unlikely that ANY phenomenon exists only in one place.

Chances

[JustOK]

The odds that there is other life is 50/50: Either there is or there isn't.

Re:Chances

[Anonymous Coward]

> The odds that there is other life is 50/50: Either there is or there isn't.

What are the odds that you failed probability?

Re:Chances

[religionofpeas]

And if I buy a lottery ticket, it's either the $10-million winning ticket, or it isn't.

Re:Chances

[JustOK]

Blue tulip

Making the Universe Great Again

[t4eXanadu]

Or maybe aliens built a giant unseen wall around our part of the universe to keep us from immigrating to other worlds. . Call it The Great Filter if you will. The aliens heard humans are a bunch of rapists and thugs, and they don't want us infesting other worlds. Make the Universe Great Again!

But they keep getting stuck

[kilodelta]

On the Fermi Paradox when the Drake Equation - more of the variables in that one are getting filled in all the time. Last pass at it shows at a minimum 10,000 possible intelligent species out there in the universe. It's just the distances between us and them is mind boggling long.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:With morons like Trump "running things"

[Oswald McWeany]

Should we move to Mars? It will be very expensive and mostly pointless.

How about we spend all that money looking after the place where conditions are suitable and we know we can survive?

Why not both? It certainly isn't "pointless" to want to expand the human condition and strive to create a backup for earth and all life as we know it.

It's not an either/or scenario. No-one is talking about moving the entire human population to mars- that would defeat the purpose. We can try to restore earth and maintain a population on Earth, which will always be the most suitable place for human habitation AND at the same time expand into the solar system- starting with Mars.

There's a lot of empty space in the Universe. Let's fill it up. Proxima 3 needs a Starbucks.

Galactic star hoping ...

[Martin S.]

While star hoping within the Milky Way is beyond our current technology and engineering, it does seem plausible with generational ships. What we know about physics and the limits imposed by c, suggest that travelling between Galaxies is not.

Lack of evidence isnâ(TM)t necessarily eviden

[Tangential]

Just because we havenâ(TM)t seen it, doesnâ(TM)t mean it isnâ(TM)t there.

That being said, perhaps every time âintelligentâ(TM) life develops and becomes more and more (vulnerably) dependent on technology it ultimately either wipes itself out or nature comes along and does it. Look how vulnerable we are now to something as simple as a large solar storm. Wipe out the solid state circuitry on this planet and see how long we last (as intelligent life.)

First perhaps?

[prisoner-of-enigma]

The following possibilities exist:

1. We are alone in the universe and will remain so forever.
2. We are not alone in the universe, being preceded by one or more civilizations.
3. We are alone in the universe at this time but conditions exist for other civilizations to evolve in due time.

Given the vast size and diversity of the universe, #1 seems almost ludicrous absent the intervention of some higher power (i.e. "Intelligent Design"). We occupy a rather mundane planet orbiting a ordinary star in a humdrum galaxy in no particularly special region of the universe. There's no reason to suspect there aren't trillions of other planets just like ours in this galaxy alone, let alone the trillions of galaxies beyond ours. If similar planets exist in similar conditions with similar age there's no reason for life not to have evolved on its own assuming life is a purely accidental event.

Possibility #2 makes more sense assuming humans aren't some special snowflake in the universe like #1 supposes. Humans have evolved and gone from squatting in caves to sending space probes into interstellar space in just a few thousand years. That's a fraction of an eyeblink of cosmological time. If another civilization developed just 10,000 years earlier than us -- again, something less than a rounding error in cosmological time -- imagine how far ahead of us they could be technologically. Imagine where we'll be in 10,000 years given our current exponential rate of progress.

Possibility #3 is a variation on #2 but backwards. Assuming more than one civilization will ever come into being in this universe, somebody has to be first to get there barring a fantastical coincidence. Perhaps we're it. If so, we are alone for now but unlikely to remain so over cosmological time scales.

Re:First perhaps?

[Attila Dimedici]

Of your three possibilities, only #1 is a scientific hypothesis because it is the only one of them which is falsifiable.

Re:First perhaps?

[Impy the Impiuos Imp]

One need only find evidence of another civilization to prove 2.

Re:First perhaps?

[HiThere]

Sorry, but there are various reasonable hypothesis that would make the Earth a quite rare kind of planet.

E.g., perhaps it's necessary that early in the evolution of the planet it be hit by such a large impactor that the continental plate is fractured into multiple tectonic plates and also yielding a large moon that will keep the mantel layer stirred up. I don't know that this is true, but it *might* be true.

There are multiple other reasons that the Earth may have experienced a crucial event in its history that was essential to the development of multicellular life. None of them are certain, but also none are totally implausible.

I think given multicellular life intelligence was inevitable, but I'm not as certain of language. Also may forms of life are less adaptable to life outside a small range of conditions than are humans. This may go back to climate changes that were happening about the time the hominids were differentiating. While it's true that humans are not the only invasive species, there are a very large number of species that aren't. If one of those became intelligent, it's path of development would be very different from ours. They might be either very demanding environmentalists, or they might swing totally towards artificial control over all aspects of the environment, but they'd certainly be different. E.g., it might cause them enough problems in spreading that they never developed races, because technological transportation capabilities kept groups from being isolated.

Please note that NONE of this is necessarily true, but also none is false. You can't rightfully assume either that there's nothing unusual about the Earth, or that the Earth is special and rare. There are too many unknowns.

Re:First perhaps?

[Attila Dimedici]

You do not prove a scientific hypothesis. You fail to falsify it.

Finding evidence of another civilization wis one of the many ways in which hypothesis 1 can be falsified. Please provide me with what evidence would prove 2 or 3 false?

Re:First perhaps?

[prisoner-of-enigma]

perhaps it's necessary that early in the evolution of the planet it be hit by such a large impactor that the continental plate is fractured into multiple tectonic plates and also yielding a large moon that will keep the mantel layer stirred up.

On a cosmological scale, such "rare" events turn out to be not so rare as you'd think. The likelihood of an event so rare as to make Earth unique is so statistically improbable that it begins to resemble divine intervention. Note I'm not attempting to make the case for or against divine intervention. I'm simply saying anything rare enough to make Earth a unique case would be indistinguishable from a "hand of God" kind of event. Such a rare event would have to happen only twice to make us not alone in the Universe and thus disprove conjecture #1. The odds against it would be staggering beyond belief or comprehension without some kind of divine intervention.

Re:First perhaps?

[prisoner-of-enigma]

Of your three possibilities, only #1 is a scientific hypothesis because it is the only one of them which is falsifiable.

I never postulated any of the three were scientific hypotheses, only that there are only three possible permutations. If you want to choose a point-in-time scenario, there are only two, namely:

1. We are alone in the universe at this time.
2. We are not alone in the universe at this time.

Re:First perhaps?

[HiThere]

It might not make "really earth link" quite that rare, but something that would reduce the likelihood of any particular solar system holding an earthlike planet by, say, a factor of 10,000 would make it quite likely that there wouldn't be one close enough to find.

OTOH, I am a strong believer in "macrolife", i.e. space habitats that roam about at considerably sub-C speeds, and don't really have any destination except "the next good pocket of resources". But since such groups would only move about a little faster than the average rate at which the dust drifts, for reasons of safety, they would not likely be in the neighborhood. When they hit a new solar system some would turn sessile, but others would just reproduce and send off several new groups. We know that the first kind hasn't settled here, because we'd have noticed them by now, but the second kind could have come and gone, and we wouldn't notice until we started mining the moons of the outer planets, or possibly the Oort cloud.

FWIW, they wouldn't be interested in a Earthlike planet even if they had the same conception of what that meant, because any planet that evolves life will be full of allergens that they haven't evolved to cope with, and if they're just going to live in shells, they've already got better ones that they're already living in, and with their's they can even adjust the gravity to suit themselves. (And without life it won't be very Earthlike.)

excellent

[cascadingstylesheet]

More planets for us.

Re:With morons like Trump "running things"

[GameboyRMH]

"starfaring" may be impossible in practice.

Indeed, our current understanding of the laws of physics says it pretty much is. Pushing stuff from A to B is practically a nonstarter. A generation ship is perhaps a theoretical exception, but it will take a big chunk of Earth's resources and is unlikely to reach its destination given all the things that could go wrong with the equipment or crew on the way which could doom the ship. Generation ships might only make sense as emergency lifeboats for when nature, or more likely man, finally puts a hard expiry date on Earth's habitability.

The closest humanity might realistically come to "starfaring" is to have a few outposts throughout the solar system that only need minimal resupply from Earth. Then if our planet gets totally fucked up by an asteroid or conservative environmental policy, it can be used as a factory/mining outpost to resupply the others.

Only 1 inhabitable planet exists.

[_bug_]

And it's Earth.

Which is what a lot of people thought up until very recently where we now have dozens known to us and the potential for many, many more to be discovered.

We didn't have data to prove otherwise, so we viewed Earth as unique. Now we have data and Earth is proving to be far from unique.

I think how we view the potential for "life" to exist "out there", in whatever form you want to consider life to be, will follow a similar path.

We have data

[sjbe]

The Fermi Paradox is an utterly useless test. It takes variables you have no data on and then says to compute their probability.

We do have data. Quite a lot of it actually. So far all the data we have has not given any indication of life anywhere but on Earth but it is data all the same. Now the universe is a big place and we've only looked at a tiny bit of it so far but to say we have no data is simply not true.

Re:We have data

[drinkypoo]

So far all the data we have has not given any indication of life anywhere but on Earth but it is data all the same.

It is data, but it is wholly irrelevant to the question. We can detect planets, but can't tell if they support life or not from here. We can only take a good guess at whether they support an industrialized society with radio communications. While I personally believe that the most likely explanation is that any so-called intelligent life wipes itself out before it achieves a much higher level of technology than what we're dealing with, it's also possible that the period of using radio communications is very brief (as such time spans are measured, anyhow) and intelligent species move away from RF in short order — maybe they find out cellphones cause cancer, or interfere with telepathy or something.

Re:With morons like Trump "running things"

[Wycliffe]

Generation ships might only make sense as emergency lifeboats for when nature, or more likely man, finally puts a hard expiry date on Earth's habitability.

The problem with this approach is that any event that puts a hard expiration on earth's habitability will likely make the building of a generational ship virtually impossible. Not to mention the politics of only a few people allowed to be on it. Just like life insurance or a loan, your best bet is to get it before you need it. Right now we have the technology and excess resources and manpower to build a generational ship. After we fall, we will likely not have the resources or even the organizational structure to build such a thing.

Circular reasoning

[sjbe]

First, there are no physics barriers to visiting other stars, purely engineering ones.

Engineering is applied physics so that statement is something of a tautology.

Second, many stars are relatively close together.

That statement is true in a sense but misleading. The fastest spacecraft we have ever launched will take tens of thousands of years to travel even the 4.3 light years to our nearest star. "Close" when you are talking about distances between stars is in reality still an almost unimaginably vast distance so close isn't really very close.

We see no attempts by anyone to apparently communicate with other civilizations

That seems like circular reasoning. You are saying we don't have evidence of other civilizations because we don't have evidence of them trying to communicate with each other. But since such evidence would constitute proof of their existence your reasoning seems to circle back on itself unless I misunderstand where you are going with this argument.

We also see no signs of any sort of megastructures like Ring Worlds and Dyson Spheres.

Why should we? We have no evidence or credible physics theory that such a structure is actually physically possible in real life. Heck, where would one get enough material to create such a structure? You could strip every planet in our solar system of every useful molecule and you still wouldn't have enough material to surround our star with a ring much less a sphere. Just because we can imagine something doesn't mean it's possible in the universe we actually live in.

Re:Circular reasoning

[Junta]

Also, even if you could build such structures, would it be a practical thing to do?

Re:Circular reasoning

[painandgreed]

Also, even if you could build such structures, would it be a practical thing to do?

Depends on what you are trying to do. While exploring what would actually be needed to terraform Mars and even giving it an atmosphere, just due to the amount of mass needed and distances involved, the energies needed are best described in units of total daily output of the sun. That is also where we'll need to get that energy, possibly by setting up very large collecting satellites to beam it to where it is needed around the solar system. It's pretty much the only way to get the energies needed to terraform a planet and even then we're speaking over thousands of years. Any such project would require such energy which would most likely be detectable by observing the light of the star in question.

Re:Circular reasoning

[djinn6]

I think you overestimate what it would take to make Mars habitable. A day's worth of solar output would easily vaporize Mars and turn it into a cloud of plasma (3.3x10^31 J heating up 6.4x10^23 kg of rock would raise the temperature by 60000 K).

But even if you're right, and aliens need planet-sized solar collectors, we've barely looked at 0.25% of the night sky with Kepler, and only 150,000 of stars in that area are close enough to be tracked by the telescope. Now the Milky Way has about 250 billion stars in it, so we've looked at 0.0001% of its stars. And that's just a single galaxy out of billions.

This is like seeing no squirrels on one pine tree and concluding that there are no squirrels on the entire continent.

Re:Circular reasoning

[datavirtue]

No gravity, no space travel. It is not practical. The human body will self destruct when exposed to zero-gravity conditions for relatively short periods of time. Just not something the dreamers want to focus on--real buzz kill. If you can generate gravity it still has to be controlled in relation to a spacecraft and the people in it--or on it. Earth is a magnificent space craft. It travels with an independent power source and generates its own life support--gravity is included at no extra charge. Be happy with what you got.

Re:Circular reasoning

[JoshuaZ]

Engineering is applied physics so that statement is something of a tautology.

No it isn't. The point is that this is something where things like nuclear propulsion should work; there's no fundamental physics barrier (unlike say with an FTL system or any other made-up technology).

That seems like circular reasoning. You are saying we don't have evidence of other civilizations because we don't have evidence of them trying to communicate with each other. But since such evidence would constitute proof of their existence your reasoning seems to circle back on itself unless I misunderstand where you are going with this argument.

I'm not sure what your point is here. The point that "If X exists, we should see Y. We don't see Y. So this reduces our credence in X" should be straightforward.

Why should we? We have no evidence or credible physics theory that such a structure is actually physically possible in real life. Heck, where would one get enough material to create such a structure? You could strip every planet in our solar system of every useful molecule and you still wouldn't have enough material to surround our star with a ring much less a sphere. Just because we can imagine something doesn't mean it's possible in the universe we actually live in.

We shouldn't necessarily see them. But if any sort of megastructures are doable,the incentive for an advanced civilization to try and make them will be high. And that goes up if leaving one's star system is tough. Moreover, the swarm variants of Dyson spheres and ring worlds don't require intrinsically advanced materials, and don't require that much material. Both Dyson swarms and Dyson bubbles don't require much more mass than a large asteroid https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_swarm.

Re:Circular reasoning

[JoshuaZ]

Gravity is one of the easiest things to simulate. Just need a large rotating section. We've known that since the 1930s.

Re:Circular reasoning

[Jamu]

If you're travelling it's even easier. You accelerate at 1G for the first half of the journey, turn the ship around, and decelerate at 1G for the second half.

Re:Circular reasoning

[ChrisMaple]

Volume of Earth: 260,000,000,000 cubic miles.
Length of Earth's orbit: 584,000,000 miles.
Dividing, that results in a cross sectional area of 445 square miles for a ring around the sun, using only the materials of planet Earth. Allowing a thickness of 528 feet, that gives a ring width of 4,450 miles.

Re:Circular reasoning

[darth.hunterix]

Surely you meant Uranus!

Re:Circular reasoning

[darth.hunterix]

Actually, that may be more interesting problem than you think: we know very little about how gravity actually works. What if it does to our bodies something MORE than providing 1G downward acceleration?

Who knows, maybe building a rotating space state station would teach us something new about gravity itself?

Re:Circular reasoning

[Junta]

Also, if you did build a Dyson Sphere, we probably wouldn't even notice the missing star. If we by some miracle noticed the anomalous gravity behavior, we would postulate a number of possible explanations that could not let us confirm a Dyson Sphere anyway.

Re:Circular reasoning

[JoshuaZ]

This seems extremely unlikely. If gravity has a substantial effect that is noticeable in any way that isn't just acceleration then General Relativity has to be wrong. Moreover, it would then in this hypothetical have to be somehow having an impact on people but not make any noticeable other difference to basic chemistry or physics of objects in space (where we can see they work pretty close to how we expect).

Re:Circular reasoning

[darth.hunterix]

Probably. But I'd like to see it verified by an experiment, and rotating spacecraft/spacestation is perfect for it.

Re: With morons like Trump "running things"

[LifesABeach]

One could observe that special agent Mueller is running #45

Extrapolating evidence

[sjbe]

Besides, the belief that we are alone, has a weird "we are special God-created creatures" stink about it.

Only to those already predisposed to confirmation bias thinking humans are somehow special. Objectively the only thing we can actually say is that we have not yet found any evidence of life anywhere but Earth. Any further conclusions are unjustified at this time. Thinking we are "special god creatures" is an unjustifiable stroking of one's own ego that is unsupported by any verifiable evidence.

As an atheist, I would assume life is everywhere, as there is nothing special about us. The only question is, how far away are they?

That is a reasonable theory but so far it is unsupported by evidence either for or against. I agree that it seems improbable that there isn't life elsewhere in the unimaginably vast universe but we also must acknowledge that the universe is under no obligation to conform to what we find logical.

Religion

[sjbe]

What's so terrifying about humanity being alone in the universe?

To answer that question look to what religious zealots do when they actually believe that hypothesis to be true. A lot of bad human behavior arises from us thinking we are more special than is justifiable.

Fermi Paradox is Garbage

[Jason Levine]

I've always hated the Fermi Paradox . "If there's intelligent life in the Universe, why haven't they come here?" There are a ton of possibilities that don't involve no other intelligent life in the Universe. Perhaps interstellar space travel isn't possible so all of the civilizations are stuck on their own planets. Perhaps they have expanded but simply haven't found Earth yet. (Space is huge, after all.) Perhaps they did find Earth and are purposefully not visiting the planet out of some kind of Prime Directive or "Nature Preserve" scenario. Perhaps they found Earth and visited it, but centuries/millennia ago. If alien spacecraft landed here during the stone age, they could have moved on and we'd never know they were here. There are so many more possibilities than "I don't see them right now so therefore they don't exist."

Re:Fermi Paradox is Garbage

[quenda]

I've always hated the Fermi Paradox .

Its easy to hate if you completely misunderstand something. First, lets agree that "paradox" is not the technically correct word.

It is not about physical visiting, and does not depend on the nature of the typical aliens. Earth could well be surrounded by numerous alien space probes, watching us from distant orbits, without us seeing them.

The idea is that the galaxy is so mind-numbingly big, and square that for stars in the observable universe, that even if only one in a billion stars gave rise to intelligent life and technology, the universe would be teeming with life. Even if 99% managed to stay silent, we would expect to see some.

  But we see nothing. No radio pollution, no communication signals, no rocket exhausts. So advanced technological societies must be incredibly rare. That may mean they do not last long. For us to observe another civilisation at the same level as us, it would have to be very close. Maybe the galaxy has had thousands or millions of such civilisations, but they just don't last long.

Consider, we already have the technology for large interstellar probes. It is just a bit expensive. https://en.wikipedia.org/wiki/...
Soon we should have the technology to detect such nuclear rockets a vast distance away.

Re:Fermi Paradox is Garbage

[Jason Levine]

Until recently, it was thought that planets were rare outside our solar system. We didn't have the ability to detect them and thus didn't "see" them. Then we developed the ability to detect super-Jupiter type planets and found a bunch. As our detection methods improved, we were able to see smaller and smaller planets. We still don't have the technology to see Earth sized worlds (though we're getting close). Something the size of a rocket would be invisible to us. In fact, recently we didn't even see an asteroid until it had entered our atmosphere. If a spaceship was parked outside of Pluto's orbit, we likely wouldn't be able to see it.

Communication signals/radio waves are easy to explain away: If your civilization is travelling between star systems, you'll need a better communication system than radio waves provide. The closest star to Earth is over 4 light years away. Imagine sending a ship there and needing to wait 8 years for every reply to your message to them.

There's also the question of whether we would know an alien signal if we saw it. First of all, we're only scanning a tiny portion of the sky. There could easily be signals in areas we're not looking at. Secondly, signals would be in an alien language and might be encoded. If you were given five data files and one might be in a language you've never seen before, encoded in a format you've never seen before, and compressed using a system you've never seen before, would you be able to tell it apart from the garbage files?

Finally, maybe the answer to the Fermi Paradox is that advanced civilizations are common, but space flight between stars is near-impossible. There could be hundreds or thousands of civilizations out there all wondering if they were alone in the Universe. Space is huge. There could easily be a civilization "close" to us (in space terms) that we'll never be able to reach.

Re: With morons like Trump "running things"

[LifesABeach]

Are you self medicating, again?

Re:With morons like Trump "running things"

[blackomegax]

You can't move faster than light, so transit between stars is largely prohibited at the resource level required to accelerate and/or hibernate your species. Even assuming immortal lifeforms, a transit that fast, hitting even one dust, goes boom. Then, OUR efforts to detect life are lacking and may never work. RF is the only good underlying physicial principle on which to communicate advanced information, but it dissipates after a few AU, even a focused beam would only go a few light years. You'd literally need the output power of a star to make a signal across the universe, and the reward vs effort is lacking when the sender is just as unsure as us they'd reach anyone.

Re:With morons like Trump "running things"

[Anonymous Coward]

Don't forget the network of quantum frequencies that plants and your brain tune into via DMT. We've already communicated with advanced alien lifeforms.

Re:With morons like Trump "running things"

[Immerman]

>The universe is still young by cosmological scales. Why do they assume that extraterrestrial life has to be zipping around the universe building Dyson spheres and shit? How do they know that there isn't life elsewhere that is less advanced than us, as advanced as us or more advanced but not starfaring?

Because our sun is pretty young by the standards of similarly metal-rich stars, and life appears to have started on this planet pretty much as soon as liquid water was able to exist on the surface, suggesting that the odds of life forming are very high. Unless we assume there was something very special about the inert rocks here (and it's generally considered poor science to assume we're in an unusual part of the universe), that in turn suggests that a similar process probably occurred around many other similarly metal-rich stars a billion of years before our planet existed. Even assuming life started on one of the other planets and migrated here via early-system impacts doesn't extend the timeline much (and if life migrated here from another star then it boosts the odds that the same thing happened to other stars as well)

And, given a billion-year head start, even one expansive space-faring species has had enough time to colonize the entire galaxy several times over by now. The fact that we see no evidence of that suggests that either we don't know how to look, or that in all that time not one species has arisen that is at all inclined to leave its home planet. Because once a species is firmly established in space, and thus has all the technology necessary for (slow) interstellar travel, and the proven inclination to expand beyond their world into artificial environments, it seems almost inevitable that some group will eventually head for another star - either for the uncontested riches waiting there, or to get away from a stellar civilization they find unpleasant, or even just out of curiosity.

Chemistry

[sjbe]

It is data, but it is wholly irrelevant to the question. We can detect planets, but can't tell if they support life or not from here.

That's not true actually. We can by looking at chemistry of exoplanets which we definitely can measure today. There are markers of life that can be seen from Earth. If we see certain organic molecules then we have strong evidence that life exists there. If we see life on an exoplanet that is likely how we will see it first.

Determining if we are looking at life that has formed what we would consider an industrialized society is a bit more challenging but still feasible. And if there is life then there is always the potential for "intelligent" life.

Re:Chemistry

[djinn6]

Where in that article you linked says we're able to measure the atmospheric contents of exoplanets? As far as I can tell they're looking at proto-planetary disks, which is quite a ways away from becoming planets.

Re:Chemistry

[sjbe]

Twenty seconds on google will find you all the articles you want on exoplanet atmospheric measurements.

Re:Chemistry

[djinn6]

You made the argument, so you need to provide links that support your argument. Is that hard to understand?

Evidence-based or conclusion-based

[raymorris]

> Besides, the belief that we are alone, has a weird "we are special God-created creatures" stink about it.

> As an atheist, I would assume life is everywhere, as there is nothing special about us.

I'm sure you didn't mean it this way, but that kinda has a certain "I intentionally choose confirmation bias over following the evidence" stink about it. I'm sure that's not what you mean, though.

We don't know about life anywhere else, and we can't even come close to agreeing what the word "God", even *means*, much less understand and prove everything about the concept. So the honest answer to most questions about these subjects is simply "we don't know". That is, once you go beyond certain descriptions of "God" as meaning basically physics and concepts like "truth".

Given that we don't know, we only get hints throughout my our lifetime, we can choose between two ways to think about it, conclusion-based (faith-based?) or evidence-based.

Suppose I'm introduced to a person I don't know, names Rob Smith. I'm asked to guess whether the Rob Smith is a) a career burglar or b) founded and runs a homeless shelter and soup kitchen. I guess, somewhat arbitrarily, that Rob is a career burglar. I then stumble upon the fact that someone named Rob Smith, perhaps the same person, gives 80% of his income to charity.

I can have either of two reactions to the news that Rob Smith is very charitable. I can either adjust my initial guess, saying "perhaps this Rob Smith is a actually a good guy. What little evidence I have is starting to point that direction." Alternatively, I can say "nope, it can't be the same Rob Smith. I already guessed that this guy is a crook, so I won't believe the evidence."

I can either let my foregone conclusion (guess) affect my view of the evidence, or I can let the evidence affect my estimate of the unknown variable. Although most would argue that logically our conclusions should be based on the evidence, for whatever reason we humans have a strong urge do the opposite - letting our previous guess decide how we view the evidence. We're really, really bad about that in politics. I reject all evidence that Person A is doing anything good, because I voted against them. That makes us tend to say things like:

I don't believe any evidence of X, because a long time I guess that Y was false, and if Y actually is true, that would be evidence that Y could be true - that my guess might have been wrong. I reject the evidence because it doesn't support my guess.

There a million different beliefs about God, "anything that anyone calls God therefore does not exist", based on many different sets of reasoning, some evidence-based, some experience-based, and some more extreme conclusion-based, what some would call faith-based (for an extreme definition of "faith"). The extreme faith-based schools of thought, basically cults, say:

I believe X about God, so I reject / ignore all evidence to the contrary.

This cultist way of thinking isn't limited to David Koresh followers. There is a cult sect of atheism that says "all of the million or so descriptions of something someone calls 'God' must be dead wrong, so therefore we reject all evidence and reasoning which suggests anything more powerful than a human has ever existed". That's an act of extreme fact, cultish faith.

There are, of course, other varieties of "atheism". Perhaps the most common is "my mom believed X, Y, Z about God. I think my mom was mistaken about at least one of those. I don't believe in the same idea of God that my mom did. As for the other thousands of ideas about different things people call God, I don't even know what all the different beliefs are, so I certainly can't know which ones are right. I'm just pretty sure that my mom didn't have the God thing all figured out. So if my mom's idea of God wasn't quite right, that leaves me with no understanding of God that I can believe."

Re:With morons like Trump "running things"

[Immerman]

>which will always be the most suitable place for human habitation

Lets not make any assumptions - after a few million years of terraforming, Mars and Venus might be every bit as suitable - especially after being relocated to more hospitable orbits.

Re:With morons like Trump "running things"

[Oswald McWeany]

>which will always be the most suitable place for human habitation

Lets not make any assumptions - after a few million years of terraforming, Mars and Venus might be every bit as suitable - especially after being relocated to more hospitable orbits.

True- although even then they wouldn't be MORE suitable, only EQUALLY suitable. If we can terraform Mars and Venus we would also certainly have the technology to restore Earth to it's former glory pre any pollution and man made climate change.

Re:All ours!

[Anonymous Coward]

Except Europa. Attempt no landings there.

How do we know?

[Cro Magnon]

Our ability to detect life out there is limited. We're lucky to see anything smaller than Uranus at interstellar distances.

Re: With morons like Trump "running things"

[Anonymous Coward]

Or, maybe even huge, spacefaring civilizations that have colonized the galaxy are hard to see. Maybe weâ(TM)re already inside one and weâ(TM)re leaving on a reserve of some kind. Off limits to everyone except anthropologists. Or maybe only half the galaxy is populated by star daring civilizations, and we arenâ(TM)t in that half.

Whatâ(TM)s interesting about the question is that it is one that can only be asked by people who are not in contact with a spacefaring alien civilization. We only ask, where is everyone, because we donâ(TM)t know. So maybe we are in special circumstances, but that doesnâ(TM)t mean that weâ(TM)re alone.

What this kind of argument always makes me think is that people who canâ(TM)t bear the thought of a kitten dying should never get good at math. Domestic Cats produce large litters and are fertile after a few months. Domestic cats have been around for at least four thousand years. For some reason, however, the earth is not covered in a thousand mile thick layer of cats. Of course, a thousand mile thick layer of cats is obviously ridiculous and unsustainable. So is being knee deep in cats. There is an equilibrium level of cats that is sustainable, however. Exactly what that level is depends on a lot of factors, some of them quite unpleasant for kitten-lovers. The point is, I donâ(TM)t see a cat right now. I could search the entire building I am in and I would not find a single cat. And if I could only remember back a few hours, and/or if my eyesight, hearing, etc. had dramatically improved since this morning I would have to conclude that cats are probably not real. Even though I have several cats in my home, and even if one had been sitting on my lap, purring this morning. And that is the way it goes with the search for intelligent life. Our civilization has not been looking for long (and, frankly, not very hard at all really) for life elsewhere in the universe and even if weâ(TM)d encoutered it directly, our historical records of anything like that from more than say 500 years ago would probably be useless (consider that the Romans were quite literate and kept lots of records, and we are still not really sure if, for example, Caligula actually existed).

Basically, until we get out there ourselves, we canâ(TM)t really conclude anything. Right now weâ(TM)re massaging the data we have (which is mostly an absence of data) into something that itâ(TM)s not. Sure, we know that there isnâ(TM)t an alien civilization slapping Dyson spheres around every nearby star in recent history because we would see the stars going out. On the other hand, if thousands of 100 km long starships weâ(TM)re traveling back and forth every day between every other star in the galaxy, they would be completely invisible to us. Ditto if itâ(TM)s much lighter traffic and much smaller ships. So, sure, we can rule out some levels of technology (at least nearby and recently), but we really havenâ(TM)t scratched the surface.

Seriously Interested in the Paradox and I Read TFA

[careysub]

I read a lot of papers about the Fermi Paradox and most of them are worthless in addressing it - they typically take the form that "all civilizations will (or won't) do X and so the problem is solved" and in the "will" case is based on something that the only civilization known has not yet done. The assumption of some special behavior does nothing to address the paradox since it is universal in nature - it has to apply to all cases given that we see no evidence of civilizations at all.

This is one of the best papers I have seen, since it directly addresses the paradox, addresses the fundamental problem with analyzing it (uncertainty of the Drake parameters) and does not appeal to some special case solution. Also, given the valid formulation (many random variables with broad logarithmic distributions) their result isn't very sensitive to whether there are defects in the distribution modeling of any particular parameter.

But I do have a few of comments about their treatment, and about the subject as a whole.

First about the subject as a whole

Point one. Tthe probability of civilization in the Observable Universe is not relevant at all to the Fermi Paradox. Intelligent signals from distant galaxies would have to be broadcast to the entire Universe to have any useful chance of us being in the way of the signal to intercept it, which means the signal would have to have a power larger than actual stars. The Hubble telescope could not detect an optical signal at all as bright as the Sun at a billion light years, similar limits exist for radiotelescopes. Also, no intelligent civilization is going to be arriving here from distant galaxy groups. Even fusion propulsion will limit probes (that slow down) to about 5% c. The Universe has only been able to support long-term life for about the last 8 billion years (early Universe was too violent, heavy elements had to accumulate) so no probe from a civilization farther away than 400 million light years could even reach us. Thus even the most extreme volume relevant to the paradox is only something like 1/100,000 of the volume of the Universe, and I would argue really only the two large galaxies in the Local Group is relevant (the next closest group is 10 million light years away).

Point two. Arguments that we have "only one data point" when discussing life on Earth abuses the term "data point" horribly. We have only one system to observe, true, but it covers vast numbers of natural experiments across a billions of years, so it provides a great deal of data about the properties of living systems. In fact rare events in that history tell us a lot about the likelihood of those events.

Now about the paper. I have some objections to their modeling of two of their parameters, but the objections go in opposite directions and thus tend to cancel out to some extent.

Their distribution modeling of the origin of life is astounding. Due to our poor understanding of the processes of biogenesis (which they attempt to model) they assign a range of greater than 200 orders of magnitude (there are no more than 10^82 atoms in the Observable Universe). Given that life on Earth developed almost as soon as conditions permitted it (~100 million years after the end of sterilizing bombardments) actual evidence indicates that with suitable conditions is happens rapidly, and thus with high probability over a planet. It would be appropriate to consider the probability of a clone of Earth, but the approach they take to try to model biogenesis is not credible. In this case we do have actual evidence supporting a conclusion that it is likely with the right conditions. In other words, they are relying not so much on real uncertainties, but on poor arguments about uncertainty.

But by the same sort of consideration their uncertainty range for the probability of technological ("intelligent") life is implausibly large. They assign a log-uniform from 0.001 to 1 (based on "the literature", no discussion is offered), thus asserting that given life the likelih

Re:With morons like Trump "running things"

[lgw]

The rational position for star travel for "today's humans" is agnostic. We don't know a way to travel fast, but we're a long way from ruling out such mechanisms. However, it's worth keeping in mind that humans greatly extending our lifespan is a different approach to interstellar travel, and one that may be lower tech than other approaches.

To the bigger question of the Fermi Paradox, human-specific limitations aren't very satisfying as an answer.

We won't see anyone else....

[bev_tech_rob]

until we invent Warp Drive. Then the Vulcans will show up.

Time scales are messing with people's views

[dlingman]

Folks. The universe is billions of years old. We've been transmitting radio since the 1890's That's under 125 years ago. And even then was insanely low powered. That's not far. If you add a bit, and look at what's within 100 light years of us, there are around 512 G type stars within that 100 light year range.

That 100 years is a tiny amount of the time that we've had civilization, and a minute amount of time that we've had life on our planet

512 is not a lot. And they'd need to be looking directly at us in the past 100 years to even have a chance of noticing us. What are the odds that they aren't at that level of tech yet, or have gone past radio waves to something else that we'd not be able to detect yet?

They may be out there, or not, but the odds of them screaming at us in the last 100 years is pretty low. The further out you get, the harder it is to even pick up a signal, and they've got no reason to suspect that they needed to broadcast at us, since our signals haven't gotten there yet...

Re:Time scales are messing with people's views

[quenda]

That's under 125 years ago.

You've totally missed the point. It is not about them seeing us, but us seeing them. Just one of countless them.
If all technological civilisations died out within a few hundred years and did not spread, that would be an answer.

Doesn't EVERY study suggest that?

[Cajun Hell]

"We May Be All Alone In the Known Universe" is what has been at least suggested by 100.0% of our observations, since nobody-else is what we keep seeing, over and over again.

If you ever looked up with a telescope, our aloneness was suggested to you too, whether you noticed it or not. ;-)

Re:With morons like Trump "running things"

[sycodon]

"starfaring" may be impossible in practice.

Which pretty much destroys the entire premise this study.

What the fuck with the logic that faster than light travel is impossible and since no one can do it and subsequently hasn't' visited us, then there must not be anyone?

The idea that we are the only ones in billion and billions of stars and planets is preposterous and pretty fucking arrogant.

Have More Children

[pubwvj]

Elon is right and this is precisely why I argue that people should have more children, and read to them. (The start of the path of education, encouraging minds.)

We need a LOT more people.
It takes a LOT of people to support the people at the edge who move us onward and outward.

Don't bother arguing that the planet can't handle more people. That is merely a consumption problem. Reduce your footprint. Based on the resources my family consumes the world can handle 50,000,000,000 (50 Billion) people sustainably leaving 25% of the land area, all of the polar areas and almost all of the oceans alone. If you can't do it you're doing it wrong.

And if you don't want to have kids then please don't. I wasn't really talking to you specifically although you can support your sibs, friends and society in the endeavor.

Meanwhile, in another story...

[whitroth]

NASA has a group wondering if we'd recognize alien life if we see it.

The Fermi Paradox... I have a really simple answer. the requirements for us to observe them:
1. they need to be located within range that we can detect.
2. they need to be a techological species, as we define "technology".
3. their tech needs to be within +/1 150 years of our current tech.

Otherwise, they're either too primitive to send aignals that we can observe with current tech, or too advanced. Quick: how many Victorians could have read this post, over the Net?

I'll also point out that we mostly stopped broadcasting 100,000 watt radio stations.

Unlikely spot

[Tablizer]

TFA: and yet the probability that we are alone in the galaxy is 30%

Where does this come from. And civilizations can spread across galaxies in "reasonable" time-frames.

One possible clue is that we are on a galactic island, relatively speaking. The Copernican principle would statistically put us in a denser cluster of galaxies. Our galactic neighborhood is sparse. Our isolation may suggest some kind of filter is active. There may be a reason we are in the boondocks such that we are alive pondering why we are in the boondocks because being in the boondocks either helped bring us about or protected us from a danger.

For example, perhaps beings in most dense galactic clusters have been dominated by a single force, self-annihilated by some run-away inevitable technology, or there is some kind of "dark radiation" we don't know about that's too high in big clusters.

Re:Important detail missing

[Green Mountain Bot]

Fermi basically said that the window of life (from birth to the "great filter" event was too short to occur (very often) simultaneously with other civilizations. (In other words, life exists elsewhere, just not at the same TIME as any other civilization, because they kil themselves off so quickly.

Fermi didn't say that. Robin Hanson did. The Great Filter is one of many postulated explanations of Fermi's paradox.

My personal feeling is that the correct explanation is a combination of the Earth not being old enough (or being the first) and space being too big. I think third generation stars are a necessary prerequisite to advanced life, which reduces the amount of time available for that life to emerge by two thirds. Add in the necessary time for planets of third generation stars to coalesce and cool down enough for life to form, and then the amount of time necessary for primitive life to evolve into advanced life, and the horizon within which we would be able to detect and interact with such life becomes quite small.

flawed premise of study and Fermi paradox

[presidenteloco]

The study sets out to explain "the apparently lifeless universe we in fact observe".

But that is bollocks.
We have not observed far enough away with enough precision to determine lifelessness, and given the low resolution (spatial and spectral) of our observations, absence of evidence is not evidence of absence.

We are only now starting to catalog exoplanets, and have not observed any of them in spectrographic detail.

In terms of time, any civilization looking for us would have to be within 150 lightyears of us (a tiny distance on "observable universe" scales, to have detected our radio emanations phase. And that phase of unencrypted (i.e. non-random) and/or analog radio communications is quickly coming to an end, as we move to fibre-optics and encrypted digital which seems like noise if you don't have the decryption key.

So we have not done anywhere near enough observation to even establish an empirical probability of absence of life in the near quadrant of our own galaxy, never mind the observable universe. Preposterous assumption underlying this study.

Absolute zero. Kelvin

[raymorris]

I suspect GP was thinking of 0 Kelvin, absolute zero. Saying Celsius may have been a mistake.

Re:With morons like Trump "running things"

[Kjella]

Why not both? It certainly isn't "pointless" to want to expand the human condition and strive to create a backup for earth and all life as we know it. (...) starting with Mars.

It's easy to confuse presence with progress though. It's been 45 years since a man walked on the moon but science and technology has not been standing still, would we have been better off if the US had kept pouring billions and billions of dollars into Saturn Vs instead? Maybe, but maybe those resources were also well spent here on Earth. I mean a working backup that could exist fully independent of Earth is probably centuries away and it's not immediately obvious that time will solve anything. I mean you've had McMurdo in Antarctica for 60 years but it's not like they make it more habitable, a Mars outpost would be the same unless you found some kind of terraforming project they could do. Of course maybe a research outpost would be nice too, but it's not like one automatically leads to the other.

Re: With morons like Trump "running things"

[LostMyBeaver]

As we automate, communism becomes almost a requirement. Capitalism will not survive our current path of evolution. Already America, the beacon of capitalism is forced to eliminate massive numbers of people from the work force by maintaining a huge military, an enormous TSA, gigantic bureaucracies, a massive prison system, etc... if the US government canâ€(TM)t build a capitalistic society without massive socialist programs, what about China, India and other countries?

We will have to embrace communism and live something of the Wall-E life of people generally producing and contributing nothing before we adapt the system to let people like me work because we enjoy it and let everyone else live a perpetual vacation.

Next time you visit a Walmart or similar store, count the massive amount of crap that exists for no other reason the producing eventual toxic landfill because we need to make sure people produce crap so other people can sell crap so other people will buy crap simply because we need to support capitalism.

I bought a BMW i3 recently, 2 years ago I think. I expect it to my last car. It has almost no corrosible parts and once self driving ride sharing happens, Iâ€(TM)ll leave it parked most of the year. Even now, lots of people in cities are using car sharing instead of owning vehicles. This means jobs for mechanics, parking attendants, car assembly line workers, etc... will disappear. Once an app for farm vehicle sharing comes around, there will be a similar trend in rural areas.

Information sciences will destroy capitalism.

So, once that happens, money will have far less value. And to be fair, China or some other country willing to embrace communist ethics sooner will invest the time and materials to send us to the moon, Mars and beyond. The U.S. will fail because there is an inherent belief that competition is better than cooperation in America.

Iâ€(TM)ve been talking with my kids about the value of micro houses instead of contemporary home ownership. They agree that the only reason you really need so much space is because of all the useless crap we collect. They donâ€(TM)t need book shelves as they have ebooks and libraries. They donâ€(TM)t need desks as they have laptops. They donâ€(TM)t need a 75†TV because the room is small enough to enjoy a 40â€. I believe their generation will favor living in structures similar to â€oethe stacks†from Ready Player One. Theyâ€(TM)ll need less money, theyâ€(TM)ll buy less crap, theyâ€(TM)ll use less energy, theyâ€(TM)ll generate less trash. Theyâ€(TM)ll depend on communal resources as opposed to personally owned. If they use clothing rental instead of ownership, they can avoid having so much crap theyâ€(TM)ll never wear.

No, I think cost will not be an issue. Time will.

Re:With morons like Trump "running things"

[TheFakeTimCook]

>which will always be the most suitable place for human habitation

Lets not make any assumptions - after a few million years of terraforming, Mars and Venus might be every bit as suitable - especially after being relocated to more hospitable orbits.

I worry about that last bit.

Planetary Systems are like fairly intradependent, gravity-wise. If we start messing with the orbits of a systems' planets, we might start a cascade-effect with the star and/or other planets in the system, that very well might start and/or accentuate "wobble" that we may or may not be able to stop/control.

Full disclosure: IANAA (I am not an Astrophysicist). But this does seem a fairly reasonable "worry".

The Fermi Paradox isn't a paradox...

[Timothy2.0]

There's nothing paradoxical about the Fermi Paradox in the first place, so hinging a study on it is already wrought with problems.
The seeming lack of evidence for technologically advanced species out in space comes down to two problems: the speed of light and the inverse square law.

Think of humans being detected: we've had radio for just over a century, making any detectable radio transmissions detectable to a maximum of just over 100 light years (due to the speed of light). This assumes that such transmissions are sufficiently powerful to be detected above the background radio noise of the galaxy, and the further from Earth we go, the weaker those transmissions will be (due to the inverse square law).

As such, we need to be within detectable range of an advanced race, or they have to be within detectable range of us. As the distances to be covered are massive, the two above laws make it unlikely, without a massive revamping of our understanding of the nature of the universe, that any advanced races will ever detect each other.

We could be 500 light years from an advanced civilization and have absolutely no idea.

Re:The Fermi Paradox isn't a paradox...

[HiThere]

More to the point, if we were 100 light years from an advanced civilization that was really interested in communication with aliens, they'd have just started on their way...or maybe wouldn't have started yet.

But robot probes seem more likely to me. Not that we'd know about *them*, either.

Moving planets

[Tenebrousedge]

There's not really any conceivable way to do any such thing, nor any purpose which would be best served by it, and other side effects of that much energy expenditure would be of far more immediate concern. If my math is right, the energy required to move Mars to Earth orbit would be about 20x its gravitational binding energy. You probably don't want to just give it a big whack, and the list of things that would probably be easier would probably include disassembling the planet and moving it to a new orbit piecemeal.

Re:Moving planets

[Oswald McWeany]

He mentioned a few million years. If we're around in a few million years I can't even imagine what could be possible.

Re:Moving planets

[suutar]

Larry Niven came up with the idea of sticking a fusion drive on/in Neptune a while back. Could use that to nudge the orbits of venus and mars without breaking it up, if you're careful to ensure that closest approach doesn't generate too big a tide.

Still needs Explaining

[Roger W Moore]

The universe is only 'old' from our point of view. A much colder planet where its life's metabolism and reproductive rates are low, might evolve much slower than life on Earth.

Assuming that even is possible you then have to explain why we are the only planet in the galaxy and possibly the known universe where evolution occurs at a much, much faster rate. The simplest explanations for the Fermi-paradox are that interstellar travel is extraordinarily hard and takes lots of resources and lots of time or that the evolution of intelligent life is exceptionally rare - after all, it took 3 billion years to evolve multi-cellular life on Earth. Our current understanding of fundamental physics suggests that the former is probably true and we have no reliable data to estimate the other. However, if interstellar travel is exceptionally hard then, even if intelligent life does evolve it might not make it that far from its homeworld so it might not need to be that rare for us to never see it.

Perhaps we're just unusually stupid

[Locke2005]

We're the only intelligent species stupid enough to broadcast "Here I am, come kill me!" to every xenophobe in the universe.

It's a knowledge problem

[Roger W Moore]

I think it's not so absurd to think that it could have happened only a very few times in all the universe.

We have literally no idea. After that initial spark of life on Earth it took 3 billion years before the first multi-cellular lifeforms evolved. So while life may be highly probable multi-cellular life might be exceptionally rare but then again perhaps we are an outlier. With a sample of one planet, the only thing we can really say is that the probability of life evolving is not zero but whether that probability is 10^-40 or 10^-1 we have no way of knowing yet the difference is a galaxy teeming with life vs. just us in the entire observable universe.

uncanny valley of Saganometry

[epine]

Now given the gigantic (known) number of galaxies containing a gigantic number of stars, even if that life probability is low, that would be quite a stretch to conclude life exists only on Earth.

At what magnitude does any finite number become probable (more probable than 1 or 2)?

Has your argument eliminated 10, 100, 1000 with equal weight? If not, estimate—if you dare—your coefficient of enhanced probability for these (very slightly) larger integers.

———

Or, how about we get first things first?

We don't even know if the process of life formation is fat-tailed or thin-tailed. (Or do you somehow know this, and you just haven't shared this yet?)

Back-of-the-envelope works pretty good for thin-tailed distributions.

Back-of-the-envelope barely ever works out right for fat-tailed distributions (and this particular envelope is made from the precious fibres of papyrus durphdurphi to begin with, which does not bode well).

———

Here's another N=1 anecdote. So far life on earth—over the past 4 billion years—has observed precisely one celestial phenomena in both the gravitation and electromagnet spectra at the "same" time (those are not scare quotes, they're the lesser-used Michelson–Morley conundrum quotes).

Now isn't it amazing, given the observable size of the universe, that any measurement perched at the top of the charismatic, existential food chain could pass through the value one, even for a few short years?

The way I was educated in the mathematics classroom, counting sequences that rarely pass from 0 to 1, tend not to achieve 2 with great frequency. But actually, in this matter, I disagree with my education. Lines this bright tend to be arbitrary in the first place, and actually represent an abstract limit on a far messier process in the real world. (What's the slope at human conception? I doubt we could pinpoint the precise moment of conception with resolution better than 1 ps, so I rate limit God at a trillion souls/second per fertile woman. Concerning the second derivative, this immediately devolves into two challenging problems, perhaps of equal, or lesser (or greater) difficulty: (1) determining the precise moment of fertility—lessor?—and (2) the precise moment of woman—greater?—though perhaps this second determination was a singular N=1 event in all of cosmic history, for a sufficiently sharp (and local) definition of "human" (again these are not scare quotes, they are the lesser used Ramakrishna–Vivekananda conundrum quotes, who, more or less contemporaneously with M–M, were busy observing a second corner of the "same" elephant).

———

Well, suppose we even knew how life originated here. Suppose even that's there a biochemically preordained sequence of complexification that leads inexorably to modern humans, modulo epicanthic folds and minutia of that nature. Let's further suppose that the primordial soup isn't faster than God, so it can't spit out the first fully formed cell wall in less than `1 ps. Then there would necessarily be some kind of tau, a time constant, wherein chance and probability are given a discrete interlude do their thing.

Would this ladder have ten rungs? Or would this ladder, observed more closely, have one hundred rungs? Or observed yet more closely, one million rungs? Each with their own tau, along the inexorable monorail of complexification?

Bear in mind, that this monorail could well extend beyond human life in its present form. And presumably, if you sampled far enough down the line, you'd eventually find a stage of pan-galactic convergent evolution which only a single life form in the entire observable universe had yet attained, sapiens xenohari.

———

Big data to the rescue! [auspicious horn tootle]

Suppose we sample every suitable rock in the observable universe in the enthalpic, e

First Ones

[jwhyche]

I always liked to think that we might be alone and we are the First Ones. First Ones as in Babylon 5 first ones. The universe is still young, 14B years, and has a lifespan predicted to be in the trillions of years. Some one has to be first, why not us?

Re:First Ones

[philmarcracken]

The first or... just another in the line of consciousness that evolves sporadically only to accidentally kill itself soon after.

Re:With morons like Trump "running things"

[Areyoukiddingme]

A generation ship is perhaps a theoretical exception, but it will take a big chunk of Earth's resources and is unlikely to reach its destination given all the things that could go wrong with the equipment or crew on the way which could doom the ship.

It's fairly obvious that no one would be building a generation ship until they're exploiting a big chunk of the solar system's resources, making the chunk of Earth's resources comparatively small. And that also solves the equipment and crew problems by default. Any civilization successfully exploiting a solar system's resources has encountered and solved those problems pretty much by definition. If they hadn't, they wouldn't be successful.

A civilization spanning a solar system can build a generation ship. A planet-bound civilization can not. There are no shortcuts. If the Earth's space programs have taught us anything, they've taught us that you don't understand it until you build it, it fails catastrophically, and you build it again differently. That's how architecture happened too.

I'll go so far as to say that a civilization spanning a solar system will inevitably build a generation ship (assuming no clever physics happen). It's The Next Thing. A civilization successfully exploiting the resources of its solar system is gigantic in terms of sheer numbers and fantastically wealthy compared to a planet-bound civilization. A generation ship becomes the next Antarctic Outpost project. Doesn't really make sense (ignoring the military reasons for the seismometers in Antarctica), but it's something to do. The story of human history can frequently be summed up as: doesn't really make sense, but it's something to do.

Re: With morons like Trump "running things"

[Immerman]

That is rather the point - we're not knee-deep in cats because there are equilibrium forces on cats (namely starvation and predators). The Fermi paradox essentially asks, "What are those equilibrium forces on galactic civilizations?" An embargo might be possible - but it would require 100% compliance of every single individual in the galaxy, which seems unlikely.

Basically it's not trying to reveal some great truth - it's prompting the asking of questions, which might eventually do so.

As for maybe half the galaxy already being part of a galactic civilization, that doesn't really answer anything - why would such a civilization stop expanding? The sort of head start they could have would make crossing the entire galaxy look like crossing the street.

And heck - the answer may even be that we've grossly overestimated the probability of intelligent life arising in the first place, and really are the first potentially space faring species to arise in this galaxy. Even that answer would be immensely informative, as it leads us to more critically analyze our assumptions of the preconditions.

Re:With morons like Trump "running things"

[Immerman]

Maybe. Cleaning up radioactive and nanotech pollution might prove considerably more difficult than we'd like though, to say nothing of engineered pathogens. And it may turn out that humans actually take quite well to 40% gravity. Not to mention we may find there are serious problems caused by fracking, mining, and other practices that damage geologic structures that are potentially irreparable on less-than-geologic timescales.

Re:With morons like Trump "running things"

[Immerman]

Sure, though it's unlikely that anything we do with a few tiny pebbles is going to make much difference to the sun. The sun is 99.9% of the mass of the solar system, and Jupiter alone is around is around 70% of the remaining mass. All the rocky planets combined are barely even a rounding error in comparison.

You do get orbital resonance between planets though that certainly will destabilize things over a sufficiently long time period - it's already doing so, the planets have been migrating around since long before the Earth's surface solidified. However, if you're capable of moving planets around, you're capable of correcting such resonance drift. You can even make that resonance work for you by intentionally putting things into some of the more stable resonances to begin with, so that the system will tend to self-correct.

And of course there's Lagrangian-inspired arrangements if you actually wanted the planets to share the same orbit - though that might take a full six equal-mass planets to actually be stable, and I'm not certain even that would work.

Re:My Take on Homo Sap

[shoor]

Imagine the first amphibian to walk on land. It probably wasn't very good at walking. Imagine the first bird to fly. It probably wasn't a very good flyer.

Homo Sap is the first animal to achieve what I will very loosely call 'civilization'. How good do you suppose Homo Sap is at it?

The descendants of those first amphibians got better at walking, and the descendants of those first flying birds got better at flying. (Most of them anyway, not the ostriches and emus.) With homo sap things may be a bit more complicated.

Personally I think part of the ability to be civilized is being able to follow leaders. Presumably you should pick good leaders to follow. That's at least one of the places that could stand a lot of improvement as far as human nature is concerned.

Re:With morons like Trump "running things"

[Tough Love]

we deserve to go extinct instead.

It was my first thought. Then I thought, why let that moron dominate this thread? Then I thought "alone in the universe with Trump".

Re:With morons like Trump "running things"

[ahodgson]

I dunno. Civilizations change, too, over fairly short periods of time. Romans conquered half the known world, once. And 200 years later they were begging for bread while watching lions eat people, happy to let Germans do their fighting for them.

Our own civilization went into space and built a lot of cool things. But now we read Facebook and sell ads to each other, and protest at the slightest hint that someone might actually build something.

So there's no guarantee that a civilization that goes into space will continue to expand.

Re:With morons like Trump "running things"

[Immerman]

Our civilization has NOT gone to space - we've sent a few robots, and a handful of tourists and researchers to the nearest edge (we've never sent even a single human beyond Earth orbit), but nothing remotely resembling civilization, or even a serious outpost. I assume we will do so eventually, though not necessarily before our current civilization collapses and rebuilds again. (Also, don't make the mistake of projecting the decadence of the U.S.'s decaying culture to the rest of the world - China, India, etc. are quite busy actually building things)

Once you have actual civilization in space (and not just outposts dependent on the home planet) then you have selective pressure at work - pretty much anyone who goes to space is likely to do so because in their vision the promise of space exceeds that of remaining on Earth - that's going to be a fundamental "truth" in spacer culture. And if there's any genetic component at all that biases the colonists vision in that direction, it will be concentrated and amplified in their descendants.

Spacefaring... BS, I don't buy it

[omfglearntoplay]

Businessheads might want you to give them money to travel in orbit like space junk for a few hours, but I've been on long flights across oceans and they unequivocally suck.

How the hell are we ever going to get another planet in better shape than what we have here now if we keep pretending it doesn't matter because we are moving on in a decade or so (more like another billion years)? Take care of this planet, seriously. I guess it's going to take capitalism or some crazy kingtype somewhere to change the human culture in order to keep the planet Earth livable.

Re:Spacefaring... BS, I don't buy it

[walllaby]

I guess it's going to take capitalism or some crazy kingtype somewhere to change the human culture in order to keep the planet Earth livable.

What do you think brought us to this point?

Why the silence

[glider524]

Given the silence of the galaxy and the universe in general, and examining outward and our own history, it seems safe to say there are some boundary conditions: 1) Our galaxy has not been mass colonized by any single or multiple set of alien civilizations (barring a Zoo Hypothesis). 2) If alien civilizations do commonly exist, none of them have put forth a fully-engaged attempt to broadcast their existence. 3) Life is delicate but arises quickly and perseveres when environmental conditions allow for it. 4) Evolution tends to become static unless periodically disrupted.

With what we know of chemistry, it is difficult to conceive of any type of life not based on liquid water. No other substance has the unique properties it does. Planets with continuously liquid water are likely relatively rare. It takes a 2nd or 3rd generation metal-rich star to allow for heavier elements to exist. In particular, any planet without a spinning metallic inner core will not have a magnetic shield in place to protect its water from being sandblasted away by solar wind over billions of years (as happened with Mars). It’s one thing to have rocky planet covered with liquid water, but protecting the water for billions of years from slow solar radiation destruction is likely rarer still.

The first 3.5 billion years, all life on Earth was single-celled. Only in the last 500 million years did life evolve in to a complex multicellular variety. Given that the majority of the history of life on Earth was single-celled, this likely means that where it does appear, life probably some portion of the time never evolves past the single celled stage. What evolution requires to become multi-cellular are mutagenic boosts such as ultraviolet radiation. The ozone layer on Earth allows just enough of solar radiation through to promote genetic mutations without being deadly. Many planets with rare, ultra-long-term stable liquid water may lack this evolution jump-starter.

It took 500 million years from the appearance of multicellular life, with several long-term stable periods punctuated by violent upheavals and resets (e.g. dinosaur asteroids extinctions), for the appearance of intelligent life to finally appear. Without major planetary upheavals, possibly multicellular life tends to fall in to static stable long-term dead-ends. Those rare, stable, liquid-water-filled worlds with sufficient mutagens to encourage the development of multicellular life sometimes never get the periodic kick in the pants to reset the course of evolutionary paths out of dead-ends.

Possibly many stable, watery planets with sufficient radiation and punctuated evolutionary disruptions never develop intelligent life. It took 500 million years for it to arise on ours, which is anecdotal evidence that some significant portion of the time, it never arises. Out of the few planets that do evolve intelligent life, a couple questions arise then as to their likely destiny. It seems universally inevitable that intelligent species eventually have to deal with advances in biological and artificial intelligence technology.

How long will it be now before our species obtains relatively full technological control over our genetic code? There will be natural temptations and drives to use the technology to eliminate disease, choose traits, then maybe even super-enhance the physical and mental capabilities of our offspring. Fast forward a thousand years of having this technology of gene splicing and tinkering, will our designed descendants eventually not much resemble the original naturally-evolved species? It’s hard to imagine what stable end-state this technology might result in over the long term. Possibly we could eventually design and create immortal, super-strong, super-intelligent beings which we in our current form would be completely inferior to. Along with those changes, maybe we might seek to eliminate the traditional instinctual drives that pushed us to survive, spread, and procreate. As a matter of societal stab

Space travel is simply too hard to do

[Eravnrekaree]

Its probably because interstellar travel given the distances is involved is nearly impossible to do, they decided it wasnt worth the effort and environmental damage it would cause their own planet. That is interstellar travel attempts could be a threat to the habitility of our own planet unless we use resources from other planets like pick up Hydrogen and other gases from Jupiter.

Plus you have all of the radiation in space and the fact that travelling through space would pretty much suck, being stuck in some nasty little capsule. This is really the best explanation for the paradox.

The universe is probably teaming with life but no one wants to go to the trouble to try interstellar travel and its just way too hard to do.

Re:Space travel is simply too hard to do

[quenda]

Its probably because interstellar travel given the distances is involved is nearly impossible to do

It is quite possible if you don't mind taking decades to nearby stars.

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

Such probes could report from most of the galaxy within a million years.

This paper belongs in theology not science

[AnthonywC]

And once again some people make the retarded assumption that somehow we are special. From discovery of evolution to special relativity, we found that our notion of 'special' status in the universe is extremely misguided. It is sad and pathetic to keep seeing this from people, maybe even scientists no less.

Re:With morons like Trump "running things"

[TheFakeTimCook]

As I said: IANAA ;-)

Thanks for the edjumication!

Re:With morons like Trump "running things"

[Tough Love]

How do they know that there isn't life elsewhere that is less advanced than us, as advanced as us or more advanced but not starfaring?

Nondetection of signal-bearing radio waves tells us that there is no civilization as advanced as ours within ten or twenty light years of us, which includes a hundred or so star systems, some with planets. So we know that the local universe is not teaming with intelligent life. Other possibilities aren't ruled out.

We will certainly travel beyond our own solar system at some point, that is, if Trump does not manage to sterilize the planet first. Because of relativity, we will not leave in our current fragile, short lived forms. Whatever we evolve into, we will need lifespans of at least tens of thousands of years, and more realistically, millions, in order to appreciate the wonders of worlds beyond.

Re:With morons like Trump "running things"

[Tough Love]

Should we move to Mars? It will be very expensive and mostly pointless.

Some would say the same about moving to Iceland.

Re:With morons like Trump "running things"

[neoRUR]

Yes I agree, arrogant. We have always thought that we were the center of the universe until proven wrong, so we will think we are the only ones in this massive universe until proven wrong. Because as you all know, we already know everything there is to know, and just because someone says we can't do it, must mean that we can't.
FTL is probably possible, in fact quantum mechanics does go FTL with it's spooky action, so there is a lot we don't know yet.

And maybe we should stop using resources like there is no tomorrow, that is all this planet does is consume everything, no rationing or even investing heavily into figuring out how to recycle all that junk and plastic.

"proper treatment of scientific uncertainties"

[PJ6]

Both the summary and the article fail to describe the main idea behind what such "proper treatment" is, and that alone was the only interesting thing about the story.

I came here looking for someone with a proper background to weigh in... but apparently nobody who's commented actually read the paper. Oh well.

Re:With morons like Trump "running things"

[mcswell]

Yes, and look where those people are now: Norway, Sweden and Denmark.

Re:With morons like Trump "running things"

[mcswell]

"it's generally considered poor science to assume we're in an unusual part of the universe": Actually, that's the Anthropic Principle, which is also one of the possible explanations (I suppose the only worked-out one, aside from God) for why the constants of physics are what they are.

Time is critical

[aberglas]

For 3,500 million years, life on earth was green slime.

For 1 million years there were humanoids.

For 0.01 million years civilization

For 0.0001 million years, fairly advanced science.

In another 0.0001 million years there will only be robots. (Why would they want us around?)

So the likelihood of stumbling upon little green men just like us is very remote. But it is not so unlikely to find another planet that has green slime, and we my develop tools sensitive enough to detect that.

Remember also that bad things happens to planets. E.g. a passing star swipes them. Over billions of years that becomes more likely.

Also note that soon, intelligence will be robots, and is software. And software can travel in radio waves at the speed of light.

Re:Time is critical

[Immerman]

Nobody is specifically looking for little green men - at interstellar distances they'd be initially indistinguishable from green slime and/or intelligent machines anyway.

Re:Time is critical

[Immerman]

Nope, but they aren't biased against robots.

Re:With morons like Trump "running things"

[Immerman]

Which is a sound philosophical argument, but a lousy scientific explanation - especially once we get into the realm of what we can actually see and measure within the sphere of the observable universe

Yes - sentient life has to arise to recognize its own existence, but why did life arise so quickly on this planet? It may be that there's something physically special about this planet, but the list of possibilities seems quite short and shrinking rapidly as we glimpse other planets and get a statistically better image of the galaxy. And if there is nothing physically special to "jump-start" life here, then there's nothing in the Anthropic Principle to wave away how quickly life arose here.

Re:With morons like Trump "running things"

[mcswell]

I won't disagree about the scientific merits of the Anthropic Principle. I'm actually on the God side of that question.

But about this: "why did life arise so quickly on this planet?", I think a counter-question to that is "why did sentient life take so long to arise on this planet?" The Earth was around for almost exactly 1/3 of the age of the universe before we came. Of course we don't know whether that's unusually long, short, or average, but it is a long time.

Re:With morons like Trump "running things"

[Immerman]

>It is perfectly reasonable to assume that there is life out there which is more primitive, in a similar situation as us or simply different and have no desire to go into space.

Absolutely. The galaxy could be teaming with life no more advanced than us, and we'd have no chance of seeing them at this point. But if they exist, then there should also be others at least a billion years older than any of us. Because our sun is a relative latecomer to the "stars like ours" party.

Re:With morons like Trump "running things"

[Immerman]

Fair enough. For a sufficiently impersonal (theologically) definition of God I might even side with you.

I quite agree - that's an incredibly interesting question. Did it take that long for the cellular infrastructure to evolve to the point that more sophisticated organisms could exist, or did some extremely unlikely event take 3 billion years to occur here to trigger the step to sophisticated multicellular life?

One possibility is that single celled life was still evolving too quickly - the advances in internal cellular mechanisms might have still been evolving at a rate sufficient that multicellular organisms, with their much slower reproduction rate, just couldn't compete for long against new, more efficient single-celled organisms. Not until the advances in single-cell "technology" began to plateau could multicelled creatures really begin to carve a substantial ecological niche for themselves. There is some "worm track" evidence in the oldest rocks to that relatively large large organisms may have slithered across the early Earth.

Re:With morons like Trump "running things"

[Tough Love]

Out [sic[ galaxy is over 100,000 light years across and has an estimated 400,000,000,000 stars in it. A radius of a couple light years and a hundred stars that don't even have life-supporting planets isn't nearly a large enough sample size.

It is large enough to inform us that the universe is not teaming with intelligent life.

Have you also considered that maybe they don't use radio waves (or use radio waves in a conventional manner) because they are either too primitive or too advanced and discovered something better?

Have you considered that maybe they are warmed by electromagnetic radiation just as we are? That they are governed by the same laws of physics as we are? I am curious, what do you think might be better for communication than electromagnetic radiation? Waiting to hear your ideas with tremendous anticipation.

Re:With morons like Trump "running things"

[Tough Love]

By the way, you dropped a zero or two off the stated radius.

Immanent 'reception'?

[GerryHattrick]

Suppose there is a much more advanced 'civilisation' that has become unitary, and that does communicate, and that the 'meat' on this planet is ill-equipped to understand (and our recent tecnology can't detect - it's not 'serial' in time or 'descriptive' in space). Suppose we apes were dimly aware of it, and some of our irrational behavious (dolmens, obsessions, religions...) were the only evidence of imperfect reception. No, I don't belive that at all, but if our Vicar invited this atheist to give a talk, I might not disappoint him.

Re:With morons like Trump "running things"

[darth.hunterix]

"Spooky action" only works if you transfer the information first by slower-than-light channel, Chad Orzel explained it nicely in his books for dogs https://en.wikipedia.org/wiki/...

That said, I totally agree: ignorance is not an argument and our inability to go FTL doesn't prove it's impossible.

Re:Better pray that there's intelligent life up ab

[twosat]

Wow, just literally a few seconds before I clicked on your Youtube link I had been watching the same clip!

Meh

[skovnymfe]

It took 2 billion years to evolve something remotely sentient, then another million years to develop critical thinking, and another 40,000 years to create a civilization capable of talking to the universe. It's likely we're only going to have that capability for a thousand years all together, after which we either become something we can't possibly comprehend at our current level, or we, in our complete ignorance, blow ourselves to kingdom come, and the process starts all over again with another species on another world.

Given these timeframes, how likely is it another civilization just happens to establish itself at the same time, and develop interstellar communcation abilities at the same time, and that they just happen to be close enough for our limited ability to reach them? And how likely is it that they just happen to be listening when we're broadcasting? And how likely is it they hear us and they happen to want to talk?

I wouldn't be surprised if it turns out there really aren't anyone else around to talk to, and won't be for many years to come.

Not going to feed your lazy

[sjbe]

You made the argument, so you need to provide links that support your argument. Is that hard to understand?

If you have time to argue you have time to search. Took you more time to act petulant about it than it would have to actually do the research yourself.

Re:Hypocrites gonna hype, Nazis gonna notsee

[ilguido]

I like when pretentious, know-it-all grammar nazis suck thier own dick:

paper out to boo[t] their careers

That would be an orthographic mistake, not a grammar one.
I missed an "s" when I added a "t" to clarify the original quote that read "boos": I'd use angular brackets to do a substitution, brace brackets for a suppression and square brackets for a restoration (look at Leiden conventions). Obviously that missing "t" wasn't the point of my comment (otherwise I would have not used the restoration symbol), however your snarky comment is and I am grateful to you, because you emphasized the point I was trying to make.

Argument from ignorance

[sjbe]

No it isn't. The point is that this is something where things like nuclear propulsion should work; there's no fundamental physics barrier (unlike say with an FTL system or any other made-up technology).

A dyson sphere (which you brought up) is a fictional technology. We have NO existing technology that would allow us to visit other star systems therefore everything in your argument is de-facto made up technology even by your own description. We have little more than a few thought experiments about how to visit other star systems and we can barely get into low Earth orbit economically. When we actually have a significant manned presence and sustainable economy in space then we can start talking about way out there ideas like visiting other star systems. Your claim that there is "no fundamental physics barrier" is an argument from ignorance by claiming that because something hasn't been proven definitively impossible that it must be possible.

I'm not sure what your point is here. The point that "If X exists, we should see Y. We don't see Y. So this reduces our credence in X" should be straightforward.

We have barely searched a fraction of a fraction of a fraction of a percent of the universe for life. It is WAY too early to start drawing serious conclusions about what we should see based on what we've already seen since we've barely seen anything. Your argument is kind of similar to saying "we've looked at the other 7 planets in our solar system and haven't seen anything so we should conclude that life in the rest of the trillions of other galaxies is unlikely". I understand what you are saying but I think you are making a hasty generalization.

We shouldn't necessarily see them. But if any sort of megastructures are doable,the incentive for an advanced civilization to try and make them will be high.

You could make the same argument about an FTL drive but that doesn't mean it's possible under the actual laws of physics of our universe. Just because you can imagine something doesn't mean it's feasible to accomplish. Lightsabers are cool but good luck actually making one. And even if something is technically possible it isn't always economically realistic. We can and have sent men to the moon but we haven't figured out a way to do so that is economically sustainable so we don't do it anymore. Being an advanced civilization doesn't require the building of structures that are in all likelihood impossible to build.

Moreover, the swarm variants of Dyson spheres and ring worlds don't require intrinsically advanced materials, and don't require that much material.

I get that you really like the idea of Dyson spheres and I'll agree it's a really cool idea. But there is no evidence that any version of them is feasible outside of a science fiction book. It is a thought experiment and in all likelihood nothing more. Lots of really bright people have given the notion a lot of thought and there is no evidence that it is actually possible in the real world. And yes it would require a lot of advanced materials, even for the less resource intensive versions like the swarm. Do you have ANY idea how large even a modest sized star like our Sun is? The circumference of our Earth's orbit around the Sun is nearly a billion kilometers. Where do you expect to get enough materials for even the most modest of habitable rings to exist on that sort of scale? Forget what it would need to be made of, first you have to even find that much raw material. Good luck with that.

Re:Argument from ignorance

[JoshuaZ]

No it isn't. The point is that this is something where things like nuclear propulsion should work; there's no fundamental physics barrier (unlike say with an FTL system or any other made-up technology).

A dyson sphere (which you brought up) is a fictional technology.

The sentence you are quoting was in reply to the statement "Engineering is applied physics so that statement is something of a tautology." Which you wrote in reply to the statement "First, there are no physics barriers to visiting other stars, purely engineering ones." Note that this statement was a statement about visiting other stars, not a statement about Dyson spheres.

We have barely searched a fraction [extremetech.com] of a fraction of a fraction of a percent of the universe for life. It is WAY too early to start drawing serious conclusions about what we should see based on what we've already seen since we've barely seen anything. Your argument is kind of similar to saying "we've looked at the other 7 planets in our solar system and haven't seen anything so we should conclude that life in the rest of the trillions of other galaxies is unlikely".

There's a pretty big difference here at two levels. First, we have searched for all sorts of megastructures- see the link I gave above. And this isn't the only sort of search of this sort done, we've also used Kepler to search for similar signs and haven't found any (with the exception of Tabby's Star which seems to be weird dust.)

You could make the same argument about an FTL drive but that doesn't mean it's possible under the actual laws of physics of our universe. Just because you can imagine something doesn't mean it's feasible to accomplish. Lightsabers are cool but good luck actually making one. And even if something is technically possible it isn't always economically realistic. We can and have sent men to the moon but we haven't figured out a way to do so that is economically sustainable so we don't do it anymore. Being an advanced civilization doesn't require the building of structures that are in all likelihood impossible to build.

Engineering and economic considerations are real certainly, but it is a deep mistake to make the comparison to FTL. That was part of the point: If there's a fundamental physics barrier, no one is getting past it. If a barrier is essentially economic then all it takes is a civilization which is really interested in space travel.

Lots of really bright people have given the notion a lot of thought and there is no evidence that it is actually possible in the real world. And yes it would require a lot of advanced materials, even for the less resource intensive versions like the swarm. Do you have ANY idea how large even a modest sized star like our Sun is? The circumference of our Earth's orbit around the Sun is nearly a billion kilometers. Where do you expect to get enough materials for even the most modest of habitable rings to exist on that sort of scale? Forget what it would need to be made of, first you have to even find that much raw material. Good luck with that.

People have made the calculations for raw material. Dyson swarms and ring worlds are *thin* so it is easy to overestimate how much material they would use. A Dyson bubble, which would in general be larger than a Dyson sphere, requires about as much material as a medium to large asteroid https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_bubble. A Dyson swarm requires much less. As for your statement about really liking Dyson spheres. Not really, they are just one of the easier examples to give that don't require a lot of explanation. In general, there are a lot of different megastructure ideas out there. These are simply some of those which have a high plausibility level.

Think it through

[sjbe]

Volume of Earth: 260,000,000,000 cubic miles.
Length of Earth's orbit: 584,000,000 miles.
Dividing, that results in a cross sectional area of 445 square miles for a ring around the sun, using only the materials of planet Earth. Allowing a thickness of 528 feet, that gives a ring width of 4,450 miles.

A little back of the envelope geometry doesn't equal thinking this through. You are effectively arguing the following:
1) That we could and should turn the entirety of Earth into a ring (seriously?)
2) That all the materials Earth is composed of are actually useful and adequate for such a purpose (spoiler: they aren't)
3) That a thickness and width you calculate (if true since I can't be bothered to check your math) is actually sufficient to be useful
4) That you have a means to provide adequate gravity or simulated gravity
5) You have a means to shield inhabitants from solar radiation and create an inhabitable and sustainable atmosphere
6) How any of this is economically justifiable given the almost unimaginably high cost of such a project
7) How you expect to recreate an entire ecosystem basically from scratch that is well suited to existing in such an artificial construct

Basically even if you stripped every ounce of useful material from our solar system you really would still come up short. And how you would economically justify such a project you haven't even begun to address. Seriously, it's a cool idea in the same sense that a lightsaber is cool but that doesn't make it possible to actually do.

Red Dwarf Got It Right

[wallsg]

I guess Red Dwarf got it right. There are no aliens in the universe.

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[account_deleted]

Comment removed based on user account deletion

Re:With morons like Trump "running things"

[Immerman]

Actually it does. It's almost impossible to meaningfully extrapolate from one data point (such as our own existence), but if life arose dozens or hundreds of times in the galaxy in the time since it arose here on Earth, then we would have a decent estimate of the probability of life arising in a given set of circumstances - and since those circumstances were around for a billion years before our planet existed, we would reasonably expect to see life a billion years older than us.

Re:Better pray that there's intelligent life up ab

[dinfinity]

Same video, but on the actual Monty Python channel: https://www.youtube.com/watch?...

Correction:

[iq145]

There is a 100% chance that there's life on other worlds besides Earth!