Looking for signals from distant civilizations might be an effort in futility, according to scientists who met at Harvard University recently. The dominant view of astronomers at a symposium on the future of human life in the Universe seems to be that if other life is out there, it likely is dominated by microbes or other nonspeaking creatures.
Speakers reviewed how life on Earth arose and the many, sometimes improbable steps it took to create intelligence here. Radio astronomer Gerrit Verschuur said he believes that though there is very likely life out there — perhaps a lot of it — it is very unlikely to be both intelligent and able to communicate with us.
Verschuur presented his take on the Drake equation, formulated by astronomer Frank Drake in 1960, that provides a means for calculating the number of intelligent civilizations that it is possible for humans to make contact with.
The equation relates those chances to the rate of star and habitable planet formation. It includes the rate at which life arises on such planets and develops intelligence, technology, and interplanetary communication skills. Finally, it factors in the lifetime of such a civilization.
Using Drake’s equation, Verschuur calculated there may be just one other technological civilization capable of communicating with humans in the whole group of galaxies that include our Milky Way — a vanishingly small number that may explain why 30 years of scanning the skies for signs of intelligent life has come up empty.
“I’m not very optimistic,” Verschuur said.
Dimitar Sasselov, professor of astrophysics at Harvard and director of the Harvard Origins of Life Initiative, agreed with Verschuur that life is probably common in the universe. He said that he believes life is a natural “planetary phenomenon” that occurs easily on planets with the right conditions.
As for intelligent life, give it time, he said. Though it may be hard to think of it this way, at roughly 14 billion years old, the universe is quite young, he said. The heavy elements that make up planets like Earth were not available in the early universe; instead, they are formed by the stars. Enough of these materials were available to begin forming rocky planets like Earth just 7 billion or 8 billion years ago. When one considers that it took nearly 4 billion years for intelligent life to evolve on Earth, it would perhaps not be surprising if intelligence is still rare.
“It takes a long time to do this,” Sasselov said. “It may be that we are the first generation in this galaxy.”
Several speakers at the event hailed the March launch of NASA’s Kepler space telescope, which is dedicated to the search for Earth-like planets orbiting other stars. Several Harvard-Smithsonian Center for Astrophysics faculty members, including Sasselov, are investigators on the telescope mission.
Sasselov said he expects Kepler to quickly add to the 350 planets already found orbiting other stars. By the end of the summer, he said, it may have found more than a dozen “super Earths” or planets from Earth-size to just over twice Earth’s size that Sasselov expects would have the stability and conditions that would allow life to develop.
If life did develop elsewhere, Andrew Knoll, the Fisher Professor of Natural History, used the lessons of planet Earth to give an idea of what it might take to develop intelligence. Of the three major groupings of life: bacteria, archaea, and eukaryotes, only the eukaryotes developed complex life. And even among the myriad kinds of eukaryotes, complex life arose in just a few places: animals, plants, fungi, and red and brown algae. Knoll said he believes that the rise of mobility, oxygen levels, and predation, together with its need for sophisticated sensory systems, coordinated activity, and a brain, provided the first steps toward intelligence.
It has only been during the past century — a tiny fraction of Earth’s history — that humans have had the technological capacity to communicate off Earth, Knoll said. And, though Kepler may advance the search for Earth-like planets, it won’t tell us whether there’s life there, or whether there has been life there in the past.
Other speakers included J. Craig Venter, Freeman Dyson, Peter Ward, Andy Knoll, Maria Zuber, David Charbonneau, Juan Enriquez, and David Aguilar.
Source: PhysOrg
I’ve read a lot of science fiction featuring ancient and highly advanced alien races, like Arthur C. Clarke’s 2001. The thought that we might be among the oldest civilizations is an interesting one.
Yeah, though it’s depressing that we might be “alone” in our large corner of the galaxy, it would still be neat if future races discovered our achievements long after we died out and called us “The Old Ones”.
Very interesting and puts a few new thoughts out there that the milky way may only have 1 or 2 intelligent civilizations.
I hope not of course. I hope there is more civilizations around.
I think after 30 years of scanning the skies we can safely assume we are one of the first intelligent civilizations in our galaxy. It would help explain why we have yet to recieve a signal from the stars.(excluding the WOW signal, i believe this may have been a passing probe from another civilization, unaware of our position in the galaxy) I dont believe we are the only intelligent civilization in the galaxy, it may be that we are the first to communicate with radio waves and it could another thousand years before another intelligence discovers those signal’s, if at all. It sucks, i know, and the thought that only we are the masters of our destiny is scary. I would love for another intelligent civilization to give us a leg up to inter-stellar travel but alas,as time continues to pass without so much as a beep from aliens, it is becoming harder to believe that we are not the first intelligent beings in the milky way. Do we now need to shift our focus from looking for signals to sending them, as a way of notify those who come after us that we where here, we where alive and we where looking for you.
Sorry for the personal theory on the WOW signal, i had already frogtton the new rules. My deepest apoligies. Wayno.
when you think about it though, we’ve only been listening for these signals for the last 30 years, that means that the furthest radio signal we could receive now would be only 30 light years away, that’s not very far compared to the size milky way
I’ve had the same opinion for many years – primitive life is likely prolific, but technologically intelligent life would be extremely rare, if it exists.
The reasons are simple. Base chemicals that life depends on are relatively common. All you need is the right set of conditions including energy inputs and you could come up with single celled life quite readily. Earth was perfectly happy with that arrangement for about 4 billion years – that’s almost 1/3 the age of the universe!
That complex multicellular life then evolved and that much later humans came on the scene is certainly not a given, far from it in fact. Even modern humans need not have evolved advanced technology – look at current primitive native nomadic peoples that only have what they need to survive.
So yes, finding technologically advanced life out there is almost nil (it would also need to exist at the sane TIME as we do, which again us highly unlikely).
I feel that if there is an intelligent race out there among the stars, they are probably avoiding us. I wouldn’t come here if I was an alien. Wars everywhere and landfills piling up. We must look like a bunch of unsupervised preschoolers to them.
Agreed Dominion.
More over, *if* we do stand at the apex of technological evolution in our corner of the galaxy then it becomes even more critical for us to get out among the stars as a race. What a great tragedy it would be to have all the splendor and marvel that lies within the universe go unappreciated. It’s majesty vastly beyond the understanding of those creatures, less self aware. All the beauty and magnificence born of our own species to simply fall into the dark eternal silence of space and time. Whether our origin is mundane or divine it is a blessing and we are the lucky fated to be alive.
I wrote a book last year, “Can Star Systems be Explored? — The physics of starprobes.” One chapter I devote to some astromechanics, chaos and statistics to estimate based on current data how many star systems would maintain a 1AU terrestrial planet in a stable orbit. I found that out of our whole galaxy about 1-10 thousand G-class stars might support an analogue to Earth. On such planets maybe life could emerge and evolve. Interestingly there should be several of these visible within the local Persius arm within a few thousand light years. We should be able to detect them. Kepler?
Given that only 10^5 years out of 10^9 years of Earth’s has involved us humans, we might indeed be the only intelligent life form in the Milky Way galaxy. We might also take stock of the fact the life evolves in many different paths, and animals, plants, and fungis are the main branches for complex multicelluar life forms. Hundreds of other branches of unicellular life exist in the prokaryotic and eukaryotic sets. So with other planets we might well expect that there are many alternative evolutionary paths life has taken which are not present on Earth.
A few weeks ago I was at a public library waiting for someone, and I picked a book off the shelf with a title like “Encyclopedia of Monsters.” I found myself amused by this as it discussed various monsters from Griffins and Medusas of the ancient world to the Geiger alien that pops out of people’s chests. These products of our imaginations, which included a fair number of space alien/creatures, illustrate our tendency to project ourselves and things we know into the rest of the universe. Further, many of these ideas suffer from certain lapses of scientific understanding, such as the Geiger alien going from the size of a rat to a 7ft ~200kg monster in two scenes. Doubtless if complex life exists in the universe it will mostly be very different from what we imagine.
As for intelligent life there are some potential examples of this. Cephalopods, such as octopi can be intelligent to a degree. Some species have basketball sized brains which take up 1/4 their body mass. They are not social and live only 5 years, so they don’t accumulate knowledge. Yet it is not hard to imagine they have a type of sentience about them. They communicate with body coloring which can vary and fluctuate in clearly complex ways. Intelligent life elsewhere in the universe may be of a sort which operates of vastly different principles we can’t imagine.
Lawrence B. Crowell
My personal theorie is there milions, maybe bilions, maybe much more, inteligent life in the universe. Even in our milk way, this number is big.
# wayno@oz Says:
May 13th, 2009 at 5:21 pm
“Sorry for the personal theory on the WOW signal, i had already frogtton the new rules. My deepest apoligies. Wayno.”
Look, the personal theory thing was put in place because people were PUSHING their complex alternate scientific theories in a blog comment space that is clearly not the correct forum for such things. That is a far cry from simply stating “I reckon such-and-such might be the case”, and admitting it is sheer light-hearted/good-natured/fun speculation.
This is not a USSR communist thought suppression blog – you can express personal feelings on an issue or engage in some pragmatic speculation – just don’t write off other people’s or mainstream scientific ideas and then ‘sell’ your idea to people as truth in 200 words or less.
If intelligent life is very rare, then we may need to look outside the Milky Way for signals from extraterrestrial civilizations. Obviously, communicating between galaxies is inordinately more difficult than interstellar communication given the vast distances (millions of light years) and times involved. The amount of energy alone required for sending a signal that far is mind-boggling.
But…
If intelligent life is really so rare that only one or two civilizations per galaxy rise to spread out through the stars, then eventually those civilizations are likely to want to find out if they are alone in the universe. Once you have conquered your own galaxy, what else is there left to do but reach out to others who might be out there?
That’s why I believe there could be a good chance that the first ETI signal we see could be from outside the Milky Way.
If technological evolution is exponential in nature and travel/comunication time is linear (even if you know how to travel at a significant fraction of the speed of light), then at a point evolution (of an inteligent species) will become so fast that, by the time an answer to a signal/question arrives the sender will no longer be interested in it, or will have already found (simulated ?) the answer by itself.
Imagine technology in Earth a mere 1.000 years from know (a mere 10 generations away) will ANY question that we can pose today still be unanswered ? And that would be if we as a species learn how to stay focused on a multi-generation project.
Just keeping in contact even with its own distant colonies might be a challange in itself, each one diverging faster and faster and becoming a diferrent specias altoguether !
(sorry for the typos, English is not my native language)
There’s no evidence that biological evolution point straight into an intelligent being. Only one out of millions of different species that have populated the earth has evolved in an intelligent being.
I find it ironic that Sentience has to be defined in terms of biology or technology as we understand it.
When thinking of (alien) sentience or intelligence we really do have to (step) out of our own self image and also out of our limited perception of time.
(ok; a hypothetical: please dont flame me 🙂
What if the planet and indeed our sun were the products of a ancient race? The original generation ship perhaps.
The question is, how would we recognize this as being the work of an intelligence by our present standard?
And if there is a pilot for our solar system then our limited lifespan prevents us from communicating with it.
We just call it nature. (as an example)
Regards
Damian K
I feel that if there is an intelligent race out there among the stars, they are probably avoiding us. I wouldn’t come here if I was an alien. Wars everywhere and landfills piling up. We must look like a bunch of unsupervised preschoolers to them.
That might not be the case. A diverse ecosystem so far as we’re aware requires organisms to eat other organisms. By extension of that violence is bound to crop up in the prevailing intelligent race – in some way. I don’t think an alien race would be necessarily offended by the things here on earth, just a little uncomfortable, like when you’re visiting neighbors who argue a lot.
I reckon the significance of the Drake Equation is highly over-rated, and that the equation means little more than nothing. It has some value as a teaching tool, to demonstrate what happens if you juggle probabilities across huge numbers.
I speculate about the abundance of exo-creatures and weeds, and their potential intelligence (or the absence of it) and edibility – and what they might look like. I also enjoy reading other speculations, I think about them, agree or disagree…. but I tend to leave the Drake Equation out of my conjectures and focus on other factors I have learned about, and continue to learn.
It looks like depression got the scientists as well.
Humankind only has about 100 years of technology and the universe is about 14 billion years old.
Imagine only the humankind in 1000 years from now or one million years not a billion and realize that we only start to understand things.
This why I think that some civilization will not talk to us yet because we are not that intelligent and besides that how much can we achieve in such a short life.
If the man would live at least 1000 years it will make a huge difference.
One day we will hear from out of stars!
The trouble with all Drake’s equation type stuff is that we are multiplying together a lot of very uncertain numbers to get a product that tells us either nowhere in inhabited and we’re only dreaming it, or everywhere it inhabited twice.
However, using the one example we have…
There is some evidence for signs of life at the end of the Hadean epoch, about 4 billion years ago, when the earth’s surface was barely solid and the skies were still raining rocks. The fact that it kicked off so quickly suggests that it isn’t insanely unlikely.
These life forms were small and living slowly, and the earth was big. It took a long time before they were living off each other and competing for resources. We have about 2 billion years of not a lot happening. Then we had another 1.5 billion years of not a lot either up to the Cambrian explosion. We could imagine lifeforms on a quieter, smaller planet not getting their Cambrian explosion.
There have been times where the population has been very stable. Ammonites were around for a long time. The lizards and dinosaurs were around for a long time. Bees have stayed the same for a long time. If your top species is a good one, then it might be there for a very long time.
However, shortly before the T-K catastrophe (or slightly after if the latest theories are to be believed) some of the smaller, upright dinosaurs were getting larger brains, with folded surfaces. In which case, it may be that the top species might have become an opportunist with a brain instead of some big thing with large teeth or a large shell. Of course, we don’t really know what these creatures would have become, but I can imagine the earth might have had an intelligence if the comet / volcano / Galactus event had not happened. As it was, it made room for the mammals, and here we are.
I am still optimistic. I don’t think there’s any rush to send radio signals to the stars. Given the timescales, we could easily afford to think about it for a thousand years or so. But, I do think there is something out there, somewhere.
It hits me as very odd that we have these great debates over life in the universe while we don’t know still whether there is life on Mars (a mere 35 million miles away at times). If life on Mars was confirmed to be genetically related to Earth life, then at least one of the transpermia theories are in play. At least two interstellar transpermia theories (one by nobel-winner Svante Arrhenius) would greatly raise the odds of widespread life thru the galaxy.
(Of course, If Mars really is sterile, then perhaps some very peculiar chenistry is at play – and that would also be very important to the discussion of how many planets have at least microbial life).
So, if we ever do look hard enough to find life on Mars, confirmed transpermia, and life was determined to be widespread, we would be left with the Fermi paradox – where are the intelligent ones? If I add this to the painfully slow progress to find life on Mars, then I have one thing to say, even though they’ve probably been here a long time: “Jedi…..welcome to Earth.”
Lawrence B. Crowell:
The Giger alien took about 24 hours to reach full size. Still unlikely, though. In the later films, namely the awful Alien Vs Predator films, the creatures literally reached full size in less than 10 minutes. That’s really just lazy writing. Just for your information. 😉
As for the topic:
I’m thinking the real answer might be somewhwere in between the old and new equations. There are just so many variables.
Suppose intelligent life evolved in the oceans of an exosolar planet (the previous octopus example is a good one). Such creatures might communicate via coloration, and possibly accoustic vibrations in water. Would they even know that there was life beyound the shorelines? Would they have even seen the sky?
On the other hand, an intelligent species may communicate via electromagnetic fields or see only in IR or UV wavelehgths (that would probably depend on the star they orbit). Even if they did pick up a signal from us, they might not even percieve it.
Also, the farther a signal travels, the noisier it gets. By the time a TV signal gets to a intelligent species, it may be so weak and noisy that they would not be able to make out anything useful. The same could go for us. We could be getting signals from aliens all the time, and not know it.
Lastly, there is no guarantee that they would be using radio waves. They might be using particle beams or lasers, or what we percieve as cosmic radiation!
A life form that evolves on another planet with different gravity and chemical makeup that orbits a different type of star (or a brown dwarf, for that matter) may look, think, percieve, behave, and function so different than us that we might not even realise it was alive, much less intelligent.
If there are many intelligent species out there, and some know about us, they may simply be waiting for the right time. As a society, we still have a lot of things to figure out. War, pollution, greed, and self destruction are not things that would contribue to a “Galactic Federation”. Maybe thay are just waiting for us to grow up, or see if we’ll destroy ourselves first.
Perhaps the Kind of alien we are really (wishing) for is an intelligence that has also left their (evolutionary) home ground. ?
Aka: Travels in Space.
Microbial life just is not going to make any good movies.
Regards
Damian K
Infinite universe, Infinite number of possibilities. I believe that the first communication will be through some other medium than electro magnetic. Telepathic, or the quantum stew.
I think Feenixx, Richard Kirk, and Dark Gnat got to the problem with the story’s conclusion : too many variables in the Drake Equation, and some variables in particular are VERY poorly constrained ( i.e. ‘average lifetime of an intelligent civilization’ or ‘length of time civilizations release detectable signals into space’). The equation does make a worthy teaching tool, but with the loose constraints on the variables, you can get whatever number you like. I’d have go with Dark Gnat here: more than a few, less than a lot, IMO. Also, a 30 year search for life in a 13 billion year old universe is several orders of magnitude difference! We need to be looking for the long haul.
I know the “it looks contingent, so it has to be contingent” idea of life history is popular among biologists as well. But I don’t think that this prediction has been soundly tested as of yet. It is probably much too premature to put probabilities on the likelihood of technological intelligence.
Also, it doesn’t tie into the Drake equation as far as I know. IIRC Shostak’s view he would like to see at least a million worlds sufficiently surveyed and predicted that would be accomplished ~ 2025. I run the numbers on the DE and I think (layman here) he may be in the right ball park. So again, probably premature to put likelihoods on the possibility.
Hmm. As for the last point, usually convergence (for example, animals and plants body plans) are taken as opening up the probability to certainty.
I’m currently reading Cavalier-Smith’s theory on neomura/eykaryote phylogeny, as last year there was a large genome study that tested his prediction that archaea and eykaryotes are sisters. I haven’t gotten to the part where he suggests that phagotropy was the eykaryote enabler for mitochondria endosymbiosis. But I seem to remember that they have now found other endosymbiotic prokaryote relationships, so again it doesn’t seem unique either.
Anyway, going back to his phylogeny, it seems like life may proceed by punctuated equilibrium. First life likely evolved the first bacteria in some such event (and later went extinct). Then there have been 2-3 similar major events of “quantum evolution” diversification, each accumulating possible functionality until the neomuran “explosion”. If so, the likelihood for organisms capable of body plans, in a first order model, hover somewhere between inevitable (if functionality is accumulative and endosymbiosis likely) to, say, ~ 2/5 on average (if every 5 major punctuated equilibria leads to eukaryote equivalents within 4 Gy and planet biospheres lasts ~ 10 Gy).
But, as they say, this is just a theory. (Albeit the neomuran theory looks AFAIU tested good.)
And he had access to a cargo hold for bulking up mass.
But the rate of cellular division would be humongous, given the constraints of organism growth.
What we need is a cellular swarm type of animal (think biofilm) that can separate cells, go into exponential division mode in a suitable nutrient solution, and then assemble as the grown monster.
Unhindered by linear growth constraints it would be easy. Bacterias can spawn off multiple concurrent genome clonings (the cloning DNA starts to clone before it is a finished genome), and I think E. coli at full clip can divide in something like 10 minutes. Start with one small individual of, say, 100 g. In ~ 10 divisions or ~ 1.5 h you would achieve the needed ~ 1000 times larger mass to assemble a 100 kg monster.
Your 10 minutes monster strains credulity on account of biochemistry. Perhaps you would need some type of biotech monster. (Nanofactories and transporter assembly. Yes, that’s the ticket, I’m sure… ;-))
@ Torbjorn Larrson OM : Regarding variables( for intelligent civilizations) in the Drake Equation, what equation are you using? Specifically, for f(i), f(c) and f(L). It seems these all bear on intelligence, the last two with technological intelligence, no? Check out the inevitable Wiki page here: http://en.wikipedia.org/wiki/Drake_equation . They do mention these questions in ‘Criticism’ section and do give a variety of responses. I’ve just got problems with assumptions made in the equation. But I do agree that it “is probably much too premature to put probabilities on the likelihood of technological intelligence.” 🙂
Nexus:
“I’ve read a lot of science fiction featuring ancient and highly advanced alien races, like Arthur C. Clarke’s 2001. The thought that we might be among the oldest civilizations is an interesting one.”
Well, tech progress seems so fast that even a few hundred years makes a world of difference. We are talking about billions of years here, but any alien race who are at our year 2200 level, will probably be regarded as “highly advanced” and perhaps even “ancient”.
There’s a cool interactive Drake Equation calculator on the NOVA website here: http://www.pbs.org/wgbh/nova/origins/drake.html . Choose your own values for the different terms and see what happens!
I’m a believer in the Copernican Principle, so wherever microbes and muck are given enough time, intelligent life will eventually develop. It is a matter of immense periods of time, and immense numbers of metal rich stars and planets.
I don’t believe that our co-ordinates in space and time, or even the Earth itself or homo sapiens are special – highly important yes, special no.
However, the Milky Way alone is so gargantuan and almost inconceivably large, the prospects of receiving signals of any sort must be remote indeed – and that’s assuming another civilisation would wish to expend energy on high power omni directional RF transmissions to the stars on the off-chance someone else has their high gain antenna pointing in the right direction (at a time when we’re going low power digital/fibre optical). Even with a perfect TX/RX setup signals from more than a few light years away would be so weak.
So my anti-anthropocentric view – intelligence may be relatively common ( >10^4 civilisations in the Milky Way), but space is so gargantuan. Finding a needle in a planet full of haystacks would be chlidsplay compared to receiving ET’s signal.
All of this is not to say we shouldn’t try!!!
Fascinating subject! While it does seem a downer to lower the expectations, I side with the realistic adjustments.
A lot of the questions asked here inspires me to ask one:
I understand we have determined with some degree of certaintly the conditions and circumstances that brought about our rise.
But considering the time frame (how fast it was for us, reletively), and the multiple different groups of life that we have here, why are we so sure that intelligent life hasnt evolved on earth previously? That’s 3-4 hundred million years worth of odds to consider. Stacked odds as well, since we already have evidence of complex life, at least as far back as the Cambrian.
Id like to see that calculation! Is not the difficulty of finding of that kind of evidence here akin to finding an ET signal?
That would explain the ufo\alien encounters – they weren’t from other worlds, they were merely just arrived from a very long journey out there…
In the movie “Explorers”, the aliens didn’t want to come here because of what we do to aliens in our movies, which is how they learned of us. Just like in “Contact” with all the radio signals spreading out. Perhaps we should blame Hollywood for our lack of friendly neighbors.
In the last 70 years, mankind’s technological progress with nuclear weapons has more than outpaced its progress in getting along with each other. We are like a baby with a gun. With this in mind, it wouldn’t surprise me that the natural evolution of an “intelligent” species would be to eventually annilate itself. It might take a few thousand years or so, but a speck in the grand time scheme of the universe.
Perhaps millenia ago, hundreds of radio or communicative type signals passed us by, and lacking the technology, we of course missed it! The time scales are incomprehensible, and we have been listening for only a moment.
I understand one thing that has pushed me through my life. I have to worry about what is right in front of me, . I have lived in a very rough and tumble world. We worry to much about being alone. We try to reach out and grasp at any straw that may explain our being in this vast universe. We do not yet understand how our own planet works. We have not explored all of our oceans. We have a very big back yard to figure out just in our Solar System. We have only recently develope radio communications, learned to fly and to begin to explore local earth space. I think it is ok to look for intelligent life else where. But…lets first worry about our back yard first, and in doing that, breakthroughts and insights that will lead us on a path of better technical advances to find that ‘other life’ that I am sure is out there. Remember we have just begun to figure out things. Don’t take those ‘ideals’ and principles as written in stone. Things change, and our own intelligence will change. Drake Equation is just another numbers game. Let first save ourselves this place we live on, and figure out the local neighborhood. This rest will come to us. It is what is in our face that is important. Yet I know that there has to be other intelligent life out there. Otherwise it would simply be a waste of good universe realestate. Then again we may be just a Virus.
I remember when some prostegious scientists in the late 90’s said extra-terrestrial life would be limited to just simple bacteria. That was when we were just starting to discover that extra solar planets were in fact real. Now we are hearing the same arguments again. So far we have only discovered about 350. Now, there are billions of stars in just this one galaxy, and we have been to exactly zero. So don’t you guys think it is a little too early to rule out intelligent life?
The universe might well be infinite. We might consider the initial seed of the universe as due to a virtual wormhole. Two three dimensional balls are connected at the horizon into a three dimensional spheres. If the fluctuation is sufficiently large it may lead to a run away situation where the three sphere inflates enormously, in fact into a three dimensional space. The topology is changed and some quantum number is involved with this “transition,” which is involved with inflation. This three dimensional space continues to evolve, which defines the Hubble frame, and points on it might be thought of as moving away from each other — indeed accelerating apart.
So if the universe is infinite, the clearly there are ETs which exist, indeed an infinite number of them. In fact there may be identical copies of ourselves! So ETs probably exist, but the big question is how many are there per galaxy? On the Hubble frame it might be there exist only 1 ET/galaxy on average, or worse 1 ET/n-galaxies, for n > 1 or even worse n >> 1. Of course the galaxies we observe are not on that frame, but along a projective set of rays or light cone which connect to the origin of the universe. So of course everything we observe is in the past, and any galaxy a few billion light years out is in an early enough a state of evolution where ETs become less probable.
Scientifically the big pay off to look for is a terrestrial planet with chemical signatures similar to Earth. A planet with an oxygen atmosphere with traces of methane is a pretty good bet for being a bio-planet. Eventually we might image the body, and if it has oceans, clouds, and maybe green or other colors or spectra associated with photosynthesis, then we have made an important scientific discovery.
Lawrence B. Crowell
An important factor, I think, is a race’s desire to explore. You could imagine, say, a civilization of super-intelligent oysters who simply have no desire to go anywhere or explore anything, or do anything except sit there serenely. Then if their sun goes nova, or their planet gets hit by a comet, they’re fried and their civilization becomes extinct.
Now imagine another race, not quite as smart but with an insatiable appetite for adventure. Setting off on rickety and unreliable spaceships, they manage to set up colonies on other planets before nuclear war or some other disaster wipes out their home planet, and they survive.
May I point out that intelligence is relative intelect too… Intelligence is acqueired, and is not universal in all homosapience!
I would not expect intelligence from a famous
sport star player, although they pocess a great deal of induvidual talent? We acquate a
chess grand master with intellect. But is an talent equal to intelligence? I think not.
We equate our ability to deduce and reasoning with inteligence? But collectively
with our combined induvidual talents we
can call ourself relative intelligence!
We all have certain talents but only a handfull
of induviduals have intellect! Please be humble, we all think that we are more intellectual than the other person, that is why we call them dummies?
I agree with Bravehart, and I’ll take it one step further — outside the human species. Other species are intelligent — they’re just intelligent in different ways.
How can we be so arrogant to claim that we understand how much they do, or don’t, know or understand about the world around them? Every test “we” design is flawed because it’s based on how we view the world. We can’t even test them adequately.
What do you mean a “new” Drake equation? It contains all you need, just stop at the evolution of intelligence.