I went and watched Jill Tarter’s acceptance speech for her TED Prize earlier this month. I’ve been aware of Jill’s work for a long while now, and have been a (somewhat silent fan). But I was unaware of the TED prize until it came up in xkcd.com. (Kudos to xkcd for that!)
I really liked the grand view she takes of the universe and our place in it. She eloquently points out the fact that swirls of gas and dust have collapsed and developed into a form which is aware of itself and wonders where it comes from, and whether it’s alone. When you think about it like that, it’s a little unnerving.
It really is hard to imagine a more profound discovery than to definitively prove that there is sentient life elsewhere in the universe, perhaps relatively close to our little spot in the suburbs of the Milky Way. Science fiction has for decades explored the many possibilities of the forms that such life might take. Movies and TV have focused mostly on the humanoid forms since the costumes are easy. One might make arguments about the typical strength of materials relative to the gravity of habitable planets, etc., and about convergent evolution. But to me it seems exceedingly unlikely that intelligent life elsewhere has two legs, two arms, or even a head like ours. It would seem to me to be a long shot that they are RNA/DNA based, or even based on amino acids and proteins. It could be they they are tiny, and have a hive-like culture. Or they could be vast stadium-sized creatures who live for millennia and float in their densely gaseous outer planetary layers. The possibilities are endless. The chance that they are anything like us, though, seems truly remote.
But here are a few things we can say relatively confidently about intelligent/sentient/technical beings elsewhere that we may some day detect:
1. They are made out of the same kinds of atoms and molecules that we find here, possibly including
iron/cobalt/nickel, other metals, and lighter atoms like carbon, oxygen, nitrogen, silicon, and on and on. These atoms came from the explosions of the first stars in their final death throes, and that’s what’s out there to make life from.
2. They need energy to survive, and may have learned how (as we have) to access alternative sources of energy to drive their technology. Some of these sources may be entirely unknown to us (yet – that’s one reason why we need to keep pushing the high energy frontier) but available all around us if we just knew what to do.
3. They almost certainly use ordinary electromagnetism and the nuclear forces in their technology, which is based on the ordinary matter from #1. Clearly light, and all the other forms of electromagnetic radiation are so ubiquitous it is hard to imagine they’ve overlooked it. Similarly for the nuclear forces. This is our doorway into ordinary matter at reasonable temperatures. (This having been said, humans on earth only recently started to learn how to control these forces. And, given #2, maybe the aliens have moved on to better things.) Their electromagnetic emanations, anyway, are just about our only hope of detecting them.
4. They are almost certainly either far older, and more developed than we are, or far younger and more primitive. Humanity has only been truly self aware, and headed toward advanced technology, in the very recent past, perhaps the last few hundred thousand years. Compared with billions of years, this is a tiny slice of time.
5. They are very, very far away and it would take an excessively long time for them to cross the vast distances between stars. (I view faster-than-light travel or communication as a non-possibility, practically speaking, for even the most advanced life forms. I know this is not going to make me popular with the alien fans out there, but outer space is really, really big.) It takes light many thousands of years to cross the vast stretches of space. You have to really want to go interstellar if that’s what you’re about, and you have to abandon the rest of your society and all the support you get from it once you leave.
For me the bottom line is that even if we found aliens by peering out into space with our detectors, we may realize they are out there, but they are probably not coming here. Somehow that makes me feel more lonely, not less. And if they did come here their technology is so advanced that they would hardly regard us as worth of any sort of interest or notice. Our planet might have some interest for them in terms of resources to exploit, but that is probably about it. We’d just be in the way, at best. We can forget about communicating with them…let’s just hope they don’t want our protein.
Anyway, give Jill a listen she is very eloquent on the subject.
February 25th, 2009 at 8:06 pm
Detecting their EM emanations is indeed one way one may hope to discover the existence of some ETs, but if said ETs are intentionally trying to communicate, they might instead use neutrinos which can travel longer distances that photons without interruption. Tony Zee is a strong advocate of this possibility and has some interesting papers on the subject:
The Cepheid Galactic Internet
http://arxiv.org/abs/0809.0339
Title: Galactic Neutrino Communication
http://arxiv.org/abs/0805.2429
February 25th, 2009 at 8:27 pm
I think we can relatively confidently say that ET got there the same way we got here; i.e. evolution.
February 25th, 2009 at 10:07 pm
John- I read plenty of sf (’sci fi’) as a kid, as did many (most ?) physical scientists, and I would love for us to find ET (or them, us) as much as anyone, as long as it was the ‘good’ kind of contact. But — we alas haven’t seen any compelling evidence of them, yet, even though humanity has been ‘waiting’ for what 50-100 yrs now?
And so I’ve kind of settled on the fact that it won’t likely happen in my life (which could be a good 40-50 yrs more), and I have to be OK with that.
In fact, you can estimate away on Drake eqn factors as much as you want, knowing that for several of the factors, there is absolutely no way at this point to definitively get any actual ballpark figure even, and you won’t be able to conclusively *prove* that life must have evolved with a high probability on *any* other planet in the Universe.
I *believe* it probably has — I just don’t want to have waiting for them being a big part of what I do in my life. There is to much for me to do, and revel in, on Earth to be bummed if we don’t.
And yes, despite the long distances between stars.. the Fermi paradox still bugs me.
(Actually, a fascinating and not too hard special relativity calculation shows that *if* you could make a rocket that could accelerate constantly at 1G, and evade all micrometeorites and such, and you go across the Galaxy at this rate for 50 yrs, then *decelerate* at 1G for another 50 yrs — you’re across the Galaxy in 100 yrs proper time (that’s roughly the numbers). cool, huh?! This paper is somewhere on the arxiv actually, I think in astro-ph, in the last few years.).
Having said that, I totally honor and respect and applaud and feel we should financially support Tarter and good diligent folks like her. It’s true — if and when we found evidence for ET, it would be *Earth*-shaking for humanity.
February 25th, 2009 at 10:07 pm
For the multimedia oriented.
Jill on nova.
Our place in the universe.
Interview from Bad Astronomer Phil.
And at the Perimeter Institute.
February 25th, 2009 at 10:10 pm
Why would you assume that just because an alien civilization is technologically advanced they would “…hardly regard us with any sort of interest or notice.”? We are far more advanced than the vast majority of life here on earth yet the discovery of a new species of frog, fish or bacterium is always met with excitement.
I can only imagine the years worth of research and controversy that would be created over the discovery of simple microbial life on another planet or moon.
February 25th, 2009 at 10:32 pm
I guess, Stefan, that I think that they would be more advanced than us because they came here rather than the other way around. Why would they care about us? They are probably used to finding all sorts of creatures where they go. They might initially regard us with caution, then take whatever it is they came to get. Let’s not tell ‘em we have nukes right away….but I bet that’s not enough to discourage them.
February 25th, 2009 at 10:59 pm
> But to me it seems exceedingly unlikely that intelligent life elsewhere has two legs, two arms, or even a head like ours. It would seem to me to be a long shot that they are RNA/DNA based, or even based on amino acids and proteins. It could be they they are tiny, and have a hive-like culture. Or they could be vast stadium-sized creatures who live for millennia and float in their densely gaseous outer planetary layers. The possibilities are endless. The chance that they are anything like us, though, seems truly remote.
Do we know how sensitive evolution is to initial conditions? Have we adequately characterized the problem space? With no other examples and not receiving a signal we will have to rely on simulations of the universe to truly answer the question. If we can simulate a reasonably large percentage of the universe in adequate detail we can simulate evolution on distant planets that have a very different makeup. If moore’s law is correct we’ll be doing this in no time. My space science professor ran a simulation of 2.5% of the visible universe. The simulation is sparse, as you would imagine, and actually not all that big: http://www.colorado.edu/news/releases/2007/478.html
What’s the biggest simulation you know of?
February 26th, 2009 at 2:50 am
Well, now.
“They are made out of the same kinds of atoms and molecules that we find here”
In discussing the potential variety of extraterrestrial life, I would not rush to make claims such as these. Life is a process of energy consumption, self-replication and evolution, and as such replicable in a wide array of media, not tied to the periodic system and the “empty” space it’s members bounce around in. Intelligence is (as it appears to be most likely at the moment) likewise a process of recursive systems modelling likely tied to structure, not the medium (if it were the medium, then the discussion becomes pointless, since intelligence would require a good replica of a brain which would require a similar body to support it). Therefore, any sufficiently “perturbable” environment could, in a theory not far off from discussing ETs in general, produce life-like and intelligence-like processes.
An extra helping of Greg Egan is in order, methinks.
February 26th, 2009 at 3:37 am
Yes, while it is likely that any ETs we contact would be far in advanced of us technologically, it does not necessarily follow that they would not be interested in us. For example, they could be interested in our art. There are people who have paid lots of money for paintings done by cats and monkeys, so maybe they would be interested in how we perceive our environment.
February 26th, 2009 at 4:16 am
“sentient/technical ”
Why are these always considered together? The time period for which they have each existed on our planet differ by several orders of magnitude.
February 26th, 2009 at 5:00 am
CNN reported yesterday that Univ of Edinburgh did a simulation to find out what percentage of planets harbor life:
http://www.cnn.com/2009/TECH/space/02/25/galaxy.planets.kepler/index.html
Does anybody know more about this research?
Is this just a glorified Drake equation approach or did they actually simulate star and planet formation? The article seemed confused. Anybody have any links?
February 26th, 2009 at 8:07 am
Given the age of the universe and the time-scales of star formation, it’s likely that any aliens contacting us (rather than us contacting/discovering them) would be more advanced than us by hundreds of millions or billions of years. While biological and technological/cultural evolution aren’t quite the same thing, if we use biological evolution on Earth as a crude order-of-magnitude estimate that probably understates the difference (because change over time speeds up), they would be to us as we are to somewhere between early bacteria and early multicellular lifeforms. If they travel to meet us, they’ve either discovered some loophole in special relativity or overturned special relativity at a fundamental level, in which case their technology is incomprehensibly more advanced than ours; or their lifespans and time horizons are sufficiently long that a thousand-year-voyage (from the perspective of wherever their home system is) is an endeavor worth undertaking.
In any event, their perspectives and abilities would be deeply alien to us, and the appropriate model for imagining first contact is not, “Humans meeting other humans,” but, “Humans discovering a new bacterium or jellyfish.” You don’t trade with bacteria, and you don’t conquer them, either, because they don’t have anything you want in any realistic sense: you study their lifecycles and ecology, you communicate with them in a crude fashion by sending signals on a level they can understand, you take them apart and put them back together to see what makes them tick, occasionally you farm them, and sometimes you wipe them out with antibiotics because what they’re doing isn’t convenient for you. One of the least-bad treatments of aliens in science fiction is 2001: its aliens are enigmatic and inconceivably powerful, and they interact with humans on the kind of level more appropriate to their scale.
February 26th, 2009 at 8:26 am
We should try to decect signals from ETs that are coming from distant galaxies. This is why:
Civilizations that are facing problems, e.g. because a nearby star is about to explode, may decide to send very powerful distress signals. If such a civilization is completely machine/robot based, they could simply transmit all their date via radio communications to another civilization.
They don’t have to wait until they get a reply. After sending the distress signals, they can send information about their civilization, how to build their machines starting from scratch etc., right away. Then they repeat the distress signals and the information over and over again.
When the effects of the supernova destroys the civilization, the signals will still be on their way. If some hundred thousands years later the distress signals are picked up by another civilization, they can record them. If they figure out how to decode them, they can then rebuild the destroyed civilization.
The inhabitants of the civilization will then come alive again. To them it will feel like waiting for the disaster to happen and then suddenly finding themselves at a completely different place with no recollection of any disaster (because they were reconstructed from the data they sent before the supernova destroyed them).
Now, the distress signals could be so powerful that they could still be detected by us from a distance of a billion lightyear, if we specifically search for it. Within a radius of a billion lightyears there may be a few civilizations every year who face wipe-out. So, it’s a bit like the fact that some very powerful signals from rare events tend to come from great distances and are still relatively easily detected here on Earth (e.g. gamma ray bursts).
Another factor here is that the early universe was a more dangerous place. This would have inhibited the formation of a civilization, but also any civilization that somehow managed to develop had a larger probability of having to deal with being wiped out.
February 26th, 2009 at 9:38 am
Great article. This is why I come here. Also enjoy reading the comments.
February 26th, 2009 at 10:05 am
When an intelligent species becomes advanced enough to create virtual realities, they close up their planet and lock themselves in rooms to spend the rest of their lives in an existence of their own choosing. For them, the “real” world can go hang.
We are on our way to doing just this.
February 26th, 2009 at 1:32 pm
“The possibilities are endless. The chance that they are anything like us, though, seems truly remote.”
As long as they’ll have sex with us that’s ok.
“Clearly light, and all the other forms of electromagnetic radiation are so ubiquitous it is hard to imagine they’ve overlooked it.”
Just because it’s ubiquitous doesn’t mean they have any use for it, and maybe there’s something we’re overlooking? Maybe there’s something more ubiquitous, but we are unable to comprehend it? Hard to believe we great meaningful humans are missing something major, huh?
“They are almost certainly either far older, and more developed than we are, or far younger and more primitive. Humanity has only been truly self aware, and headed toward advanced technology, in the very recent past, perhaps the last few hundred thousand years. Compared with billions of years, this is a tiny slice of time.”
But life has apparently been on Earth for 3.7 billion years. That means life has existed so far for about 2/3 the lifetime of the universe itself. And that’s just in this one spot.
“For me the bottom line is that even if we found aliens by peering out into space with our detectors, we may realize they are out there, but they are probably not coming here.”
That would be really interesting – especially if we had no way of getting to them.
Maybe they’ve already put us in their zoo.
February 26th, 2009 at 1:38 pm
We’re already there, solstice. In fact, we are the VR. Or at least the AI that makes the alien’s VR world seem more believable.
February 26th, 2009 at 4:43 pm
Do you have any more information on this:
——–
She eloquently points out the fact that swirls of gas and dust have collapsed and developed into a form which is aware of itself and wonders where it comes from, and whether it’s alone.
——–
A pointer to some more details?
thank you
February 26th, 2009 at 4:44 pm
If other forms of life are based on chemicals, then they probably are based on DNA or RNA, according to William E. Loomis, author of “Four Billion Years: An Essay on the Evolution of Genes and Organisms”. He states that nucleic acid polymers have the potential for carrying large amounts of information and have evolved onto efficient autocatalytic substances. They are unique in this respect.
February 26th, 2009 at 6:05 pm
Well, certainly 2) above is most likely crap, and reminds me of Steven Weinberg trying to justify the SSC to Congress as a tool for cancer research (never trusted a particle physicist since then). As for ETs likely being millions to billions of years more advanced than us, also most likely wrong, at least in terms of contact. Speciation time scales on earth are only a few million years for mammals and it’s certainly impossible to predict what a culture that lasts orders of magnitude longer than that is likely to want to do or what they would find interesting (the trouble with aliens is that they are ALIEN) (sorry, can’t remember the source for that). Thus contact by definition would most likely be with cultures that differ in age by only hundreds of thousands of years, at most. I’d certainly find learning about Peking man directly quite interesting…..
Of course, given the other constraints, this COULD effectively mean that we are alone in the galaxy (there being few cultures existing at the same time with anything in common).
February 26th, 2009 at 7:10 pm
John wrote “and you have to abandon the rest of your society and all the support you get from it once you leave.”
Not true at all.
It seems very likely to me, almost inevitable in fact, that sooner or later all remaining humans/robots will “fly the nest” and leave the solar system at the same time and embark on synchronized “sallies” for want of a better word, reconvening every couple of centuries to exchange notes on all the planets they have fanned out in their journeys to explore.
In fact, I maintain that is why we haven’t, and are unlikely to, detect alien EM signals – They spend most of their time tucked up in cryogenic chambers in large interstellar space ships travelling at 0.99c to their next stop-off to explore and to their next rendezvous.
Why need they signal, when they know they will rejoin the rest of their kind in due course and an EM signal will hardly only shortly precede their arrival?
February 26th, 2009 at 7:12 pm
How do you know they are not here now?
Maybe they can slip into a body, as easy as you can slip out? Some fictional story perhaps about the encumbrance of the suit being so heavy it makes for some forgetfulness about ones origins, and slows the thinking? If it can happen to us, then why not them?:) You pay a price.
If so advanced then, why can they not mask their appearance within the confines of ones own human experience and allow you to go on your way?:)
Best,
February 26th, 2009 at 7:18 pm
John, I just heard yesterday on this topic from Sir Martin Rees, Astronomer Royal and President of the Royal Society. He also thinks that aliens if they exist are very different from us and certainly do not appear in a humanoid form.
What is interesting though is that the universe is probably much bigger than the part of it that we can observe (10^10 l.y.) . There are some speculations that it can be as vast as 10^100 l.y. which means that it is very likely that there is life out there. But of course it actually doesn’t mean anything because for us as humans it is not enough just to know that somewhere in the vastness of the universe there is life, for us it’s important to contact it. And it’s beyond the capabilities of our technology and our physical theories.
Also Sir Rees touched upon the evolution yesterday and suggested that human species is not the end of the process. Obviously we have more thatn 5 billion years before the sun dies and it’s not only aliens but it’s also our own posteriors at this planet who will be to us today as we are to simple bacteria.
February 26th, 2009 at 9:49 pm
It is worth reading Prof. Nick Bostrom’s arguments regarding anthropic bias as it relates to where extraterrestrials are — a relatively easy introduction is his article in the MIT Technology Review: http://www.nickbostrom.com/extraterrestrial.pdf
A distillation of some ideas/reasoning that was in his Phd thesis at the LSE.
We should strongly hope that we do not find life elsewhere. To simplify his argument, if we find life on Mars or Europa, that would mean life is relatively widespread, and the ‘Great Filter’ that has resulted in our NOT being contacted by extraterrestrials lies ahead of us.
February 27th, 2009 at 12:02 am
Of course Prof Nick Bostrom is more famous for his Simulation Argument.
http://www.simulation-argument.com/brueckner.pdf
“The simulation argument purports to show, given some plausible assumptions, that at
least one of three propositions is true. 2 Roughly stated, these propositions are: (1) almost
all civilizations at our current level of development go extinct before reaching
technological maturity; (2) there is a strong convergence among technologically mature
civilizations such that almost all of them lose interest in creating ancestor‐simulations; (3)
almost all people with our sorts of experiences live in computer simulations. I also argue
(#) that conditional on (3) you should assign a very high credence to the proposition that
you live in a computer simulation. However, pace Brueckner, I do not argue that we
should believe that we are in simulation. 3 In fact, I believe that we are probably not
simulated. The simulation argument purports to show only that, as well as (#), at least
one of (1) ‐ (3) is true; but it does not tell us which one.”
February 27th, 2009 at 1:39 am
The thing is, given the assumptions:
1) Technologically advanced aliens exist somewhere in our galaxy
2) Their civilization has a lifespan of at least 10’s of thousands of years
3) They have some interest in non-sentient and sentient life
4) Slow interstellar travel (<0.5) is technically possible
Then it’s completely plausible that probes are in our solar system and have been for a very long time. Living worlds are detectable by telescope across the galaxy; earth’s photosynthetic signature has been visible for billions of years. A program of mass-production of long-lived sublight probes is foreseeable even with our level of technology. If AI is possible, it’s reasonable to assume the probe would be an AI.
If you believe ET’s are somewhere in the milky way, at least one should have a probe in our system. The fact that UFO buffs are all flakey and have cheezy imaginations, doesn’t mean there is no presence. If there are any ETs, then quiet, old, non-interfering probes are a possibility. The fermi paradox is a very real puzzle.
February 27th, 2009 at 7:28 am
Actually, there is even an ET who is monitoring this very thread, see here
February 27th, 2009 at 7:31 am
Sometimes, for amusement, I wonder just how much truthiness there is in the idea that aliens will be incredibly different from us. Here on Earth, evolution keeps using the same general solutions to deal with the world, such that there’s really only a handful of “designs” out there (here, at least). I also imagine that your biology and ecology puts great constraints on your chances of becoming a technology-wielding civilisation. For example, living in a pool of boiling mud may not be the best plan if you have loftier goals. So, it seems to me, that conditions that are earth-like would be super-conducive to intelligent life developing and thus our aliens have more chance to be towards the similar side of the spectrum than the utterly bizarre side.
I also can’t help but be amused by the idea that any aliens that do visit the earth tend to be seen as doing so on the behalf of their giovernments or worlds – like in an official capacity. Could be just a coulple of bums that arrive in no offficial capacity whatsoever.
February 27th, 2009 at 8:13 am
This is sad. Jill Tarter has wasted her life being obsessed with ETs that have an infinitesimal probability of existence. Human functional equivalents (Carl Sagan’s term) are unlikely. Human-like intelligence is no more expected from biological evolution than elephants with long noses or a particular type of crested bird. To claim otherwise is to inject teleology and purpose in into evolution. In his book “Are We Alone?” Paul Davies points out that if ETI is found, then the Darwinian model of evolution is false and some sort of purposeful entity (God?) is driving the evolution of the universe.
February 27th, 2009 at 8:54 am
Citizen from Birth:
The paper is an extension of the Drake equation, moving away from the steady state equilibrium picture of the equation by means of Monte Carlo simulation, and incorporating more of what we actually know. To a non-astronomer, the paper looks good. It’s plausible that the predicted numbers of ETs lie in a very wide range from a few hundred in our galaxy to almost a million, depending on assumptions. I think this means a rational person assumes there are some, perhaps many, ETs out there.
The Fermi paradox is more of a problem on the high end of the estimate. Otherwise, the ETs are too far away to find or communicate with, unless they send out many probes (it was this travel idea that motivated Fermi – ‘Where are they?’ means, ‘Why not in my corner bar?’).
Questions of motive or appearance are not terribly relevant to the discussion. If even slow interstellar travel is possible, the only real question is whether it is adaptive in the Darwinian sense. My sense is that, if it is at all possible either to have a self-sustaining economy in outer space, or to terraform planets, then interstellar travel is indeed highly adaptive because those societies that practice it will reproduce much faster than those that don’t. I should think that’s fairly clear. That is, the interstellar probes don’t cost their parents much, and create self-sustaining children. Not everybody in the parent society has to care much or even approve.
But if that’s clear, then the Fermi paradox comes back, with force. Then, the rational assumption is that we are right on the cusp of all this stuff happening – we are among the first, perhaps the first, ET in a rather large volume.
Regards,
Mike Gogins
February 28th, 2009 at 3:48 pm
I’m not very optimistic about intelligent civilizations in our galaxy, given the very high possibility of self destruction with their own technology, but non-intelligent civilizations, well that’s a different story because the range is from microorganisms to many many other types of non-intelligent life!
March 1st, 2009 at 10:08 pm
Hexapodia as the key insight.
My only gateway onto the Net is very expensive. Is it true
that humans have six legs?
March 1st, 2009 at 11:00 pm
To further discuss the distances between us and them we are typing about, we must take into account that a civilization as advanced as ours or more could exist out there right now but we will never know. Suppose we discover that there exists bacteria or some primitive life somewhere out there. Problem is, when we look into space we are looking into the past. We see this life in an undeveloped form, when in actuality as we are observing this they could be just getting the information of the early Earth, seeing our ancient ancestors! Wouldn’t that be funny. Or suppose we observe an advanced civilization. Communication could be pointless, maybe by the time we get that information the civilization could long be gone.
March 3rd, 2009 at 4:41 am
Manual trackback:
Fermi paradox meets the (geological) timescale
http://lablemminglounge.blogspot.com/2009/03/fermi-paradox-meets-timescale.html
March 3rd, 2009 at 10:41 am
Otis said:
“In his book “Are We Alone?” Paul Davies points out that if ETI is found, then the Darwinian model of evolution is false and some sort of purposeful entity (God?) is driving the evolution of the universe.”
What?? How does the presence of other beings in the Universe mean that some supposedly higher power made everything? Please elaborate, if you can.
March 4th, 2009 at 5:29 pm
“Our planet might have some interest for them in terms of resources to exploit, but that is probably about it.”
What earth resources do you think that an advanced species would want? If they have interstellar travel capabilities, it’s very likely that they have no need for our primitive forms of electricity generation. For example, they might need fresh water (see V
, but they could easily desalinize sea water. I can’t see them being all that impressed by our natural resources; we would probably have a far greater interest in their technology. What elements and compounds are easily found on earth that are rare in the rest of the universe?
They might be very interested in our creative output. They might be entertained by CV, impressed by paintings, enjoy the pulses of air pressure that we call music.
They might find earth organisms very interesting, though I would imagine them to have very advanced genetic engineering, and look upon our genes like a primitive living museum.