It seems that everyone just assumes the universe is teeming with intelligent life. They make statements that there are so many stars and galaxies and so on that there must be many civilizations out there.
I’m not convinced. Having taken math in college, I know that a very small probability of a very large number is not always large. Like a limit in Calculus…if the probability dives to zero faster than the number of stars increases you can get zero…or even a number like 1.
So, I’m not convinced that the universe is teeming with intelligence.
I am not an astonomer or trained in anything close to it but my thoughts are:
I find it strange that it took half the lifespan of the sun to create intelligent life on Earth. Heck, the lifespan of life on Earth is probably NOT = to the lifespan of the sun so we may actually be relatively close to the end of it so it might have taken most or nearly all for this to happen. I find this coinicidence strange.
Why so long to create life beyond bacteria or cells? The Earth was around for a long time before it happened. Maybe it was an ‘accident’ (improbable?). Maybe if/when we get out there all we’ll find is bacteria and single cells?
Along the same line, what about sentient (intelliegent?) life? It was something like half a billion years??? Strange…maybe we’ll get out there and find life but no intelligent life?
Some ancestors of us went along for million+ years and didn’t advance on technology. Maybe intelligence does not mean technology? Maybe we’ll get out there and find intelligence…just not technology?
What is the rate-limiting step here?
Astronomers are finding solar systems out there…but they seem to be flawed. Maybe it is rare to have a stable solar system and that is the rate limiting step or is combined with the above.
I’m not convinved the universe is teeming with intelligent aliens. I’m willing to be convinced…but cannot accept the ‘universe is big’ arguement as evidence. Yes, the universe is big…but maybe the probability a technilogical civilzation develops is much smaller than it is big?
Well yeah, given that we Humans have had radio for just over 100 years as compared to the hundreds of millions of years of Life on Earth, or the 3+ billion year lifespan of the solar system, it is a bit of a stretch to assume large values of N where N = Number of Technological Civilizations.
I’d consider it an almost absolute certainty that the Star Trek / Babylon 5 model of hundreds of roughly equivalent spacefaring civilizations arising all at the same time in a small area of space is impossible.
On the other hand, I think we’re already learning how completely off base we are on this planet as to this idea that animals and the like are “lesser beings” completely devoid of intelligence. There may come a day when the joke is about how stupid Humans are that we blundered around killing everything while believing ourselves superior; much like how the tables have turned in our culture and we no longer have “stupid weak female” humor in movies and TV, but “stupid weakminded males” humor.
Who said anything about teeming? I do believe the probability of humanity being the only intelligent life to be incredibly remote, but it’s impossible, at our stage of technology, to have a clue if it’s us and one other, or us and a hundred million other intelligent species. I’d say it’s possibly more than just us plus 1, probably much more. I mean, just look at the universe, man. It’s stinking huge!
The problem with answering this is that we have a sample of 1. There really isn’t any reasonable way to make general statements about life in the universe when we only know about life on one planet.
We used to think that planetary systems would have small planets close to the star and big ones farther out, just like our solar system. Then in 1995 we found 51 Pegasi b, which our theories had said shouldn’t exist. I’m sure that, if we do find life on other planets, it will have some characteristics that will go against our assumptions about life.
Flawed how? The systems we are seeing are not unstable in the sense that the planets are unlikely to be thrown into interstellar space or to collide with a star on a timescale of a few billion years.
I don’t think the galaxy is teaming with intelligent species, because it it were, we’d probably see some sort of evidence for that. Or maybe we do see the evidence, but misinterpret the alien stellar engineering projects as natural phenomena.
Since life on earth began very quickly after the earth cooled enough for liquid water to condense, it doesn’t seem out of the question to imagine that life is not an incredibly unlikely phenomenon. But since the first 2 billion years of life on earth featured only bacterial grade organisms, and the next billion years featured only single celled eukaryotes, it doesn’t seem that multicellular life is particularly inevitable. And we’re just not sure why multicellular life arose 650 million years ago in the pre-Cambrian, and of course we’ve got the whole 659 million years since the evolution of multicellular life until our pre-human ancestors evolved a million years ago, and only 50,000 years ago Homo sapiens was just another species of large mammal that happened to use tools a lot more than other ape species.
There doesn’t seem to be any inevitable ladder leading straight from a bacteria at the beginning to an intelligent tool using biped on the other. Or even a straight line from a bacteria to a worm. It wouldn’t suprise me to find hundreds of planets in our stellar neighborhood with life, and allmost of that life is bacterial grade, with only a few planets with multicellular life. If the universe is teeming with intelligent spacefaring aliens, the next question is, where are they?
So either they aren’t very common, or they go to some lengths to keep their heads down. And why do they keep their heads down? Berserkers.
In calculating the probability of discovering intelligent life it’s assumed we must first find planets just like ours. Where the hell is it written life can only exist as carbon based? If we ever do discover life on other planets I bet it’ll look like sci fi set drawings that where discarded for being too bizarre.
Well we are a bit of a remote backwater. We might think we are the pinnacle of civilization whereas they are rocking out in the core. Who knows right? I don’t think there is really any way to derive such probabilities.
Why do you say that? Maybe there IS a reason that life would be carbon-based. I had some chemistry and I seem to remember that carbon has a flexibility in interactions that other possibilities don’t. Also, isn’t carbon ‘relatively’ common?
http://www.theguardians.com/Microbiology/gm_mbm04.htm Part of the reason is extremophiles. Life has been found in places that would have been thought impossible not long ago. So the equations have been adjusted upwards.
I first want to know how many civilizations is a teem.
The assumption that we’re at the forefront of development in much sf bugs me also. ST at least often had plots involving advanced races - not just Q, but the Organians also. One show mentioned a race that seeded the galaxy with human like organisms - which doesn’t explain why we evolved here.
I think one can invent a background with 100s of roughly similar races - but the author must not treat it as a given - which usually happens. It’s kind of a meta-Fermi paradox.
You have a point there. I looked up the most common elements in the Universe and although we shouldn’t deny the possibility of a creature made of solid Neon the fact that Carbon has such a massively high melting point makes it the clear favorite for extraterrestrial life.
No, we really wouldn’t. A civilization as advanced as ours could exist around Alpha Centauri and we wouldn’t even be able to detect its radio and TV broadcasts with our current best radiotelescopes, assuming the putative aliens use a power level on a par with our own. Unless, of course, they directed a narrow beam signal straight at us.
This fact about carbon has zero, zip, nada and nothing to do with why it’s the most likely candidate to ge the backbone of a life chemistry. It’s that it readily forms complex, long-chain molecules.
What it comes to, in many ways, is a logical extension of the Copernican Principle: “There’s nothing special about our time or place.” We (well, Western society) have seen our ideas steadily move from a universe centered on the Earth to recognizing that not only is the Earth not the center of the Solar System, but the Sun isn’t the center of the galaxy and the universe doesn’t have a center at all. Using that same logic, the most consistent outlook is that our very existence isn’t special, either.
Also, while it’s taken half of our star’s lifetime to get where we are today, the rest of the universe could hypothetically have had a 10 billion year head start on us. There are good arguments for why life would have been very difficult in the universe for quite some time, as it took a while for an appreciable amount of planet-forming elements to be made, but I don’t know of any scientific reason Earth-like planets around Sun-like stars couldn’t have been forming for 100 million years before we did, if not more. How much further along would we be (if we don’t wipe ourselves out by some means or another) if we had another 100 million years?
There’s no evidence for other life, but given the information we have now and the general outlook astronomy has evolved over the last few centuries, the general consensus is that it’s probably out there even if we can never contact it.
>The set of primes is infinite in size, but there’s only one that’s divisible by two.
I think this is a tautology that is ill-applied to the question at hand. Every prime is divisible by itself. So, there’s one prime that’s divisible by 5, as well. Similarly, there is only one civilization in the universe that is us right now. You’re creating a sort of identity function and using it to demonstrate something unwarranted about infinities. Though, I could use a little more rigor and confidence in this…
But, the probability that a star will have an intelligent civilization living around it is nonzero, which we demonstrate. And if there are infinitely many stars in the universe there have to be infinitely many civilizations.
Modern cosmology seems to show the universe is infinite. We have changed our minds about such things before, so it might be best to maintain a sense of humor about this one too. Less than 100 years ago we thought the universe was the Milky Way, and a great void beyond it, before we realized that other galaxies were other, well, galaxies. But, infinite is infinite, and an infinity of nonzero probabilities is a certainty.
