Finding Twin Earths Is Harder Than We Thought

Matt_dk writes "Does a twin Earth exist somewhere in our galaxy? Astronomers are getting closer and closer to finding an Earth-sized planet in an Earth-like orbit. NASA's Kepler spacecraft just launched to find such worlds. Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere? Answering those questions will not be easy. 'We'll have to be really lucky to decipher an Earth-like planet's atmosphere during a transit event so that we can tell it is Earth-like,' said Kaltenegger. 'We will need to add up many transits to do so — hundreds of them, even for stars as close as 20 light-years away.'" The abstract of their paper offers a link to the complete paper as a 17-page PDF; here is a short description from 2007 of the same researchers' work, outlining the type of spectral signature that an Earth-like atmosphere would be expected to show.

Comments

Solution:

[Anonymous Coward]

Build in a FTL drive and have Starbuck magically... oh fuck it.. what a cop out. :\

Re:Solution:

[Mistshadow2k4]

There must be some kinda way out of here...

Said the joker to the thief.

(Unfortunately, neither seems able to provide much help on FTL travel.)

Re:Solution:

[CarpetShark]

Build in a FTL drive and have Starbuck magically... oh fuck it.. what a cop out. :\

I'm guessing you've never heard of the probability drive.

Re:Solution:

[CarpetShark]

Never mind; neither have I :) Correct name is Infinite Improbability Drive. Look it up anyway; it's fun :)

Re:Solution:

[collinstocks]

Oh, please. This was superseded by the Bistro drive years ago! It gets rid of all that mucking about with improbability. Much safer.

Re:Solution:

[Quantos]

My son was involved with a Boy Scout bottle drive once. I'm positive that it might help....
*tips head to the left to listen to the voices...*

Re:Solution:

[Aklyon]

but it was made by a non-infinite Probability Drive, so is it really Infinite?

Re:Solution:

[mokus000]

Safer?? Obviously you've never tried to settle the bill in a large party at a bistro.

In effect, what they are saying, is

[Jane Q. Public]

that it will take hundreds of years to tell if they are truly Earth-like. And that is complete nonsense.

Once we find a sufficient collection of candidate planets using this instrument, we can devise a different device/experiment to narrow down whether they are Earth-like. That should take maybe a few years to ten years.

That is more-or-less the pattern we have been following, and it has been successful so far. I see no reason to change.

Re:In effect, what they are saying, is

[Vectronic]

"...and it has been successful so far. I see no reason to change."

Has it? Can we really be sure that the current method is accurate in ruling out earth-like and non-earth-like?

I'm not really disagreeing with you, just not so sure that it's 100% accurate (which is ideal, but not exactly realistic). To me this sounds like they are intentionally thwarting the idea, so the public will go "well shit, guess we're trapped here for 300 more years" kinda thing.

Current method seems fine, applied to the new equipment. Keep searching, monitor the ones we already assume are earth-like, and when we figure out a way to do something about it (wormholes, etc) we pick the best candidate at that time, and go for it, if that fails, or if it takes longer than the time to build/induce/etc the next method of travel/communication, we head for the second candidate, etc... this "new" method seem to suppose that we won't be able to do anything about it for 200 more years, so we have the time to piss around with hundreds of tests, when we should probably assume it'l be possible next year, kinda like "Year of Linux on the Desktop", may never happen, but why can't it happen next year? Just because you may not succeed, doesn't mean you should't try.

Re:In effect, what they are saying, is

[TapeCutter]

I was 10 when I watched Armstrong land on the moon, every kid was into space and I had read "grown up books" in the library with pictures of water canals on Mars and rainforests on Venus. Since then astronomy has been fully digitised and we have mapped most of the EM spectrum. I'm not saying it won't continue to improve (especially in the area of corrective optics) but I think it will be slower now that the spectrum land rush is coming to an end and digitization is well and trully complete.

The long term limiting factor with all astronomical technology is signal to noise, there have been huge advances in my lifetime concerned with the accuracy of finding and ploting the signal, but you still have to collect the photons. Mirror making tech is old tech but even it took a big jump in the seventies, I remeber reading how they made the mirror for Hubble sometime in the late 70's. It's the gold standard for mirrors (~1mm deviation over an area the size of Australia), I know, pity it was the wrong shape.

Thing is, the electronics are now that good that we no longer need large mirrors with that degree of accuracy, we can larger less accurate mirrors and then correct for known distortions, even real-time chaotic ones such as atompospheric wobbles.

I don't think Kepler will be a situation where someone announces "the answer", the best "iconic image" we will have to print on our T shirts will be a spectrum. How long it takes to get to the T shirt stage depends on how many candidate planets, their orbits, the number of photons we can catch and plot, and most of all, how confident do you want to be about yes/no.

Re:In effect, what they are saying, is

[Nyeerrmm]

From what I can tell in a brief skim, it really does pose a fundamental limit given current technology. The problem is that with the largest mirror we can imagine getting up into space, and with the highest sensitivity sensors, the signal-to-noise ratio is still too low to get a usable measurement without taking hundreds of measurements.

They plan to detect the chemicals in the atmosphere by measuring the absorption bands in the starlight as some of it passes through the atmosphere. This is presumably going to be a lot more sensitive than trying to detect the light from the planet directly, since you have a lot more photons to carry the information. The signal to noise ratio in this case is really limited by the unfortunate fact that light energy is discretized and you can't make finer measurements than a single photon. Thus a large mirror with a high-quantum efficiency (95%) sensor, is really the best you can do.

The only hope to improve this is to either get bigger mirrors, which really depends on improving space access and is unlikely to give order of magnitude improvements, or to implement an as yet unrealized method that is able to get more information. If it were a problem of angular resolution there are plenty of interesting tricks you could use to improve it. Unfortunately I can't think of anything better, and it doesn't seem anyone else has yet either. Of course, that doesn't mean no one will... but its not as simple as just designing the next mission.

Actually... random 3:30 am idea... if you did something in thermal-IR, and measured the absorption of the blackbody emissions of the planet by the atmosphere you might be able to get something working. The intensity would be a lot lower than looking at the stars light, but the dimming due to absorption would be much larger percentage-wise... although it would take some heavy math to show if it would actually give you a better SNR. Of course, there are plenty of holes here: among other things, my knowledge of atmospheric chemistry and absorption is very limited, and this would all depend on being able to resolve the star separate from the planet, and would thus rely on some complicated interferometric methods....... and you'd have to block out the star light to be able to get the planet light as anything more than noise... and probably the number of photons in thermal IR from a planet are too low to be able to even see it on its own... but maybe I'm wrong and it could work, or something else can.

Re:In effect, what they are saying, is

[MrKaos]

we can devise a different device/experiment to narrow down whether they are Earth-like

I don't know if this is valid but, what about 10 devices doing the same job?

Re:In effect, what they are saying, is

[Z00L00K]

Just because it's hard doesn't mean that we shall give up trying.

This field is still a very young field, and the methods used to find planets will be more and more refined over time.

But it's also important to not count out stellar systems that may not look like they are going to contain earth-like planets. Even a negative answer is an answer giving usable data in this case.

Earth is the only speck of dust in the universe where we are certain that there is life. If it's intelligent enough to prosper in the long run remains to be seen. Considering the chemical processes seen in other places in the universe it's likely that life exists elsewhere, but in different forms from what we see here. It would be extremely surprising if we were to find life on an earth-like planet that's similar to us down to the DNA/RNA level.

What humankind need is to continue to find ways of understanding the universe and how to best utilize the possibilities and circumvent the problems.

Re:In effect, what they are saying, is

[MrKaos]

I don't know if this is valid but, what about 10 devices doing the same job?

Huh? Why is modded a troll?

Re:In effect, what they are saying, is

[forand]

IAAP (I am an astro-physicist) and while I would love to agree with you, I cannot. The problem is not that we do not know how to get a quick measurement the problem is that is would take huge sums of money as well as very significant technological improvements.

Science is being limited much more by funding and physical constraints. Current ground based telescopes are operating very near the quantum limit and space based observatories are expensive to the point of making them infeasible.

All in all I think that pointing a few telescopes at a given object for long periods of time for a total cost far exceeding that of building a better solution is the path that is being (and will continue to be) pushed on the scientific community. The prices tags for what we want to know are so large and budgets tend to be sabotaged by political agendas as to make it appear that we are incapable of doing science for a reasonable price.

Re:In effect, what they are saying, is

[radtea]

just not so sure that it's 100% accurate( which is ideal, but not exactly realistic)

"100% accurate" is not the ideal because things that exist are better than things that are not, and no test that exists will ever be 100% accurate, so there will always be a better test: the one that actually exists!

It would be silly to have a test that was "better than ideal", so obviously the ideal test is the best one we can actually build, not the best one we can imagine. Our imagination is not the arbiter of quality. Reality is.

Re:In effect, what they are saying, is

[Anonymous Coward]

I've said this before, but: use gravitational lensing for your "lens". Put a telescope at the "focal point", point at the sun, and null out the sun itself from the pictures you take - now you have a "lens" the size of the sun. Too bad the relevant point to put the telescope is at 500-1000 AU.

Re:In effect, what they are saying, is

[iminplaya]

Science is being limited much more by funding and physical constraints.

Then we have to mechanize the process, completely, from rock to finished product. Economics won't matter if human effort is not involved.

Re:In effect, what they are saying, is

[Mal-2]

Better yet, 10 devices working 10 different targets. When one is found that is particularly interesting, the other nine drop what they're doing and chip in.

Mal-2

Re:In effect, what they are saying, is

[yusing]

I am half-astrophysicist. I sympathize with your need for much more money for what you want to know, I am the same way with sex - very very curious and a deep need to know.

I guess I need to point out that most Americans also need much more money. Not to (ever) mention the rest of the world.

And so your dream is not likely to be realized by wanting much, much more money. So, like me, you'll have to find clever ways to accomplish your need to know that don't require much, much more money - using your imagination!

As much as I'd love to find another Earth...

[palegray.net]

If they're at a similar point in the evolution of intelligence, that's kinda scary in a way. Maybe they've already made the jump to a pervasive machine intelligence; that would probably be less distressing.

Re:As much as I'd love to find another Earth...

[physburn]

Not surprising your scared for Aliens. But the chance of nearby planet being at a similar level of evolution is very slim. On earth life took, 4 billion years to form civilisation. Yet a space faring race could fill the galaxy in a million years. Not at all sure why you find machine intelligences less scaring than biological ones. Both can chew up resources very quickly. Are the laws of economics different for a robot?

Extra Solar Planetsdaily items at FD.

Re:As much as I'd love to find another Earth...

[Farmer Tim]

I'm fairly certain that the little green men, ticked off after years of being depicted as scrawny, bug-eyed, space-faring bobbleheads, will just come in rayguns blazing, but the machines, prizing efficiency and precision above our human failings, would probably arrive and play muzak with a pre-recorded voiceover telling us that our death is important, and would we please wait.

Is being blasted into your component molecules by unimaginably powerful energy beams really more distressing than being put on hold?

Re:As much as I'd love to find another Earth...

[palegray.net]

Not at all sure why you find machine intelligences less scaring than biological ones. Both can chew up resources very quickly.

To put it simply, the more advanced a system becomes, the less resources it tends to require per cycle of computation (not the best way of putting it, but hey, I've had a few beers). Now, there comes a point in the acceleration of intelligence where virtually everything in sight has some sort of information processing capacity associated with it, and everything's linked in a pretty mesh-like way. That's where things get interesting: the convergence of increasing efficiency in computation, with a simultaneously increasing level of efficiency of computation, combined with an exponentially increasing density and commonality of computing "devices." It's already started to happen at a noticeable rate, and has really been occurring since human beings first scratched meaningful symbols in clay tablets that would outlive their creators. Fun times to be living in.

Re:As much as I'd love to find another Earth...

[palegray.net]

I'll add to my previous (admittedly malformed) post that I don't believe any reasonably advanced extra-terrestrial intelligence would exist in a biologically-based form; it's really a terribly inefficient means of maintaining an intelligent population. Carbon may have been the basis for life on this planet, but I assure you it won't be the last word in intelligence. What choices humanity makes with respect to convergence with something larger (i.e. more pervasive) remain to be seen, probably in the next decade or two. Don't get hit by a bus; things might just get kind of interesting.

Re:As much as I'd love to find another Earth...

[palegray.net]

Why anyone would think that an advanced machine intelligence would need to compete with human beings for resources is beyond me. After all, if you're essentially dealing with the mind of God on Earth, I'm fairly certain that such an entity would tend toward an exponentially increasing rate of efficiency per computing unit. This implies exponentially diminishing reliance upon external energy inputs. It also puts the human race in an interesting position: one has to wonder if this will be the tipping point where human beings are faced with a choice between merging with what's developing in order to preserve their own sentience, or face a standard-issue biological death. Kinda sounds like Revelation in a way, which doesn't bother me a bit. It actually amuses me that Biblical literalists could finally be proven wrong via the wonders of natural selection.

Re:As much as I'd love to find another Earth...

[Hognoxious]

This implies exponentially diminishing reliance upon external energy inputs.

Nonesense. Even if computational efficiency approaches infinity - which is pie in the sky anyway - other actions like moving around, extracting raw materials and producing useful things from them are still bound by the laws of thermodynamics.

P.S. exponential isn't a fancy word for "a lot".

Re:As much as I'd love to find another Earth...

[Farmer Tim]

Why anyone would think that an advanced machine intelligence would need to compete with human beings for resources is beyond me.

Me too, since I wrote nothing about competing for resources.

What I did suggest was that machines would prize precision and efficiency; by that measure we barely qualify as an intelligent species. Individuals may be precise and efficient, but as a group we aren't, and a single machine intelligence with many nodes looking for intelligence that resembles itself may not even realise that individual intelligent entities can even exist in co-operative societies. It may see us the way we see termites: mindless vermin that need to be eradicated before they spread and do damage (bearing in mind that such a machine would probably be so wildly different to anything we know that we may not even recognise it as a machine or intelligent. We might have been digging bits of it up for years thinking we're extracting convenient mineral deposits, not knowing the pest control fleet is already on its way).

Or it might detect our technology, come to the conclusion that we're a strange biological simbiote, and eliminate us in order to artificially advance the evolution of it's own kind. Then again, it might decide that we are intelligent but too wildly unpredictable to attempt to live beside, and simply destroy us as a preventative measure.

So there's carelessness and self-preservation to consider, and that doesn't allow for completely alien responses I can't imagine (and I'm sure a machine intelligence from another planet would have a few of those). Then you get to resources, and I could imagine that if Earth is the most convenient source of something, the termite-monkey things living here aren't going to be considered competition.

I'm fairly certain that such an entity would tend toward an exponentially increasing rate of efficiency per computing unit. This implies exponentially diminishing reliance upon external energy inputs.

Efficiency is finite, and even if it could increase exponentially indefinitely you're assuming that a machine intelligence wouldn't want to expand at a greater rate. Besides that, you can't build physical objects without matter, and even if a machine intelligence had a way of communicating instantaneously over interstellar distances, large local processing clusters networked together would probably be the most efficient arrangement. So planets are still likely to be valuable as both a source of raw materials and real estate.

There's no reason to assume a machine intelligence is benign simply because its a machine. Our machines are, but they're not super-intelligent intergalactic computing clusters striving for survival, so an assumption about one based on the other is almost certain to be incorrect. As for machines being less distressing, having seen people freak out at Windows desktops I'm inclined to think that bug-eyed monsters would seem more "human" because of their imperfections. Either way, an extra-terrestrial intelligence of any kind would shake a lot of people's fundamental beliefs.

Re:As much as I'd love to find another Earth...

[Patch86]

Maybe they've already made the jump to a pervasive machine intelligence...

They've had Conficker-gate too?

Re:As much as I'd love to find another Earth...

[Anonymous Coward]

The more we learn about what intelligence actually is about, the more we discover we don't have a bloody clue about it. Folks have been predicting that machine intelligence is "just around the corner" for nearly 40 years with a several million times increase in both processor speed and memory capacity since then. And we aren't any closer to genuine machine intelligence.

Anybody who spouts off that machine intelligence is something other than a science fiction story plot device deserves to have their head checked. I certainly don't see that as something inevitable, even though there are some cool tricks and "toys" that come from performing artificial intelligence research.

If there is a genuine machine intelligence that somehow emerges that can interact with a human on some level would also be a product of its heritage of being a "child" of mankind and would likely have the same wants, needs, and desires. But that is speculation at best, and I certainly can't say what millions of years into the future will bring... and for the most part I don't care. Neither I nor anybody that I know of, from the most "famous" to the most mundane will even be remembered or thought about that long from now. Heck, I'd be impressed if even popular movies, books, and music of today survive even a century from now... even assuming mankind doesn't enter into a global war suicide pact.

Re:As much as I'd love to find another Earth...

[palegray.net]

Computational efficiency approaching infinity is pie in the sky only as long as humans have a hand in controlling the process.

As for your notes on the work "exponential," wow, you don't say. You must some kind of college degree or something.

Re:As much as I'd love to find another Earth...

[iminplaya]

What you describe can only lead to.... Let's send the machines to find another planet while we kick back and smell the flowers...and have another...

Re:As much as I'd love to find another Earth...

[Haoie]

That's fine.

Our germs will take care of them, ha.

Or computer viruses created on a 1995 laptop. For sure.

Re:As much as I'd love to find another Earth...

[CmdrGravy]

What I did suggest was that machines would prize precision and efficiency; by that measure we barely qualify as an intelligent species

You've absolutley no idea what an alien machine might prize so deciding it would be precision and efficiency is an enourmous assumption. Even if it was true I've no idea how a species can be said to be precise, I think thats pretty much meaningless but as for efficiency I think any alien observer would conclude that humans are in fact very efficient in the way they interact and make use of their environment. If we didn't live efficiently we'd have become extinct a very very long time ago.

Re:As much as I'd love to find another Earth...

[Agripa]

Or maybe our technology took a different road.

Re:As much as I'd love to find another Earth...

[Farmer Tim]

I wouldn't rule that out, but it would have ruined the gag.

Interesting link, BTW. I'll have to check that one out.

Re:As much as I'd love to find another Earth...

[Farmer Tim]

You've absolutley no idea what an alien machine might prize so deciding it would be precision and efficiency is an enourmous assumption.

True. It was a suggestion made to set a scenario for a joke, and in order to create a scenario without any tangible information you have to make assumptions. Context is fascinating, isn't it?

Speaking of context, it appears you missed where I described other possible scenarios and wrote

...and that doesn't allow for completely alien responses I can't imagine (and I'm sure a machine intelligence from another planet would have a few of those).

I admit that I'm guessing, and that my guesses are from my limited perspective.

Even if it was true I've no idea how a species can be said to be precise, I think thats pretty much meaningless

Just like we have absolutely no idea what an alien machine might prize, we have no idea about its reasoning either. So by denying this as a possibility you're making an enormous assumption based on your limited perspective.

But is precision really meaningless? Some Earthly cultures put more value in precision than others...its hardly an accident that the vernier caliper was invented by an American engineer instead of a New Guinean subsistence farmer. Engineering is only one kind of precision, there are others if you apply some thought to the matter.

The fact is we are a pretty diverse bunch, and I'm inclined to believe that the cultural differences between humans and aliens would be much greater than humans and also humans. A cautionary tale of cultural difference: Australian aborigines have a tradition of shared property, and in the early days of European settlement this led to many being shot or imprisoned for stealing sheep. The concept of stealing was utterly alien and meaningless to the aborigines, the sheep were just standing around waiting to be eaten after all, and taking the odd one was no different to hunting 'roos, but this seemingly innocuous act carried severe consequences. "Of course", you say, "stealing is wrong"...the point is their culture didn't teach that, the closest they had to stealing was not sharing, so by their standards the Europeans were in the wrong. However, the matter was decided with firepower, which proves that not attempting to understand a concept that seems meaningless can be dangerous.

Now consider this: the word "aborigine" simply means "indigenous people". We, my friend, are the aborigines of Earth, and in all probability the technological and cultural gulf between us and a species capable of interstellar travel is likely to be much greater than Koori tribesmen and the Georgian English.

I think any alien observer would conclude that humans are in fact very efficient in the way they interact and make use of their environment.

Sorry, but you've again made exactly the same mistake you criticised me for by incorrectly assuming your idea of efficiency is universal. I'll take advantage of this to point out that logical consistency is another possible test of precision in a species ;)

Termites interact far more efficiently than humans (could a team of humans remove 90% of a building's structure without engineering knowledge, blueprints, or complex language and still leave it standing? Termites can). As for efficient use of the environment, I can point to a lot of industrial practices, ruined farmland, denuded forests and landfills that could look like unthinking vandalism and profligate waste to something that doesn't live here (and does look that way to a lot of things that do, if the green movement is any indication. As I said, your idea of efficiency isn't universal).

For example, we burn our immensely useful but finite supply of hydrocarbons for energy, yet we live on a planet with huge quantities of silicon and ample sunlight (a big WTF right there if you're a life form that eats electricity, as a machine intelligence well might). In the process of extracting those

I may be drunk...but

[Em Emalb]

How the heck do they know their "closer and closer"?

Someone not drunk (or less frunk) enlighten me.

Re:I may be drunk...but

[Quothz]

How the heck do they know their "closer and closer"?

Someone not drunk (or less frunk) enlighten me.

Your confusion over homonyms belies a good point. They don't know; they theorize that such things are out there and have built a craft to test this. The article (and summary) strike me as a bit optimistic about the inevitability.

Of course, research is sold to underwriters like business proposals. Funding would be hard to get if the researchers said "Geeze, I dunno. Earthlike planets? Mmmmayyybe. Let's go look! We'll need, eh, how about half a million - Dude! Hey! Hawking! Stop jonesing that telescope and pass it! - Half a million dollars? And I'll need to borrow your big Webb scope, yeah, the one Al Hale painted with the psychedelic shrooms."

Re:I may be drunk...but

[Quothz]

built a craft to test this.

Gyah, what am I smoking? Of course I meant "devised a methodology to test this".

Re:I may be drunk...but

[Anonymous Coward]

It's not Jonesing...it's Bogarting. Jonesing is when you really want something; Bogarting is when someone is hoarding something.

Yup!

[Mysteerie]

All This Has Happened Before, All This Will Happen Again.

Clarification

[Jane Q. Public]

I mean a few to ten years to build the device; a few to ten years to operate it. That is still vastly better than hundreds.

Wrong Approach?

[vigmeister]

IANA Astronomer, but perhaps it may be prudent to start looking at the more obvious candidates in terms of how conducive they are to human habitation and evaluate them in terms of what it'll take to make that possible. If an alternate habitat for humans is a moderately serious concern, why bother looking at worlds whose characteristics are under heavy risk of changing by the time we get there? Have we even found a better candidate that one of Jupiter's moons or Mars?

Cheers!

Re:Wrong Approach?

[Nyeerrmm]

I don't think the idea is to find a new place for us to live. Obviously, our ability to take advantage of such a planet is incredibly limited.

Rather, its to understand what the possibilities for life outside our planet are. Putting it in simplest terms, its working to get experimental data for some of the coefficients in the Drake equation.

Re:Wrong Approach?

[Neon Aardvark]

As it stands, we're never ever going to get there.

For interstellar colonization you need either: 1. Artificial wombs and frozen sperm/eggs 2. Colossal generation ship (impractical and very depressing way to travel) 3. Cryogenic storage of humans 3. Self-reproducing sentient robots (humanity wouldn't be spread, but intelligent life would).

And the ability for humanity to spend ass loads of money on something which they certainly won't see a return on in their lifetimes.

Re:Wrong Approach?

[Etrai]

1. Artificial wombs and frozen sperm/eggs 2. Colossal generation ship (impractical and very depressing way to travel) 3. Cryogenic storage of humans 3. Self-reproducing sentient robots (humanity wouldn't be spread, but intelligent life would).

Well yes, either of those four could be needed. Unless, of course, we devise some sort of superluminal menas of travel. Such means could be (stable) worm holes or perhaps even, for the lack of a better description, warp drive. While not likly, it's not impossible.

Re:Wrong Approach?

[mozzis]

Near-lightspeed travel should be possible. It takes whopping amounts of energy, but the amount of energy needed to drive a nuclear aircraft carrier would have been nearly inconceivable 100 years ago.

Re:Wrong Approach?

[Anonymous Coward]

Yes. This is never going to work.

We should send out a spacecraft on a 10 year mission - To seek out new life and new civilisations, to boldly go where no-one has gone before.

Or something like that ...

Re:Wrong Approach?

[gurps_npc]

I call stupidity.

You left out the answers of:

4. Human lifespan expanded to over 1,000 years. Frankly, this is easier and more likely to do than #2 or #3.

5. Many many set of short hops. Alpha Centauri is 4 light years away. An antimatter powered ship can reach 0.1 C. It only takes 40 years to get there. That is one generation, not multiple ones.

6. FTL travel. Sorry, but no I don't fall for the "we don't know how to do it, so it must be impossible" stupidity that prevented people from trying things like travel faster than the speed of sound. Do you know many people smarter than you thought we could not reach the moon? Lose your arrogance and admit that you don't know everything about how the universe works.

Re:Wrong Approach?

[Neon Aardvark]

I'm afraid I call stupidity on you, sir.

0.1 C as a peak velocity does not equal 40 years travel time to go 4 light years. Can you figure out why?

Short hops would be a pretty stupid way to travel for the same reason.

Additionally, antimatter is not a feasible fuel source given the immense cost, and the output (getting momentum out of hard gammas), and the storage difficulties. I'd like a source that shows antimatter can be contained using less energy then can actually be extracted from it - it's not clear that even this is possible. Also, any slight deviation in containment causes a runaway loss of containment, and boom - no more spaceship.

Anti-matter catalyzed nuclear propulsion is different (maybe).

RE FTL - I never said I know everything. On balance, given what I do know, it's never going to happen.

Re:Wrong Approach?

[jambox]

That's not actually true is it? Given time dilation, if there was a definite target then you could get there in a few years, subjective.

Re:Wrong Approach?

[Neon Aardvark]

If you're traveling at a tiny fraction of c, time dilation is negligible.

The point is that traveling at a tiny fraction of c is probably the best we can hope for.

Re:Wrong Approach?

[jambox]

For the foreseeable future yes. But there's no fundamental barrier to a suitably protected craft doing a fair chunk of c and getting a dilation factor of 2, making a 20 light year distant system reachable in 10 years.

Re:Wrong Approach?

[Etrai]

Indeed, relativistic velocities are very much within our grasp, but at 0.999c it would still take insane amouts of time to get anywhere interesting (read other stars, preferably with planets, and then preferably earth-like planets). Hence the need for superluminal travel. This does not however mean that the craft itself traveling is moving faster than the speed of light, relatively speaking (as in the case of worm holes).

I need your clothes, your boots and your planet

[dangitman]

'We'll have to be really lucky to decipher an Earth-like planet's atmosphere during a transit event so that we can tell it is Earth-like,' said Kaltenegger.

Governer Kaltenegger continued.... "It is not until this time that we can begin the search for Sarah Connor."

Wow!

[Jane Q. Public]

Two huge issues in as many sentences.

There is no logical reason to assume similar development, barring further evidence. That could be a good or bad thing.

But your second sentence... wow! Where do you get off making an assumption like that? First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

Second, even if they did, how in the world do you conclude that would be "less distressing"?? One does not follow from the other.

Re:Wow!

[palegray.net]

First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

In my view, I have good reason to believe we're much closer to that than most people would like to accept. Many reasons, actually. It's probably a normal side effect of human vanity that we take comfort in our present position at the top of the intelligence curve, but I think it's an inescapable fact that future historians (in whatever form they might take) will describe humanity as a species that was destined to outdo itself. To me, what occurs after that will be the most interesting chapter in the history of the human race.

Re:Wow!

[Jurily]

Second, even if they did, how in the world do you conclude that would be "less distressing"?? One does not follow from the other.

Well, duh. If they have advanced AI, they probably have internet as well. Which means we can view alien porn while we're being wiped out.

Re:Wow!

[Anonymous Coward]

Well, duh. If they have advanced AI, they probably have internet as well. Which means we can view alien porn while we're being wiped out.

What are the odds that they'd have tentacles?

Re:Wow!

[bencoder]

First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

When you take into account the speed up of technology, and the way we are able to build off the previous generation of technology to help us with creating the new version, you might realise that we are probably not nearly as far out as you think(perhaps that should be "as you hope"). From the lowest estimates from the likes of Kurzweil at about 10-20 years to the highest estimates of slightly less optimistic thinkers at only about a hundred years, it is likely to come fairly soon.

Re:Wow!

[Jane Q. Public]

Sorry, but I am a software engineer who has followed the field of AI since childhood, and I have a great many reasons to disagree. The field of actual AI has gone almost nowhere in the last 30 years. Yes, machines have been made to SEEM more "intelligent" in many ways, but that is not the same thing at all.

If you are referring to anything like human-level intelligence, machines are just about as stupid as they were in the 1960s. More hardware and software (and therefore more sophistication) can fit in a smaller space today, making many devices "smarter" in certain ways... but the fundamental problems of AI have not been -- and show no signs of being -- cracked.

Re:Wow!

[Jane Q. Public]

Please pass on to me ONE major advance that has been made in the field of Artificial Intelligence in the past 30 years. Just one. I would be interested in knowing about it, because I have been following this field closely and so far I have not.

Re:Wow!

[palegray.net]

My level of experience seems to closely mirror yours, and I have to respectfully disagree again. I do need to clarify a point: I'm not making any claim that traditional AI approaches have made any great strides in replicating a humanistic artificial intelligence. My point is that as we continue to see systems that are made up of increasingly dense and interconnected computing units (whether in a single lab or on a global scale), we're coming close to the point where computing systems need virtually no human input to continue to advance in power. It's been years since any one engineer has really been able to hold all the details of CPU design in his/her head, and that trend is only increasing as we rely more and more on existing computing platforms to develop the next generation of systems. Sooner or later (and my wager is relatively soon), the need for human involvement will diminish to a nearly unappreciable level, which will probably cause a fair amount of upheaval in other economic areas.

I recognize that you're taking a more conservative approach than I am with respect to this matter, and I respect your point of view. I'm guess I'm taking the long view of the acceleration of information exchange on this planet over the two last thousand years or so, and trying to make somewhat educated guesses where it's all going. Thanks for your feedback!

Re:Wow!

[bencoder]

Please tell me ONE major advance in whatever field you work in.

It doesn't really work like that. Very rarely in science is there some major advance that you can specifically point to. Everything we had back then in AI we still have, but it is so much better. The neuroscience side of things is progressing, we are getting better data about the brain. Developing practical applications based on that. Voice recognition is pretty good now, automatic translation is better, computational vision is better, autonomous robots are better. And frankly, it's rather difficult to put theories on artificial intelligence when the computational capability isn't yet there, so things are getting better as computation gets faster.

What would satisfy you as a major advance in the field? The problem with AI techniques is that they very quickly leave the field of AI, or they don't yet have any practical applications. Juergen Schmidhuber's work on Recurrent Neural Nets is very impressive and he's a good name to watch for the future of AI.

Re:Wow!

[Jane Q. Public]

Yes, I think for all practical purposes we were discussing different things.

Re:Wow!

[Jane Q. Public]

Sure, they're all getting better. As I pointed out elsewhere, more hardware and more software can fit in a much smaller space today, allowing us the sheer computational power to make many devices much more sophisticated than they were before. And our techniques have improved, and so on. Incrementally.

In my opinion, voice recognition and language translation are irrelevancies. They make input and output somewhat easier, no more. I do not believe they are essential characteristics for intelligence.

And I can't give you one "major" advance in my field, since that field happens to be software, and except for certain problems in number theory, there have been no big breakthroughs of which I am aware.

And that in fact is my point. I do not believe we will achieve "Artificial Intelligence" with mere incremental changes. Throwing more hardware and software at it is (I maintain) not sufficient to achieve anything approaching what we normally call human intelligence. We will need a breakthrough of some kind... a paradigm shift, as it were. And so far, it hasn't happened.

Which in turn makes it impossible to predict, because breakthroughs are by nature unpredictable. Nevertheless, I do not believe it will be very soon.

Re:Wow!

[palegray.net]

By the way, would you have any ideas for improving my article on good development practices (see sig)? I'd appreciate any feedback you might be able to offer on it. Thanks!

Re:Wow!

[bencoder]

I guess it depends what you mean then. To me artificial intelligence doesn't necessarily have to be exactly the same type of intelligence as a human, that's practically impossible, because it would have to have all the same type of sensory data as a human, which means robotics, or at least human->machine interfacing, has to come along massively. But an intelligence capable of solving most of the same problems as humans can, within its own domain (whether that be an artificial 3D world or a world of numerical data), should be possible.

Of course, like you say(and I said), it's unpredictable, so I guess it comes down to optimism on my part(and trends in computation) that says it will be possible soon.

Re:Wow!

[Jane Q. Public]

I will leave a comment or two on the page.

Space race across the divide

[DigiShaman]

Let's just assume for a moment that a 2nd Earth was discovered with life an all. Would this be a turning point for actually dropping vast amounts of money in R&D for interstellar travel? Iâ(TM)m talking about developing some really exotic technologies ranging from point-to-point FTL travel to wormhole-like jump drives.

If the laws of physics permits, such a discovery might be what provides the justification for investors and government agencies alike.

Re:Space race across the divide

[Nyeerrmm]

I think if someone had a solid path to go down for developing FTL travel they would have no trouble finding funding. In fact I think that would have the effect of encouraging more missions like Kepler, so we would have good places to go once we got it working.

I'd venture a guess (I'm not involved in anything similar to that kind of physics) that the kind of results that would lead to a radical new form of propulsion wouldn't come from a heavy focus of funding, but rather continued support of seemingly impractical physics research in many or all directions.

Heavily directed funding is great for improving the efficiency, reliability and capabilities of current ideas, but can't really lead to the kind of radical breakthroughs FTL would require. A nice succinct quote from the West Wing TV show: "If it was up to the NIH to cure polio through a centrally directed program, you'd have the best iron lung in the world but not a polio vaccine."

Re:Space race across the divide

[ionix5891]

yaha another planet to poop on ...

Re:Space race across the divide

[grumbel]

All the money in the world doesn't allow you to break the laws of physics. And even if you can construct a theoretical possibility of FTL, you will likely have a really hard time implementing it, i.e. for a wormhole you might need two black holes, which aren't exactly easy to come by and then you have to find a way to survive traveling through that thing and all that stuff. So not likely to happen. Much more likely that the Kurzweil's singularity will happen, we will all turn into a cyboard super race and then no longer need FTL, because we can all put our brains on sleep for a few hundred or thousand years. Another alternative would be to simply construct interstellar travel with our current day technology, which isn't all that bad, you can reach the next star in around 100 years.

Re:Space race across the divide

[Anonymous Coward]

only if it yields results before the next elections.

Re:Space race across the divide

[PaganRitual]

In hindsight this entire post is me digressing, but I'm honestly not convinced. The general direction that the progress of the world is taking is one of the people in control locking down and controlling society so to advance their own personal gains as much as possible for the short time they are alive and/or in power. Knowledge of life on other planets and R&D on how to get there, doesn't make money, it only costs money. If possible, I imagine information like this would be censored as much as much as it could be. It also doesn't provide results in the 5 minute turn around of most political party periods of power, and in the eyes of the "make it happen yesterday" moronic populace.

And this is even before considering the incredible vested interest in keeping this sort of info under wraps that the worlds religions would have. And that people in general would likely freak out at the realisation that they actually aren't that special in the universe and that a life spent attempting to distract themselves from their inevitable death isn't one well spent.

I would have been much more postive about this whole thing had I not been suffering an incredibly bad case of (reflux and) Mondayitis. But seriously, general society is moving horrifically quickly in the direction of self absortion and me-me-me mentality that the idea of spending money on discovering other worlds isn't of interest to them.

That's of course well before we consider the "we shouldn't go to other planets before we fix up this one" idiots.

I used to be incredibly excited about Astronomy and the Universe as a whole and the possibilities that were out there. Now it seems safer to just never look because the only thing worse than never knowing whats out there is discovering for sure that there is something amazing and finding that no one will let you go.

(+5, Cynical Git)

worthwhile spending.

[timmarhy]

hopfully we spend more money on such scientific endevours from now on rather than blowing up the middle east or trying to convert the unwilling to democracy.

it's ironic but i really think oil wasn't the reason for invading iraq - it would have been cheaper to just BUY their oil.

Kepler is not going to visit these planets

[postmortem]

OP misses to say this spacecraft will rotate around sun and listen to the stars. That's it, no special quest.

Important distinction:

[RyanFenton]

There's an important distinction between it being hard to find an earthlike planet, and there not being an earthlike planet to find at all.

Our mechanisms for finding planets are all in wobbles in the wavelengths from the light of stars. And because of that, we tend to only see the big wobbles, because small wobbles tend to get lost in the noise.

It would be nice if we could shine a flashlight and get a real look out there, but in most cases, we'd never see what we shone light upon in our lifetimes.

The universe is a HUGE freakin place, filled mostly with stuff we can't get a good clear look at yet.

Entire worlds like ours are are both all we know, but at the same time, are too small for us to even notice in the grandness just outside our atmospheric window.

Ryan Fenton

Simple explanation

[Farmer Tim]

Second, even if they did, how in the world do you conclude that would be "less distressing"??

This is Slashdot, and you're wondering how someone decided that a machine would be easier to deal with than a living creature. Hmm...

Re:Simple explanation

[palegray.net]

You probably meant your reply in jest (understandably so, considering the stigma of underdeveloped social skills that Slashdotters are famously afflicted with), but I'll reply anyhow :).

I love people. I'm what you might call a highly social nerd, someone who really enjoys the company of others in a variety of social contexts. Yeah, I also enjoy sequestering myself in my home office and writing code for a couple of days at a time, but there comes a point where human contact is critical for me. I have friends from a diverse range of backgrounds (Naval service is good for exposing you to a wide range of personality types from different parts of the country); I guess I kind of enjoy being a part of different cultures and mindsets.

I feel like I'm walking a strange bridge sometimes, though... I do have friends who aren't exactly, ummm.... social in nature. I also have friends who wouldn't know a terminal window if they got hit by a picture of one plastered to the front grill of a dump truck. Still, I like who I am, and I enjoy the life I live. I wish the same for anyone who can pull it off :).

Re:Simple explanation

[Farmer Tim]

I did indeed mean it in jest. And to be honest, most of the nerds I know have more diverse social lives than the non-nerds, though their activities may not be the popular idea of fun. That just makes them more interesting to be around, IMO.

Re:Simple explanation

[palegray.net]

Well said :). Thanks for your other response, too; it was a good read.

Twin Earth

[BorgCopyeditor]

Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere?

Also, will they mean the same thing by "water," even if their oceans are filled with XYZ?

</putnam>

Re:Twin Earth

[DamienRBlack]

Haha, I was laughing about finding a "twin earth" too. I don't think anyone else gets the joke.

NASA needs to latch onto this.

[saiha]

Finding a "twin" earth, no matter the distance (assuming if we can see it, we can get to it at some point in the future) is possible _the_ most important thing for the continuation of the human race.

As for being harder than "we" thought, to me at least (IANAA) it seems pretty damn hard to me. Even if we find a planet that could have human life, would it have life on it? Would that life be toxic to us? etc...

Re:NASA needs to latch onto this.

[Anonymous Coward]

You obviously don't understand the distances involved.

Re:NASA needs to latch onto this.

[saiha]

We don't have the technology for any type of hibernation space travel now, which is why I think its so important to follow these types of research. Even if it takes 100000 years to travel to a new planet, that's pittance compared to what it took for current level sentient life to develop on Earth.

Re:NASA needs to latch onto this.

[Anonymous Coward]

While FTL travel would be a very big step for us, it'd likely be easier to just try to terraform Mars and maybe one of Jupiter's moons rather than setting our sights on things 20 light years away.

If we started now, given the exponential rate of technology growth, we could probably have cities on Mars within a couple hundred years, and not even the domed variety.

Re:NASA needs to latch onto this.

[Hognoxious]

A "twin" earth finding us, no matter the distance (assuming if they can see us they can get to us at some point in the future) is possibly _the_ most important thing for the continuation of whatever intelligent species lives there.

FTFY.

Re:NASA needs to latch onto this.

[nscott89]

The chances that the life on another planet could possibly affect us, unless we are talking about animals, is VERY low. Bacteria, protozoans, and viruses on earth have, essentially, targeted us and evolved to be more efficient killers. The chances that alien microorganisms could have developed characteristics that would be harmful to us is pretty low.

Re:NASA needs to latch onto this.

[grumbel]

I have some doubt about terraforming. With genetic engineering getting more and more common and computers getting faster all the time, I think its much more likely that we simply transform the human race itself to be suitable for life on other planets then transforming the planets themselves. Quite a bit cheaper to engineer a few cyborg colonist then to put a breathable atmosphere on Mars, after all we already kind of done the former, the rovers just need to get a little more clever.

Re:NASA needs to latch onto this.

[Ralph Spoilsport]

Finding a "twin" earth, no matter the distance (assuming if we can see it, we can get to it at some point in the future) is possible _the_ most important thing for the continuation of the human race.

No it isn't. Humans are built for here. We are an evolving species and once the oil is gone and the metals we've dug up oxidise and wash into the oceans, we'll be right back to our neolithic lifestyle - you know - the one that worked for hundreds of thousands of years.

Industrialism will disappear and we we relocalise and eventually evolve into something else. If we prize certain features, such as intelligence and co-operation, to deal with changes in our environment, we might become a "better" species. If we prize violence and competition, then we will become something else. Likely, it will be a bit of both.

The stars will still be there, but they are not for us.

Wrong planet.

RS

Re:NASA needs to latch onto this.

[Anonymous Coward]

Do you think we can build a machine which will operate for 100,000 years?

Re:NASA needs to latch onto this.

[Fluffeh]

possible _the_ most important thing for the continuation of the human race

Wow, and here I was thinking it would be something much simpler: Like us learning how to manage our own planet and resources properly.

Re:NASA needs to latch onto this.

[saiha]

If we had 0 population growth that probably would be simpler. But IANAE.

Time difference

[istartedi]

Of course, it will only be possible to tell if it was Earth-like X number of years ago. Since there are only a few stars within 100 light years, X will usually be more than 100. In the meantime, there could have been a planet killing asteroid, or an advanced civilization could have nuked itself. So, we can only really find "twin Earths" from the past. We'll never actually know what it's like until we go there...

...actually, even that's not true, in the sense that "we" means everybody on Earth. Only the travelers will know it's true. Earthlings will have to wait for the return trip or signal, to tell them that it *was* true. Even then, for most stars it would be your great-great-great.... children receiving the signal.

Bottom line? The Universe's speed limit sucks. Where's the fuzzbuster?

Re:Time difference

[Anonymous Coward]

People repeating this nonsense is getting old. Yes, the fact that it's 200 lightyears away means we're seeing the planet as it was 200 years ago. But come on, use your fucking brain. 200 years on a geological scale is NOTHING. So yes, knowing what the planet was "like" 200 years ago will still give us a very relevant picture of what the planet is today.

And more generally, unless we're talking about objects outside our galaxy, the travel time of light can be safely ignored for most purposes.

Re:Time difference

[angel'o'sphere]

In the range of 20lyrs there are about 100 stars, in the range of 250lyrs about 260000.

See: http://www.atlasoftheuniverse.com/

angel'o'sphere

Re:Time difference

[Anonymous Coward]

One would think that we'd have checked the nearest stars first. They're easier to observe.

Re:Time difference

[Tablizer]

Bottom line? The Universe's speed limit sucks.

Who knows, it may be saving our asses from giant brain-sucking squids from Voltar. In other words, maybe the Anthropic Principle has made space-travel difficult "on purpose".
         

Re:Time difference

[DamienRBlack]

If giant brain-sucking squids from Voltar are intelligent, then the anthropic principle can't really be used to explain why they aren't "allowed" to attack us, can it? Or are you narrowing the anthropic principle to human life, not just intelligent life? I suppose that might be valid.

The smallest has just 3 times Earth's mass!

[G3ckoG33k]

The smallest, MOA-2007-BLG-192L, has just 3.3 times Earth's mass!

That is good new for us twinks! I don't have the muscle mass to suddenly weigh 260 kg. My 78 kg combined with my height makes me a twink)

It may take two or three generations to get used to that, i.e. you need to have been born by a mother who herself had been born there. My underlying idea is how one's body growth increases if you are born by a well fed mother. This is readily exemplified in western Europe with the introduction of the potato. The average height increased by more than 100 mm in 150 years.

That is not an example of evolution, however. It just shows how important nutrition is.

Re:The smallest has just 3 times Earth's mass!

[zombie_monkey]

I don't have the muscle mass to suddenly weigh 260 kg.

Assuming an equal density to that of Earth, the surface gravity would not be 3.3 g. It would be 3.3^(2/3) g, or approximately 1.5 g.

Re:The smallest has just 3 times Earth's mass!

[zombie_monkey]

Dammit, I'm still half asleep. That's 3.3^(1/3) g, which is 1.5 g. And is still the correct value.

Re:The smallest has just 3 times Earth's mass!

[deglr6328]

uhhhhh are you sure you know what a twink is, cuz.....

Obviously not

[anza]

Submitter obviously forgot to DVR the last episode of BSG.

Just call it an M-class planet already

[Nebulious]

We're all familiar with the term already.

We'll find one eventually

[TFer_Atvar]

After all, Battlestar Galactica did it.

Re:We'll find one eventually

[Anonymous Coward]

All this has happened before and will happen again. EOL

Re:We'll find one eventually

[Anonymous Coward]

But the Cylons of the 13th colony destroyed it. Of course it's been 150.000 years, that earth could become habitable again :)

Little green men?

[PolygamousRanchKid]

... the little green men...

Back in the 1960's Captain Kirk couldn't swing a dead cat around his head without hitting a "Class 'M'" planet every week. Can't NASA lure him back out of retirement?

. . . and his little green men were always platinum blond chicks: http://en.wikipedia.org/wiki/File:STGameTrisk.jpg

I nominate "Shahna" as the official Slashdot mascot, because she is wears a tinfoil bikini . . . and she wields a giant can-opener.

Now, where is my "rogue" source code? Does a giant can-opener do more damage than a two-handed sword?

Re:Little green men?

[Farmer Tim]

. . . and his little green men were always platinum blond chicks

Maybe not men*, but some were definitely green.

*At least that we know of. I always had questions about why the young, naive Chekov was the navigator...

And then what? invade it?

[master_p]

Dump all the excessive population of this planet to the new one?

Maybe send the Chinese there? :-)

I hope the planets we find don't have gold or oil though...

Re:And then what? invade it?

[troll8901]

Not to worry. After dumping other people there, you can use their land to build "nucular" plants.

But be careful, the Chinese are coming up hard and fast on their space rocket technology. Who knows, we might be the ones being exported there, and our lands used for nuclear plants.

Re:And then what? invade it?

[Anonymous Coward]

At this rate, the Chinese will probably send you there :) In Soviet Earth..

Re:And then what? invade it?

[dkleinsc]

Yes, we'll put all the middle managers and telephone sanitizers into a big B Ark ship. To save them from the giant mutant space goat.

Easy to find...

[Anonymous Coward]

I see the dead pigs out on the highway / not enough to feed my soul. / You had your chance now you do it my way / all badges go down that hole. / I'm alone in the buckets of a mach one / and down inside I know you love me too. / So have a beer with Christ or Hoover / Twin Earth's coming down on you.

It's on the album Superjudge.

LOL

[G3ckoG33k]

LOL! ****, you're right. I didn't... I looked it up. I had thought it was for skinny persons in general... Oh my! ****!

Re:LOL

[bpsbr_ernie]

Now of course, if that is not the type of twink you are/want to be... there is also...

http://www.wowwiki.com/Twink

Twinks are player characters who have gained the best powerful gear for their level with enhancements such as expensive weapon enchants, leg patches and BoE/BoP greens, blues or epics. Twinks are mainly used in PvP fighting and Battlegrounds. Twinks obtain their items through rare drops, drops off of bosses in instances, rewards from quests that are difficult to complete at their level, and from the Auction House.

Either way, I guess a twink is a twink... A twink is "memorable for his outer packaging", not his "inner depth".

I for one

[Joebert]

... am looking forward to welcoming our new "Flip That Planet" overlords.

Life...

[nscott89]

According to theories of what the earth's atmosphere was like before life flourished, the atmosphere was full of CO2 and nitrogen. There was no oxygen. According to our understanding of the earth 4 billion yrs ago, the earth would be a VERY different place today if there were no life here because oxygen is a byproduct of photosynthetic life. I theorize that the moment we find a planet like ours, we will have found life on another planet.

Twin Earths?

[flajann]

I am always annoyed with the popular press phrases things like this. If we find an Earth-like planet orbiting some distant star somewhere, it will not be Earth's "twin". It will be a planet similar in some respects to Earth. Similar in some respects; different in others. There is no "twin" relationship, and the intelligent inhabitants of that planet, if any, may be rather annoyed by our arrogance.

Speaking of intelligence inhabitants, it would be wonderful if we could detect such, but very unlikely, unless those inhabitants also happens to be at a technological development similar to ours, where they are leaking radio signals all over the place. Good candidates for SETI to focus its search. Maybe even the SETI@HOME crowd can put actuators on that satellite dishes to focus on said planet...

The real killer here is that even if we did find a so-called "twin Earth", we wouldn't be able to do a whole lot about it. Sending a probe there would take thousands of years. Maybe we could do a massive interferometer in space to study the planet in more detail. Forget the manned mission fantasy so many have. We have yet to put a man out past the orbit of the Moon and we're going to travel to a distant star many light-years from Earth?

The physics of Interstellar Travel is daunting, to put it mildly. When I was a kid diddling around with the Special Relativity equations, I was all elated until I realized the ENERGY required to make time dilation a useful thing -- for the travelers, anyway -- is way beyond anything we humans are likely to be able to do now and in the future -- if ever. And all those dreams I had as a young boy of going to the stars died.

Later, I got into the whole Wormhole stuff, and read some of the stuff Kip Throne and others wrote, and got depressed again. Wormholes -- if they even exist -- is far more daunting in terms of energy requirement than even lightspeed travel, by many, many orders of magnitude!!!!!!

Well, wonderful if we can find. But then we'll be more frustrated when we all have to face the realities of physics. Science Fiction lost a lot of its appeal for me because most of it turned out to be simple fantasy, impossible to achieve. My ignorance as a kid is gone.

Meanwhile, we have made tremendous strides in Science and Technology since my teen years, the stuff of Science Fiction 30 years ago. We do live in a marvelous age. It's just that Interstellar Travel will not be a part of it. :-(

Bullets vs. Energy beams

[firmamentalfalcon]

Bullets hurt people because of human blood circulation (loss of blood) and the size of our organs (heh). If robots were built differently or little green men evolved differently, bullets would most likely be ineffective. There is no reason that there is only one wire connecting processor to leg and opening one loop should not hurt the other parts of the circuit. Also, there is almost no reason why the processor needs to be 15 cm big, or the leg motor has to take up the whole length of the leg. There is also no reason why the robots or green guys have to be human size.

However, as long as they are still made of molecules, high amounts of energy should still be able to separate the molecules that they are composed of, and hopefully eliminate them.

Re:Bullets vs. Energy beams

[xpuppykickerx]

Kill the head and the body will die.

Re:Bullets vs. Energy beams

[Farmer Tim]

Well, that plan fails if the number of heads doesn't equal one.

What complete disintegration lacks in finesse, it makes up for in certainty.

We are in a sea of limited thinking...

[bradbury]

The question to ask is not weather there are "Earth" like planets out there. The work by Lineweaver's group already suggests that they are there (simply from a proability basis). The question to ask is where they are relative to our state of development? And if one truly understands computer science, and life science, and nanotechnology, then they are out there, they are developed (much further along than we currently are) and they have most probably have evolved into a Matrioshka Brain architecture. Which leaves us in a sea of picturing planets like our own instead of realizing that solar systems are engineering zones. And FYI, detecting Matrioshka Brains will not be done by the Kepler telescope, it might be done by the JWST, but only if the powers that be decide to survery a large enough area of sky.

Re:We are in a sea of limited thinking...

[justinlee37]

The work by Lineweaver's group already suggests that they are there (simply from a proability basis). The question to ask is where they are relative to our state of development?

There is little point in asking a question we can't yet answer. Finding one is a necessary precursor to answering that question.

And if one truly understands computer science, and life science, and nanotechnology, then they are out there, they are developed (much further along than we currently are) and they have most probably have evolved into a Matrioshka Brain architecture.

You seem pretty sure of yourself that anyone who "understands" simply must conclude that there must be other Earth-like planets with life as we know it and it must be more developed than us. Didn't all of that science and the scientific method teach you to be a little more conservative in your assumptions, Bradbury?

Re:We are in a sea of limited thinking...

[bradbury]

Worthwhile question. Are we the members of an exclusive club or are we the members of a somewhat more global club?

And the current answer is that we just do not know. The answer is interesting either way. But we have to determine which way it goes.

I am voting on the "more global club" basis simply based on the odds of development and when they took place. But I could be very wrong.

R.

If you find an earth like planet....

[voss]

with no intelligent life within 100 light years of earth

1) FTL travel would have a purpose not just a science fiction wank-off
2) People with lots of money can tell the collected governments of the world to go take a flying leap, that alone would be worth billions to right people
3) maybe all those people saying "we need a homeland" well there you go.

Just ask the Andromedens!!

[cagrin]

They would know...;)

http://www.youtube.com/watch?v=PWvW3T84SiU

P.S.
http://www.youtube.com/user/cagrin10 (playlists of many videos i've watched over last year about government/banking/etc)

No Princess Lea ... no twin-earth

[noshellswill]

... no byte-boyz fantasy worlds. It's only us alive, palsy. Only we are aware ... of the nothingness that surrounds. The entire rest of the universe is dead cold rock. Surrounded by dead cold gas. Surrounded by a dead cold vacuum of whatever ilk. Have a nice day.

Re: No Princess Lea ... no twin-earth

[ColdWetDog]

... no byte-boyz fantasy worlds. It's only us alive, palsy. Only we are aware ... of the nothingness that surrounds. The entire rest of the universe is dead cold rock. Surrounded by dead cold gas. Surrounded by a dead cold vacuum of whatever ilk. Have a nice day.

Better living through Chemistry.

You'll feel better if you stay on your meds.

you won't find it

[Anonymous Coward]

They're getting "closer" to finding such a planet? How do they know they're getting "closer"? Is someone saying, "warmer" and "colder" for them? That statement is complete nonsense.

I'll explain why you will not find an Earth-like planet anywhere: First, look at the situation we have here on Earth. The planet is a certain size and weight. The sun is a certain size and weight and produces a certain amount of heat and light output. The Earth orbits the sun at a certain distance, which varies throughout the year and from year to year, in such a way that if you graph the distance from the sun over time, it would appear as a wave with a quarterly annual frequency riding on a wave with a frequency several decades long, riding on a wave hundreds of years long. This produces climate change and is the cause of the several ice ages and warmer periods this planet has experienced. There is a certain average distance from the sun, as well as minimum and maximum distances and the frequencies discussed. The Earth rotates on its axis at such an angle and "wobbles" at such a frequency that you have the changes in season. The moon is a certain size and weight and orbits the Earth in such a way that produces several effects. First, from the ground, it appears to be the same size as the sun. Secondly, it orbits at a speed that causes the effect of changing phases of the moon. If you pay attention to the moon when only a portion of it is visible, you will see that the effect is produced by the fact that one hemisphere of the moon is lit up by the sun and the other is dark. When the moon comes out in the evening, you will notice that it is moving at such a speed that it either "chases" or "runs away from" the sun, such that its phase does not change throughout the night. The moon has several very important effects on the planet, causing such things as the changing tides. ALL of the above contributes to having life-supporting conditions here. If any element were missing or off, life on this planet would NOT exist, and we haven't discussed the composition of the atmosphere yet, the layout of the planet, the fresh and salt waters, the layout of the continents, the presence of plant, animal, and human life here, and a zillion other things.

I'm sorry, but you will not find another planet that supports life in a comfortable manner. You might be able to put humans on some planet where they'll have to live in enclosed domes and where their bodies will be adversely affected by being too heavy or too light. But you won't find another planet close enough to the design of the Earth to provide the sort of existence we here take for granted.

Re:you won't find it

[oftenwrongsoong]

Mod parent up. This is a very good description of the issues affecting the possibility of locating a twin Earth. I, too, believe that you won't find a planet to match the conditions here on Earth. Maybe you can find something with a similar gravity and a similar atmosphere, so you'll be able to walk around on it without wearing a space uniform and your body won't get all messed up from being too light or too heavy. But then again, I doubt you'll have a similar enough climate. Or 24-hour days. Or the right temperature. In short, there are so many issues that you need to take into consideration. I know someone will find fault with what I'm about to say, but the general order of things here on Earth suggests that the whole system was created by God to operate in this manner. There are just too many variables, where any one of them being off by 1% would screw up the whole system, that you can't just write it off as being pure luck. And the parent is totally right about the moon, now that I think of it. If it didn't "chase" the sun at just the right speed, and if the Earth didn't spin at the right speed, then the phase of the moon would change throughout the night, and we as a civilization would have no concept of a calendar, except to the extent that we have the concept of the day and the repeating cycle of seasons.

Aren't we missing another possibilty

[Glasswire]

Is the goal really to find "earth-like" planets (ones are similar, size, dist from star etc) or to find "habitable" planets which could support life somewhat like us or (maybe someday) us.
These planets could very well exist at different distances as moons of gas giants that are closer to the star than our gas giants (which might provide supplimentry heat) and while these would probably be smaller, many gg moons are not much smaller than earth. Needless to say, these are going to be really hard to pick out from here, so in one sense, right now, we're looking for what we possibly can see, even if it's not all of what we're interested in.
I am not an astronomer, obviously, but it there any merit in this?

Re:Aren't we missing another possibilty

[oftenwrongsoong]

I am not an astronomer, obviously, but it there any merit in this?

Yes, it has merit. That is, it has merit if you're the one who somehow convinced the government (or other rich organization) to give you millions of dollars in research grants. You get a nice house, a nice car, send your kids to a nice private school, take a glance at the sky, and tell us that you're getting closer by the day to finding a twin planet. :-)

Re:Solution:not hard at all

[ssintercept]

Last call: Show tonight at the Red & the Black
Once last pleasant reminder. We're playing tonight at the Red & the Black and home you DC folks and make it out for an early kick off to the Memorial Day weekend.

Twin Earth
w/Scribes of Fire (Brooklyn grunge / prog / metal)
The Prisoner's Dilemma (DC indie instrumental)
Thursday, May 22
The Red and the Black
1212 H Street, NE
Washington DC
9 p.m.

$8

Television lied to me :(

[Anonymous Coward]

AGAIN!

Sun as a gravitational lens

[Katatsumuri]

This paper from 1979 suggests that we could use our star for a lens:

http://www.sciencemag.org/cgi/content/abstract/205/4411/1133

It requires a dedicated telescope at 500 AU for each observed target, so we definitely need good pre-screened candidates. On a bright side, we might see them in some detail in less than 200-300 years.

Columbus Effect

[DG]

In the near term, certainly.

But imagine discovering a 1G +/- .2G planet, temp range -35C-40C, 75%N 25%O. Doesn't matter how far away; imagine finding one.

I'd bet we'd start spooling up our manned spaceflight capability pretty darned quickly after that, and actual money would start being spent on solving the distance problem (propulsion techniques, suspended animation, longevity, generation ships...)

When all that is "out west" is the edge of the earth, why bother? But as soon as the New World is discovered, all of a sudden the rewards outweigh the risks.

If Venus was inhabitable, we'd've had routine interplanetary spaceflight 20 years ago. Manned spaceflight has gone nowhere because there is no decent place to go.

DG

See, there you go

[Jane Q. Public]

already proposing theoretical limits, that in fact are not so. This is exactly to what I was referring.

If there are limits to the tech of certain ways to find out things, we will just change the tech... or find a different way.

For example: one well-known way to overcome the limits of mirror size is to use multiple mirrors, spaced a good distance apart. We already use this technique in other areas of astronomy. It allows better resolution than the sum of the individual mirrors would indicate... almost like multiplying it.

But that is just one though off the top of my head. I am quite certain that if we get an inkling that a few planets might be earthlike, we will soon find a better way to tell for sure.

Re:See, there you go

[Nyeerrmm]

Using multiple mirrors is great for increasing your angular resolution, I know, its what my graduate thesis is about. Unfortunately, it's not nearly as good at increasing your light gathering capability. 6.5 meters is the size of the JWST, so if you wanted to improve your SNR by a factor of 10, you'd have to have 10 JWST's, and funding that is just not going to happen at this point, not without a drastic drop in cost of access to space.

The gravitational lensing concept that others suggested is valuable because it is actually collecting more photons, thus allowing you to detect smaller variations in the light with the same sized mirror. Without that, more aperture is the only way to go, and it has to be aperture area: sparse apertures with long baselines can only help if you're trying to resolve the planet directly, and from what I can tell, the photon flux from the planet directly is going to be so small it wouldn't give you anything.

Re:See, there you go

[Jane Q. Public]

I understand. But what I am trying to point out is that everybody is describing these limits in regard to today's technology. Now, that is not unreasonable, since tomorrow's technology is largely un-guessable. So while my belief might come down to something approaching "faith", I still believe that in 10 or 20 years we will have technology to make this determination in less than 2 or 3 hundred years. After all, the idea that we would even be detecting earth-sized planets was beyond the practical technology of 20 years ago.

Re:See, there you go

[Nyeerrmm]

Yes, its possible, but the way it will be possible is through drastic reduction in launch costs that can get you far more aperture or the ability to get a JWST sized scope out to a 500 AU orbit for gravitational lensing. I have a lot of hope for that, I'm involved with organizations working to make it happen.

However, there really is no way to develop a new instrument capable of doing so without incredible infrastructure or discovering a brand new kind of physics that allows it. The developments of the past 20 years that make this possible are predictable, understandable, and linear. Adaptive optics is a natural development given increased computer processing, higher-sensitivity sensors are an easy assumption to make, and space telescopes have been posited for a long time. The real surprise was how many planets there were out there. Predicting what we can do now 20 or 30 years ago is more like predicting the pervasiveness of the internet... unknown to most people, but there for those in the know to see.

Unfortunately, while larger apertures in space are a given, that can only give you a reasonable expectation of 2-3 times the sensitivity. Sensor sensitivity is approaching its limit. Getting past the limits the paper lists isn't a matter of being particularly clever with current technology or predictable development, its on the same level as developing FTL travel. While I certainly believe and hope we'll find ways to do it eventually, its completely beyond the realm of practical engineering, and beyond what we can say "the next mission" will be.

And yes, I understand your point about we'll discover a better way to do it before we could get reasonable data this way, and I agree. However, its going to be expensive, and its unlikely we'll have the political will to get it going in the near future.

But, see...

[Jane Q. Public]

even you are stating limits in terms of TODAY. Today's tech might limit our ability to discern earthlike planets to 2 or 3 hundred years... but in 20 years, will our technology still be so limited? You are second-guessing the future in a way that history suggests is incorrect.

Not much more than 20 years ago, the very idea of trying to find earthlike planets telescopically would likely have been laughed at.

I'll give you a hint ...

[ezzthetic]

There's one on the far side of our sun.

It's exactly the same as our world, except everything is a mirror image.

just wait

[cavebison]

Not sure why we bother looking so hard.
Just wait till the Twelve Tribes get here... not long now!

Best case consequences

[Anonymous Coward]

Finding one would mean war (finding places on our own planet has never proven otherwise)

Re:Best case consequences

[Feminist-Mom]

True. But now we are a little more experienced (I hope) about this. And we might not start a war with them if they had FTL drives. We'd just have to hope that "How to Serve Man" was not standard reading in their elementary schools.

why???

[ddraculdiablo]

Why are we only looking for earth sized planets? Is is some rule that a planet can not be the size of lets say jupiter and still be solid, contain an atmosphere,harbor life. It's far easier to spot these planets because of the wobble effect. The way it looks to me is that we are only focused on finding planets that are the same size as us and have a similer sun as us. What if an earth like planet is revolving around a red supergiant (for example) and is 3x farther away from it's sun then we are but it's the right distence to form life. When dealing with Space and alien life we have to take in effect things like there could be life on a gas planet too.

Missing question

[Mr. Firewall]

the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere?

Does it have Global Warming?

The idea of Earth like planets is flawed.

[bradbury]

The concept is based in the perspective of a 100,000 to 3,000 year human time scale perspective, which from astronomical time scales is very very small. Since the time scale from the development of human level civilizations, to transhuman levels of civilizations (with complete nanotechnology capabilities which can easily disassemble Earth like planets (or entire solar systems) appears to be on the order of a few thousand years -- you have to make an argument that development is somehow constrained. Because if the majority of civilizations in our galaxy are older than ours (as Lineweaver's work suggests), then looking for "Earth like planets" is a relatively fruitless exercise, instead we should be searching for Matrioshka Brains or something even beyond those.

This is based on the assumption that the lifetime of a human-like civilization is limited while the lifetime of a Matrioshka Brain type civilization may be billions of years. Feel free to dispute those arguments but I warn you that you had better be prepared to cite references.