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Where are they?
Today's headline reads:
Milky Way teeming with earth-like orbs.
They don't have to visit, they can manipulate star patterns for an advertising campaign or a fundraiser. Not to mention solar-powered self-replicating probes. They don't seem interested.
The obvious conclusion is that highly intelligent species do not last very long and are also not very common. Here is my previous post on the Fermi Paradox. Here is Geoffrey Miller on the Paradox.
Posted by Tyler Cowen on October 5, 2006 at 01:24 PM in Science | Permalink
Comments
More galactic real estate for me then.
I do wonder though how many worlds there could be that would not require significant terraforming. We can also assume that any world suitable for human life would have its own (non-sapient) life, and any introduction of Terran species would either be fruitless (because they were so hopelessly out gunned by the natives) or like bringing rabbits and horn toads to Australia. Either way, if we plan on living on those worlds it would probably require either living in artificial and limited habitat-biomes or wiping out most indigenous life.
Posted by: Brock at Oct 5, 2006 2:37:20 PM
26,000 Light Years is a heck of a trip. Assuming that the solar probe (let us ignore self replicating for a moment, and just say they said on a whim to send one to us) could average .3 c (30% of light speed is no mean feat esp. when it has to A) accelerate, and B) slow down to some speed that would give it a reasonable in system time) is ~87,000 years. Add on 26,000 years for a reply, and the civilization would have to wait 113,000 years to even know that hey there is life out there. Not that it would do them any good, what are you going to do trade 26,000 year old recipes? Keep in mind that we have about 13,000 years of some form of society under our belts (well according to Guns Germs and steel, but it will do). Not only that, but the probe could have come lit like a christmas tree, and screaming its heart out anytime except in the past 60 or so years and we'd never have been the wiser.
We just might have to accept that we are in podunkville and all the cool kids (if there are any) hobknobing elsewhere don't want to, you know, do that long distance thing.
Posted by: yasth at Oct 5, 2006 2:48:03 PM
I agree with Brock. But my theory is that species intelligent enough to expand end up politically dominated by preservationist movements strong enough to prevent terraforming. If the European Union won't even support a couple extra genes in our corn, they'll never support changing the Martian climate.
Posted by: DK at Oct 5, 2006 3:01:25 PM
Maybe this is a stupid question and everybody else already knows the answer,
but is there any particular reason we have to believe that we aren't first?
That is, what if there is other intelligent life out there, and we're the top
of an admittedly-not-very-tall heap? Would we be able to detect the equivalent
of us, circa 1100 AD?
[I assume that this is a stupid question because our planet cooled later than
these other planets, or some such explanation that renders my question moot.]
Posted by: hamilton at Oct 5, 2006 3:22:05 PM
For a novel based on the same ideas, check out Charlie Stross's *Accelerando* .
http://www.accelerando.org/book/
Posted by: wuchi at Oct 5, 2006 3:33:24 PM
Everyone else is hiding from the space monsters. Duh.
Posted by: eddie at Oct 5, 2006 3:48:33 PM
"You can infer, but not yet prove, that among them are many rocky Earth-like planets," he said. "Eventually, we hope to find life -- and possibly intelligence there."
What if other societies have also begun the search for intelligent life beyond their world, found us, and decided to pass us by?
Posted by: AZ at Oct 5, 2006 4:03:24 PM
hamilton,
It's not a stupid question, but I think the odds are we aren't first unless we're the only. It took ~4.5 billion years to go from formation of the Sun to digital watches. (There's also no reason to think we evolved particularly fast.) The Universe is ~14 billion years old and galaxies formed fairly quickly. For life as we know it to exist, there does have to be the heavier elements (i.e. heavier than helium and hydrogen) which need to be made from an earlier generation of stars. However, the supernovae which create the heavy elements are from large stars with short life spans of less than a billion years. So there's plenty of time (10+ billion years) for intelligent life to have evolved before us.
Posted by: jon at Oct 5, 2006 4:04:34 PM
"The obvious conclusion is that highly intelligent species do not last very long and are also not very common."
The durability of civilisations is inversely proportional to the weight given to the opinions of its economics professors.
Discuss.
Posted by: Martin at Oct 5, 2006 4:28:27 PM
Assuming that the close proximity of stars near the core doesn't inhibit life, those civilizations might be in relatively easy contact with each other.
Whereas we are stuck out here on the edge. Podunkville, indeed.
Also, the motivations of aliens are obviously inscrutable. They might have the capacity for interstellar flight but utterly lack the inclination.
Imagine their being twice as insular as the classical Chinese, & that would about do it.
Posted by: Anderson at Oct 5, 2006 5:50:01 PM
jon,
Ah. I understand, then. So anything that was "behind" us, as it were,
must be very, very behind. Thank you.
In general:
It seems at this point that any additional speculation might be, well,
highly speculative. I mean, aliens could have all sorts of nifty technology,
no interest in talking to us, no inclination to travel, have died out eons
ago, and so on. But isn't it easier, before we begin generating lots and
lots of reasons why we don't observe other life, to start with the far
simpler supposition that we don't see it because it doesn't exist, rather
than start from the hypothesis that it must exist, and we therefore need
to explain why we don't see it?
Posted by: hamilton at Oct 5, 2006 6:09:10 PM
Hamilton, you've hit the nail on the head. The far simpler supposition is that there's no one out there. Fermi's Paradox is: why? Given all the worlds, and all the billions of years, why hasn't life evolved to the point where we could detect them?
Personally, I think the answer is that life has evolved _beyond_ the point where we can detect them. Even is radio communications is a phase all technological species go through, it's probably a fairly small period of time in the epochal sense. I think there is intelligent, space-faring life but that radio is a very primitive and inefficient way to communicate from their point of view. It's as if the American Indians tried to "listen in" on American Army communications by looking for smoke signals. Does anyone really think that we, the planet-bound civilization that we are, has alredy discovered the best means for interstellar communication? The idea is preposterous.
Posted by: Brock at Oct 5, 2006 7:14:34 PM
We're looking in the wrong place, we're looking for the wrong thing, we haven't been looking long enough, they don't want to talk to us, we're purposefully isolated, we're the first, we're the only, no one uses radio longer than 150 years, God created just the Earth, it's too expensive - the possibilities are endless.
- Josh
Posted by: Wild Pegasus at Oct 5, 2006 7:34:01 PM
They're spending too many of their resources on their own intra-planet wars and elderly pension and medical care programs to fund a search for us.
Posted by: Jacqueline at Oct 5, 2006 9:08:11 PM
This study really doesn't show a lot that is new---the frequency of planets is about the same near the center of the Galaxy as it is in the solar neighborhood. The main new thing is that they found planets around low-mass M dwarfs, which haven't been systematically searched nearby yet. This increases by somewhat the number of planets expected around stars that we could communicate easily with, if there was anyone there to listen.
Posted by: Anonymous at Oct 5, 2006 9:30:36 PM
I'll just mention that if there was a planet emitting the same amount of radio waves as earth just ten
light years away we wouldn't be able to detect with it our current equipment as even our strongest
transmissions would be lost in the background noise of the galaxy at that distance. SETI relys upon
someone deliberately trying to contact us or incredibly strong artificial radio waves generated for some
unknown purpose.
Personally I consider the likelyhood of us being considered dull as mud much more likely than the non
existance of alien civilizations. Possibly there's a couple of human specimens pinned to a card in a
museum somewhere and the only lifeforms that have any interest in us are the galactic equivilant of
entomologists.
Posted by: Ronald Brak at Oct 5, 2006 10:03:22 PM
Astronomers Peter Ward and David Brownlee explain why we are probably the only intelligent life in the
universe in their book Rare Earth. Basically, the conditions to sustain life have to be near perfect and
together with the periodic mass extinction events make the liklihood of intelligent life developing
extremely small if not rare.We may truly be alone in our galaxy if not the universe.
Posted by: Tom at Oct 5, 2006 10:53:05 PM
There are probably self replicating things out there, but I don't understand why everybody assumes that the earth model will be followed on other planets. The odds that cells will develop, let alone, multicellular organisms, ganglia, and communications technology. I think we are looking for something much to similar to ourselves and frankly the universe is not big enough nor old enough for it to be likley that we will find what we are looking for.
Posted by: josh at Oct 6, 2006 9:36:11 AM
I make it a policy not to read any story with the word "orbs" in it.
Posted by: Buce at Oct 6, 2006 10:55:45 AM
"Astronomers Peter Ward and David Brownlee explain why we are probably the only intelligent life in the universe in their book Rare Earth."
How are you using "probably" in that sentence?
We have no real clue as to the parameters of the problem. Our speculations, either way, are simply quaint.
Posted by: Anderson at Oct 6, 2006 11:06:34 AM
Much of this discussion is akin to the theory that the Biblical rapture has already taken place and that we are what is left behind.
Posted by: Buce at Oct 6, 2006 11:54:28 AM
The amount of time it takes to reach another planet that is habitable but uninhabited is irrelevant, as far as the future of the human race is concerned. If we send out 1000 probes with humans in suspended animation to habitable planets, and only a few them manage to produce a viable civilization when they reach their new worlds in 5,000-50,000 years, that is enough.
Posted by: Thelonious_Nick at Oct 6, 2006 12:04:24 PM
A few possibilities:
1. Getting from fire and pointy sticks to spaceships is a long, multi-generation process. Building a civilization that lasts long enough for it to happen, without degenerating into a tyranny that actively interferes with the process of figuring out how to build spaceships and the countless technological marvels needed to keep people alive inside them, is hard. We've had many thousands of different civilizations on Earth, and only a handful have ever even come close to being what's needed for an intelligent race to get to the stars, and even those are showing signs of becoming actively hostile to the activities needed to finish the job.
2. There seems to be a lot of dark matter out there. If it can be converted to regular matter, or otherwise turns out to be useful, people with spaceships may seek out concentration of dark matter and ignore star systems entirely.
3. Star systems are a giant pain in the ass in many ways. Lots of radiation in unwanted wavelengths that has to be shielded against, too much space junk that could poke holes in your hull, getting rid of unwanted heat gets trickier if you're getting blasted by bright sunlight and so on. And if you've got a starship, you already know how to build closed ecosystems, and you don't really need a habitable world anymore. And you've probably also got a mass converter, since you need positively enormous amounts of delta-vee to cross interstellar space in a reasonable amount of time. So even without dark matter, aliens might look for brown dwarfs, bits of rock floating far from star systems, maybe extreme outer planets of star systems, and the galaxy will have to be pretty crowded before they'll consider getting close to an active star.
4. As someone said above, looking for aliens with radios is like Indians looking for European cultures by checking the sky for smoke signals. Wormholes you can walk through may be insanely expensive to build, but a tiny wormhole you can send a few particles through gives you a tool combining the best features of a cable and a radio, making both obsolete and enabling communication between star systems without a multi-year lag. So really, radio silence from the rest of the galaxy is pretty much what we should expect.
Posted by: Ken at Oct 6, 2006 3:21:47 PM
Scott Adams (dilbert.com) explained it perfectly:
The last invention ever made will be the holodeck. Once you have a choice between working on the intersteller probe, or getting a hot oil massage from a simulated Cindi Crawford and Marylin Munroe... well that's it for progress.
And yes, I've often likened SETI to a smoke signal search.
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