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3 Habitable-Zone Super-Earths Found Orbiting Nearby Star
astroengine writes "Gliese 667C is a well-studied star lying only 22 light-years from Earth in the constellation of Scorpius, but it appears to have been hiding a pretty significant secret. The star has at least six exoplanets in orbit, three of which orbit within the star's "habitable zone" — the region surrounding a star that's not too hot and not too cold for liquid water to exist on their surfaces. Astronomers already knew that Gliese 667C had three worlds in orbit, one in the star's habitable zone, but the finding of three more exoplanets, two of which are also in the habitable zone is a huge discovery. Finding one small planet in a star's habitable zone is exciting, but finding three is historic. 'The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star — instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,' said Rory Barnes, of the University of Washington, co-author of the study, in an ESO press release Tuesday (June 25)."
I'd like to get more information about these worlds before I die. Also, I'd like to know if I would really get my own planet if I went "Full Mormon" so I can prepare accordingly.
22 light-years from Earth means that we can't really consider moving there...
Me full Mormon planet too, lol.
Everything is relative. 22 light years, ludicrously far away in every day terms, is a hop skip and a jump in astronomical terms.
I'm still waiting for us to find the five-star system from Firefly. We could use dozens of plants and hundreds of moons to terraform.
Why so? In context of just how freakin' big a galaxy or the entire universe is, 22 light years is pretty damned close. The Milky-way alone is > 100,000 light years across.
Not even 25 years ago the prevailing belief was that there wouldn't be that many stars with planets, and now we're finding them pretty much constantly.
One of the terms of Drake's equation is how many stars have planets, and that proportion has been steadily climbing.
So if we're finding this many planets in an astronomically-relative 'nearby', then throughout the rest of the galaxy we have to assume there's just vast amounts of them. Start factoring in the sheer number of galaxies, and even if we'll never meet them, it seems probable that somewhere else would likely have evolved life by now.
Lost at C:>. Found at C.
"nearby" is relative. At 80 miles, the beach is nearby relative to, say Germany. But I still wouldn't want to walk there.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
I think I will be avoiding the peacekeepers thanks.
'The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star — instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,' said Rory Barnes, of the University of Washington, co-author of the study
While seemingly true, this statement is misleading. Having found 3 habitable planets around a single star, it does not follow that all stars have 3 habitable planets. Or even that any other star has 3 habitable planets. I really hope this was just a statement made out of context...otherwise...it just makes me sad.
There are many exoplanet claims with both the transit method and the Doppler method. What I'd like to see is use them in the same systems to see whether they yield the same results. Right now, these are only predictions, not discoveries, and they are hard to verify.
One problem that has not be determined is how do planets deal with the inherent variability with Red Dwarf stars. There are many, many more red dwarfs than other types of stars and their expected life expectancy is longer the estimated end of the universe. But their small nature makes their energy output more variable than a star like our sun.
Does the long life, and greater number of Red Dwarfs significantly boost the drake equation? Does the variable energy output reduce the drake equation?
Unfortunately, we will all probably be long dead before we find out.
After launch, if there was a method to constantly accelerate then decelerate an exploratory robot around 1g, it would take about a year to approximate the speed of light and another to stop. Without any screw ups, the transmissions of its observations of the planets would be received within 50 years. Still not close. Just sayin'.
It took us 200 years to increase normal-ish transport speeds from 5mph to 500mph. (Though bulk transport is still more like 30mph.)
We've got a LOT of technology to develop if we want to increase normal-ish transport speeds from 500mph to 1/2 light speed.
It's just about a million times faster than current tech. Even if you assume we get 100x speedup every 200 years, that's another 600 years of tech, though of course I concede that development doesn't need to be 100x every 200 years.
Making this even worse is the fact that energy required (nonrelativistic) goes as v^2. So we need ~10^12 as much energy to move stuff at 1/2 light speed (actually worse due to the relativistic factor.)
Your confidence in technology is nice, but I for one find the numbers involved downright sobering.
--PM
There's plenty of data both pro and con about sending a probe to explore and the timeline necessary. Has anyone ever thought about seeing if perhaps another race has sent a probe at us? And if so, how would we spot it?
Here's to hot beer, cold women, and Glaswegian kisses for all.
Not even 25 years ago the prevailing belief was that there wouldn't be that many stars with planets
Was it?
Right now it doesn't matter if it were 1.5 light seconds away. We can't get there. It may as well be in another universe. By the time we can conveniently travel that far, the whole concept of distance will be meaningless. For the sake of argument, yes, 22 light years is closer than 13 billion, but for now, in practical terms, the distance is infinite. If you already bought your ticket, I would suggest you ask for a refund.
“He’s not deformed, he’s just drunk!”
But that is the good thing about space travel. You can't walk.
Well, we have already proven we can get 1.3 light seconds away, land and return.
I think in the context of the Fermi Paradox finding lots of habitable planets is _bad_ news because it invites the question "so where the hell is all the intelligent life on all these habitable planets" the aswers to that question indicate a term in the drake equation is close to zero, hopefully it isn't the term that indicates the length of time a technological civilization exists....
Bullshit, you didn't even get your numbers right with that hyperbole. Orders of magnitude are tough, but not entirely unworkable.
Mars is 22 light MINUTES away, and we can get there reasonable well if we had a mind to.
If you can get up to a decent fraction of the speed of light, energetically very expensive I'll grant you, a ship could get to one of these worlds in 100 years or so. That's a long time, but it's not so long as to be considered infinite or unworkable. If you take the point of view that's it pointless to consider how far our grasp can extend, of course we'll never get there.
Right now it doesn't matter if it were 1.5 light seconds away. We can't get there. It may as well be in another universe.
1.5 light seconds is roughly the distance to the moon. If we had another Earth like planet that close (assuming a somehow stable orbit and ignoring geological and evolutionary impact) you could be vacationing there right now.
It's great news that so many planets are found, and obviously the chances of extra-terrestrial life are higher if there are more planets, but saying that such life is "probable" is pure speculation. We still need to know under what circumstances life can start and how likely it is to get going given the right circumstances to calculate the odds. Until then any guess is just a hunch. No matter how many planets there are, it's still possible that the odds against life is greater.
Errr. Yes it does. 1.2 light seconds is closer than the moon - so we could get there.
I don't know...1 light second is 186 282 miles which isn't THAT far
Ummm, the moon is 1.5 light seconds away, and Mars is 4 light minutes away. We can, and have, send stuff to both of those, so 1.5 light seconds isn't this intractable distance you think it is ... if you were walking it would essentially be infinitely far away. But with rockets from the 60's it was more like a few days.
I'm not suggesting we're going to reach these any time soon, but you have to remember that relative to the scales we're talking about, 22 light years in astronomical terms is a very close distance.
I haven't bought a ticket, but you need to re-think your concept of what is 'infinite' and what kind of distances are truly insurmountable.
Lost at C:>. Found at C.
Right now it doesn't matter if it were 1.5 light seconds away. We can't get there. It may as well be in another universe. By the time we can conveniently travel that far, the whole concept of distance will be meaningless. For the sake of argument, yes, 22 light years is closer than 13 billion, but for now, in practical terms, the distance is infinite. If you already bought your ticket, I would suggest you ask for a refund.
22 years means you can send a message and get a response in your lifetime.
1.5 light seconds is roughly the distance to the moon.
And when was the last time we had humans on the moon? Distance doesn't matter all that much when we don't care enough to continue exploration of what's already reachable.
But even in space "nearby" is relative. We can reach Mars in a reasonable amount of time, using technology that's the space equivalent of "walking". Reaching even the nearest star is a whole 'nother story. Something else needs to be invented in order to achieve that. Or as someone smarter than I once said:
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”
(Well, who did you *think* I was going to quote??)
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
267,709
The Fermi Paradoxon is no paradoxon.
The most evil sin all over the universe is: man made self replicating machines.
No sane race ever will do that: crafting self replicating machines and letting them lose on the universe.
In the time spans we are talking about: all things you could imagine will go wrong with "replicators". You don't need to read SF to grasp that. At Fermis times no one really thought that out. So his idea is sticking Round as "paradoxon".
Would YOU with all the SFs you have seen support a "self replicating" machine being send to another star system? Just to multiply there and go on?
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
I'm not sure what difference this makes to the actual habitability of the planets, but all of these are tidally locked. That is, the same part of the planet is always facing the star (and thus baked) while the same part faces empty space (and thus freezes). A thick atmosphere might transport heat and make things more uniform, but none of these are what one would naively think of as "habitable". In fact, all planets in the "habitable" zone of such small stars are going to be tidally locked. Wikipedia actually has a nice summary of the problem of tidal locking in small stars.
On the other hand, they might have very interesting moons.
and its sister stars are only 4 LY away. One would think we'd have gone over them with a fine tooth comb and all we've found is 1 molten hell hole around Cb. Why? Wouldn't even a smallish planet be a lot more visible around AC, Cb, or pC than some galaxy 13.6 billion LY away?
Shoes for Industry. Shoes for the Dead.
I feel like this submission title has greatly lowered the bar for "habitable."
I think in the context of the Fermi Paradox finding lots of habitable planets is _bad_ news because it invites the question "so where the hell is all the intelligent life on all these habitable planets"
Obviously you're unaware of Oliver's Solution to the Fermi Paradox: They discovered reality tv. Then civilization collapsed.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
There are no humans on the Moon because there's nothing to do on the Moon. There are only so many kilos of regloith you can ferry back and rounds of low gravity golf you can play before there's no point spending the billions to go back. If and when someone thinks up a useful reason to go back to the moon (e.g., a way station for missions to further afield) then I'm sure we'll be back.
If the Moon were an Earth-like world, I'm sure there would be a McDonalds serving Moon Burgers up there by now.
We're finding enough potentially habitable exoplanets that it's worth sending messages to them. Some might have a civilization. It's time for SETI to start transmitting.
This is quite possible. Arecebo could communicate with a similar installation across the galaxy.
Assuming they have SETI, right?
I'm excited about the news of habitable planets being more common-place in our galaxy (and probably the universe) than previously thought. The thing is, WHEN are you people going to stop this big bang and evolution nonsense ? Every time scientists discover that the potential for life is greater in greater, you do realize that they're also proving that creationism is more and more likely than evolution. The reason is that, the more habitable planets that exist, the more I question WHY we haven't seen any visitors yet or seen any evidence of their existence? We can't get to them but, if our universe is most likely teaming with life, I would think we would have made contact by now.
The reality is that God created life ON EARTH.
The 'insurmountable' doesn't exist. The impractical is a little different. And to me, without faster than light travel, dragging our meat bags around to 'nearby stars' does not seem practical. I will grant that only greed and politics prevent regular service to the moon, it is they that make it seem as distant as an extrasolar planet.
“He’s not deformed, he’s just drunk!”
No sane race ever will do that
So, homo sapiens will be the first.
For instance if you were to ping a space craft in orbit, the latency would be 44 years.
Yes, but 'getting to' is not the same as 'landing on'. Or do you want to land at a decent fraction of the speed of light?
I rather liked the sci-fi "Fermi Answer" given in Ian Douglas's Heritage/Legacy/Inheritance trilogies: a xenophobic race with a massive Darwinian survival complex decimates every other species that gets close to star travel technology and literally bombards them back into the stone age.
Or perhaps even more likely there's just nothing to detect out there because their "indistinguishable from magic" technology doesn't operate in ways we can detect and all of their EMF shells from bygone eras passed us long ago. And they just have nothing to say to a bunch of primitives like us.
I don't think sending self replicating machines would be any more "evil" than sending the self-replicating people that would design them. With a machine you could at least tell it not to wipe out an indig population in an conflict over mutual survivability. You can't expect the current model of humans to do that.
"The Adobe Updater must update itself before it can check for updates. Would you like to update the Adobe Updater now?"
It's essentially guarenteed that we're not alone in the universe.
500 billion galaxies.
300 billion stars in the Milk Way alone (which is either an average, or even a small-ish galaxy)
At least 10 planets per star we're thinking (we only have 8, and we're relatively barren we think).
So like, 1.5 quadrillion planets. Then you need to factor in moons for those planets. 10 per, maybe? Earth only has 1, but we're the exception - Jupiter has 67 moons - and our planets are relatively small because we're a relatively small system - a super-earth would likely have many moons each with a high likelihood of Panspermia.
Large stars likely have way more planets than small ones, and bigger planets as well (based on Kepler equations for likely orbital/mass relations), bigger planets likely have more moons and bigger moons. So, the Sol system (our own) only has 8 planets and like 100 moons - but think about the system of planets that must orbit something like Antares or Betelgeuse (let alone VY Canis Majoris) - potentially there could be hundreds of planets in a single system, each with tens if not hundreds of moons.
The odds that we're alone in the universe are at best 1 in quadrillions: pretty unlikely! It's at the point where it's feeling silly to even keep debating it.
Passengers on a manned flight at 1g acceleration/deceleration would experience it as only 6.2 years according to this.
Yes, it should also be noted that we've put no humans on the moon but NASA, ESA, Japan, India, China have all had missions to the moon since and Russia is also planning new missions after they stopped the Luna program in 1976. Mostly what we lack is a compelling reason to send people, it's been done and even repeated a few times so it's a bit like after the first 10 people had been on Mount Everest there's not really much to be proven that we could climb it again. I'd say go straight for Mars, break some new ground not just revisit the old ones.
Live today, because you never know what tomorrow brings
100 years of travel for 22 light years away.
That's 50 years of acceleration and 50 years of deceleration to travel 22 light years.
So you have to accelerate for 50 years and travel 11 light years in the process.
What's the calculated acceleration?
22 light years is 208,200,000,000,000 km.
Average speed to get there in 100 years is 208,200,000,000,000 km divided by 3,153,600,000 seconds, that's 66019.8 km/s. You need to reach that speed in 25 years of acceleration. That's 0.08 m/square second. Easily achievable, provided you don't have to carry half of Earth's mass in fuel. I think even ionic drives can get that sort of acceleration.
Ideally, considering an acceleration of 1g (constant, disregards time spend in orbit or maneuvering around, etc) you could reach 283,940 km/s in exactly 11 months (335 days).
Now all we have to do is come up with a perfectly working Bussard reactor... (http://www.ibiblio.org/lunar/school/InterStellar/Explorer_Class/Bussard_Fusion_systems.HTML)
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Given that the only solar system we have even partially explored has at least one potentially habitable planet, why is the constant assumption made that te vast majority of other systems are entirely uninhabitable? Are we really THAT arrogant to think our system is so unique? Based on the evidence in our sample size of one, surely the logical assumption would be that there are plenty of other similar systems?
I run: Windows, OS X, Linux, FreeBSD. Just because you have a hammer, doesn't mean everything is a nail.
Self replicating machines don't have to be intelligent. Even if they only replicate some kind of marker or beacon to plant as they go. The only way to get ahead of the sheer numbers is to spend time planting seeds and signposts with directions to the other habitable planets. Give races something to shoot for and see if they show up.
For every habitable but uninhabited planet we find, the human race becomes more and more special. I don't want to be that special kid...
Dude, I never said it was practical, or that we'd be doing it.
This is an article about astronomers discovering new planets. In their parlance, they are 'nearby'.
Nobody is saying "close enough to get there", they're saying "holy crap, on a galactic scale, that's pretty damned close".
The insurmountableness of the distance isn't what's the point, because nobody is yet talking about surmounting it. The cool part is that they've found it, 3 of them in fact, a 'mere' 22 light years away, all of which could be in the zone where liquid water could exist.
The universe must simply be teeming with planets which have the potential to have life as we know it (or at least chemically similar enough that we can postulate its existence).
We may not get there, but at this moment light from Sol which left in 1991 is reaching these planets.
That, my friend, is some heavy shit.
Lost at C:>. Found at C.
There are a lot of potential answers. Many of them are negative, but some of them are only "sort of" negative. E.g.:
1) The population is plugged into the local analog of the cloud, and doesn't want to put up with the low latency required by interstellar travel.
2) Artificial environments are so much nicer than natural planets, that nobody is interested in them.
3) TV is already one of the more effective suppressers of birth-rate. The internet is a close second. So populations just stop growing. People have more interesting things to do than taking care of kids.
4) An authoritarian government doesn't want to allow colonies to escape to breed rebels. And it's effective. (N.B.: This could be a welfare state, a plutocratic state, or any of various other varieties, and perhaps different planets have different choices.)
5) Perhaps many races can't live in low gravity, or can't stand the stresses of liftoff.
There are, of course, lots of more negative answers, like resource depletion, gray goo, etc. But we don't need to presume that the answer is always the same, or even that we know all the potential reasons yet. I've heard one argument from economics that because of intrest it's impossible for any interstellar colony to ever pay off the costs of founding it. Maybe. Or maybe that's just another hurdle that makes things more difficult. Many species may have a fear of heights or of falling that makes space flight unendurable.
Note that each of these answers only reduces the proportion of races that will engage in interstellar flight....or at least will impinge on us after doing so. And there are many other answers.
Here's another one: We may be among the first generation of planets with enough heavy metals to produce a form of civilization that can lead to space flight.
That said, do note that "super earths" are not a good place to develop spaceflight. The Earth itself is heavier than optimum, but this much gravity may be needed to hold onto viable development conditions. And how important was the moon? Some arguments have held that not only the existence of the moon, but the way that it was captured is crucial. (Note that it stabilizes the Earth's axial tilt.)
So, while I find the Fermi Paradox troubling, I don't find it insoluble.
I think we've pushed this "anyone can grow up to be president" thing too far.
And I thought my internet was slow in the 90s.
if you accelerate constantly a 1g for 11 light years and then decelerate at 1g fo 11 light years it takes 9 years to get there in your rest frame. in earth frame time this is much longer so you cant just come back in 18 earth years, but you can come back in 18 of your own.
Some drink at the fountain of knowledge. Others just gargle.
Moving from subsonic to supersonic speeds, the efficiency of wings, falls by more than a half. The energy efficiency of thrust also falls by more than a half from high subsonic turbofans, to mach 2 turbojets. The Concorde gets ~17 seat miles per gallon. A modern airliner get ~75 seat miles per gallon. Fuel consumption also effects range. So, there is a reason the United States does not have any supersonic bombers. Fuel costs might go higher in the future, and there is talk of modern turboprop airplanes that travel ~400 mph, with higher fuel efficiency.
Big planets would likely as not be volcanic hell-holes with crushing atmospheres due to greater gravity.
Too bad at least one of these planets is already inhabited by a sentient species.
Maybe we deserve this world ?
By definition, no sane race other than humanity could ever create man-made self replicating machines.
On the other hand, organic life is made up of self-replicating machines.
That is why we have the Butlerian Jihad to free humanity from thinking machines. "The mind of man is holy".
liberare massarum ex ignorantia, clausa descendit molestie.
We don't seem to have intelligent life on our own planet, why expect it on any other planets?
Relativistic journeys calculator here: http://www.cthreepo.com/lab/math1/ Gives 6.2 years (moving frame) or 24 years (earth frame) to get there, assuming constant 1G accel, deccel. I've spent longer (subjective) than that waiting for a British train.
As you get closer and closer to light speed the energy required to keep a constant acceleration rate goes up exponentially. So it's not easy to keep a steady acceleration rate of 1g. This should be true for all propulsion methods that shoot stuff in the opposite direction of where you're going.
The technology to feasibly travel 22 light-years and FTL technology are not even remotely comparable. Right now we have neither, but those discoveries will be many generations apart, if the latter is even possible.
Does the calculator account for speed of light limitation? (you can't go faster that 296K km/s)
I think it does, my manual calculations got me pretty close to that.
Ideally, for a human crew, the ship should alternate acceleration and deceleration so that the perceived gravity is always at 1G. Otherwise, you would accelerate for 1 year, then spend 4 years in zero gravity, then decelerate for 1 year at 1G, which is highly NOT recommended.
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Others have chewed over this calc in more detail, different subthreads. To increase perceived G you can always spin the ship. Also, the relativistic round trip doesn't require high peak acceleration to be doable in 6.2 years moving-frame, but it does require *massive* speed: as others have said, once you have got up to 0.6c (relative to the galactic frame) the vague fluff of stray protons etc that are floating around in deep space starts to look like concrete. The main problem for the moment is reaction mass: the Apollo rockets were mass ratio > 19:1 [(fuel+reactionmass):(everything else)]. To burn for twice as long you need to square the fuel, because you are also carrying your reaction mass. There is a lot of loose talk about ramscoops, but they seem like a pretty insane engineering challenge: the practical solution that seems more likely is to develop a super-dense energy storage technology like antimatter, so that reaction mass can be pushed out harder and we don't have to carry as much of it. Once that happens, ramscoops might be the next step but interstellar probes at least would start to make sense without them. AFAIK a human-survivable round trip to gliese (20-40 years, moving frame) would be doable quite soon using nuclear engines such as UF6-water design.... but those babies are not certified for terrestrial launch. Frankly I wouldn't even want one in orbit around my home planet thankyou very much.
With a round-trip-time of at least 2x22a to, lets say a rover, you really have to resort to mosh in oder to ssh into that box.
It has to be the timespan of technological civilization. For all we know, there should be no proper civilisation on Earth in few hundred years. Tragedy of the commons will make sure of that. It makes sense for everybody to exploit Earth in short term instead of trying to branch out to space in any real way. And when at some point it will be obvious that it doesn't scale, there will be not enough free/cheap resources available to make that jump. And then big asteriod will appear...
That is, if we don't nuke ourselves into oblivion beforehand in name of some ancient deity...
Putting 1000 people on Mars/Asteroid Belt in self-sustaining environment would probably cost same amount (of cash/energy/resources/whatever) as feeding billion of people on earth for their lifetimes. As long as people think that maximizing earth population is overall goal of mankind, there is no chance of any change. And we have it encoded in our genetic and memetic makup. And probably same happens for every civilization out there.
Regarding self-replicating probes... We might have been hit by one 4 billion years ago - DNA+microbes are a lot better nanomachines than clockwork automatons.
And how important was the moon? Some arguments have held that not only the existence of the moon, but the way that it was captured is crucial. (Note that it stabilizes the Earth's axial tilt.)
So, while I find the Fermi Paradox troubling, I don't find it insoluble.
Interesting point. But from a sample of one, one cannot do science. As the planet formation models from before the exoplanet discoveries show, one cannot do viable science based on a sample of one.
Here is how it will work: we will be able to detect spectra of planets within the next 50 years. Based on that, live will be found on many, few, or none. Based on that the models will be adapted, and all nerds on /. in 2060 will fail to understand how we in 2013 did not see how it all really worked, as it's so obvious.
Some arguments have held that not only the existence of the moon
One of my favorite ruminations of this sort is in AE Van Vogt's "The Voyage of the Space Beagle". At one point the titular intergalactic ship lands on a remote planet on the rim of the galaxy, which has only a single rocky planet with no moon. A highly advanced civilization once lived there but died out - because they had no moon, no nearby rocky planets, and no stars with planets within hundreds of light years. So they had no "stepping stones" to develop interplanetary travel, and never made it to interstellar travel. Humans, on the other hand, were able to mount a manned mission to another body within 70 years of developing flight - just because it's so damn convenient. And Mars provides a convenient (if vastly more difficult) next step.
...Or a Bussard Reactor, which uses interstellar Hydrogen as fuel. Basically, you don't carry the fuel with you, but gather it as you go. An even more interesting feature is that the faster you go, the more fuel you get...
Of course, this all is highly theoretical at the moment, but finding super-Earths so close (astronomically speaking) should only encourage research efforts in that direction.
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Passengers on a manned flight at 1g acceleration/deceleration would experience it as only 6.2 years according to this.
AC's get no respect, especially when gamers can game their replies for mod points by trumping the original post about an an idea above your comment. If you're into moderation rep, then guessing the right comment to reply to is a gamble. Better luck next time.
Yesterday's Weirdness is Tomorrow's Reason Why
There are no humans on the Moon because there's nothing to do on the Moon. There are only so many kilos of regloith you can ferry back and rounds of low gravity golf you can play before there's no point spending the billions to go back. If and when someone thinks up a useful reason to go back to the moon (e.g., a way station for missions to further afield) then I'm sure we'll be back.
If the Moon were an Earth-like world, I'm sure there would be a McDonalds serving Moon Burgers up there by now.
There's cheese. Billions of pounds of cheese we could be mining.
22 light years... These guys have seen the entire run of MacGyver by now. Let them figure out how to get here
“He’s not deformed, he’s just drunk!”
OK, so I gave a crude, nonrelativistic calculation of how much energy increase would be required to accelerate from 500mph to 1/2 the speed of light.
I came up with a number, based on the nonrelativistic equation "E=1/2 m * v^2" and added the remark that my estimate was off because of my neglect of relativity.
I explicitly deny that "goes up v^2 because of friction" is true. Furthermore, the relativistic equation isn't even that hard. Let's start with this:
E_kinetic = m * (gamma-1) * c^2 where
gamma = 1/sqrt(1-v^2/c^2)
For 1/2 speed of light, (gamma-1) = 0.1547.
For 500mph, (gamma-1) = 2.78 x 10^-13.
To compare the two, note that
E_kinetic(1/2 c) / E_kinetic(500mph) = (.1547/2.78x 10^-13)
which yields an energy ratio of 5.56 x 10^11.
So to increase "normal" transport speeds from 500mph to 1/2c, we only need to use 556 billion times more energy.
--PM
Well there are inhabital planets we can use if we screw up ours. Thats good and all but how do we get there? 22 light years is a long way. We'd need a faster than light speed meens of travel or a neer light speed travel and advance cryopreservation technology.
Well there are inhabital planets we can use if we screw up ours. Thats good and all but how do we get there? 22 light years is a long way. We'd need a faster than light speed meens of travel or a neer light speed travel and advance cryopreservation technology.
Well, I must say I'm really grateful to you for the perfect demonstration of the Dunning-Kruger effect.
This is it:
From Wikipedia, "The Dunningâ"Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average."
And you're an extremely illustrative case, because even though about four people told you that you were wrong (some more politely and some less), you PERSIST in your belief that E != 1/2 m v^2 (approximately).
I mean, we collectively didn't even manage to inject enough doubt into you that you'd take the trouble to look it up instead of continuing to support your mistaken position in public. Either you're a troll, or you're a REALLY textbook case of Dunning-Kruger.
As for your car, do you REALLY think that you use the same energy every second, continuously and linearly like you claim? I mean, don't you HEAR the engine rev up to higher RPM before it (or you) shifts gears down again? D'you know what that higher RPM means? It means more power (and power, for your information is defined as energy per time).
As for my calculation of some 500 billion times more energy required to accelerate to 1/2 light vs. 500mph, I showed my work, and you can find the basic equation I used on:
http://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies
Anyway, I'm going to see if I can preserve this thread as a case study in Dunning-Kruger (or perhaps internet trolling), though even if you are a troll, it's STILL a great demo of Dunning-Kruger.
--PeterM