Have we reached the point when it is kooky to not believe in massive amounts of intelligent life having evolved throughout the universe?

Great Debates
1

Pre-Webb, We estimated there were hundreds of billions of visible galaxies out there, with each galaxy being made of hundreds of billions of stars and possibly trillions of wet rocks like our little planet earth here. To put such mind-boggling numbers into context: If we named planets after each of the 7 billion living humans today, you and me would each get several trillion solar systems bearing our name. Thousands of galaxies per person. :exploding_head:

Since those numbers are still incomprehensible, more context: If we could magically teleport to each of the solar systems bearing our names, and spend the day looking at each planet for an hour or two, we would die of old age after about 30,000 solar systems, which can be rounded down to 0 compared to the amount of planets we would leave ‘hanging’.

To finish exploring, we would need to somehow live around a billion human lifetimes. All of humanity’s existence is about 40000 lifetimes, put end to end. So we would need to live one million times more than the entire species has lived to have a superficial knowledge of the entire universe. To remember them all, our brain would need Billions of times more memory cells than an average human has. In other words, it would require the entire planet’s human brains to all merge into a mega-brain to remember our space adventures.

If the odds of winning the powerball jackpot are almost 1 in 300 million, then the probability of humans being the only intelligent species is roughly equivalent to winning all of the world’s lotteries on the same day. It appears the Webb telescope’s more detailed picture is showing these already staggering numbers were under-counts by at least one order of magnitude, maybe more. Stable galaxies, now seen in infrared, formed significantly earlier than expected.

I should note there is an upward trend in the numbers of galaxies every time we look with a bigger, better, sharper or infra-redder telescope. Maybe we’re still underestimating the number of galaxies out theres. So, taking all of this into account:

Can we finally agree that, not only is it logical to believe there are probably billions of different species that have evolved and will evolve long after we are dead, but to think we are alone in the universe is utterly kooky?

2

Do you know what the odds are of intelligent life emerging?

3

Yeah, that’s my question. I’ll grant that there are a helluvalot of planets in the universe, but I don’t know what it takes, or how unlikely it is, for intelligent life to appear on any of them. So I remain agnostic as to whether intelligent life exists elsewhere in the universe.

4

I’ve often thought that believing we’re the only sentient life in the universe is pretty much the height of arrogance- heck, we’ve got several other species here on Earth which are pretty darn close. Furthermore, we’ve found life on Earth almost everywhere we’ve looked. So yeah, given the massive size of the universe, there’s pretty much got to be other life out there, and if even only a small fraction of that life is sentient, that’s still billions, if not trillions, of alien intelligences out there.

So, uh, where are they?

Beats me.

I’ve often thought that the anthropic principle can give us a explanation for why we haven’t already encountered other intelligences, if not the mechanism. If an intelligent, expansive species had evolved anywhere in our cosmic neighborhood even just a million years before us, they’d already be here and would have out-competed us for resources- our evolution would have turned out entirely differently, if at all. So, we’re only here to wonder why we’re alone because we are alone.

Either something goes through and periodically culls life in the universe to keep it from expanding (and we’re just lucky enough to have evolved right at the end of a culling), or intelligence is an evolutionary dead end- any civilization will kill itself off long before it can expand to neighboring stars.

5

Well, we should so agree, but apparently we don’t. Personally I agree that it’s “kooky” to believe that we’re alone in the universe.

I don’t subscribe to either the weak, strong, or the so-called “participatory” anthropic principles. What I do observe is that the history of the universe is a history of fundamental particles forming composite particles, and those forming atoms, and then molecules, and some of those molecules forming organic compounds. It appears to be thus all over. We also observe – though so far only on Earth – those organic compounds forming increasing complex self-replicating entities that we eventually call “life”.

The idea that this one planet, orbiting around an ordinary star in the somewhat distant fringes of a commonplace spiral galaxy which itself contains billions of stars and resides among billions of other galaxies, is somehow miraculously unique is just a perversion of logic.

6

I’d say it merely acknowledges the fact that we don’t know how common intelligence is.

Earth has had life on it for nearly 4 billion years, perhaps longer. Complex cells (eukaryotes) have been here for 2 billion years. Multicellular life for 1 billion. Animals for 600 million. Yet intelligence/sentience appears to have emerged only once, less than 250k years ago. Given the wide variety of complex animal species the earth has seen come and go, it seems intelligence is a scarce commodity.

But earth’s the only example we have. Maybe it occurs more often elsewhere. But maybe not.

I think it’s a sure bet that there’s life elsewhere. And I’d bet on intelligent life somewhere else too, given just how many damn galaxies there are out there. But it’s not kooky to reserve judgement on the issue, given what the (grantedly very scant) data we have on the subject points toward so far.

7

IMO there’s no meaningful difference between “there is no intelligent life elsewhere” and “there probably is but it’s so far away we’ll never become aware of each other”.

8

I disagree that we’ve reached a point.

The so-called Fermi Paradox, which asks why if the universe is teeming with life we haven’t seen away, dates from 1950. It’s been talked about a million times every year since. Anybody with the slightest interest in astronomy knew long before then about the gigantic number of stars and presumed gigantic number of planets in the galaxy and universe.

The numbers may have become larger and more widely known since, but nothing fundamental has changed at all. It still seems reasonable that other intelligent life has existed or does now, but there still remains exactly zero evidence.

Moreover, we now know far more about the origins of life than we did then and about how many improbabilities must have intervened between its origin and our existence. The odds on our sapience are one in a number so large that the number of possible planets is a comparative trifle. Logically and reasonably, we should be less positive of the existence of intelligent life elsewhere than we once were.

That’s the real paradox today. Our knowledge of both sides of the coin has increased tremendously and both seem to be better bets. Yet both cannot be true.

The only non-kooky stance is to wait.

9

Yes, then shouldn’t it be a continuing process that we can observe.

10

As fas as I am concerned, the only really kooky thing is that camera from Ideal https://upload.wikimedia.org/wikipedia/commons/thumb/6/61/Kookie_Kamera_(2167840750).jpg/457px-Kookie_Kamera_(2167840750).jpg?20151225204653

11

Nuts. Here’s the real Kookie.

12

I think there’s almost certainly life throughout the universe. On earth, life seemed to appear pretty much as soon as conditions made it even slightly possible. Further, life reaches even the harshest environments on earth. There must be billions upon billions of planets that at some point had at least slightly earthlike conditions, and even if only a small fraction have life, that would be tons of planets with life.

But intelligence, at least the type that can develop advanced technology, appears to only have involved once on earth. So we can’t know if it was inevitable, a fluke, or something else. So there’s no way to know, at this time, whether intelligence is common in the universe.

13

People will often go off, like the OP did, and breathlessly exclaim, “Oh! There must be quadrillions upon quadrillions of Earthlike planets in the entire universe! There thus MUST be intelligent life on at least a few! The odds strongly suggest it!!”

Except that you do NOT know the odds, at all. They could very well be a googol orders of magnitude beyond the number of potentially inhabitable planets. I’m not sure what the exact fallacy here would be called (Argument From Incredulity?), but the point is, no matter what number crosses your personal incredulity threshold, the actual odds may likely be much longer than that.

And the Weak Anthropic Principle (at least)) is perfectly on point, because the putative aliens in question would NOT logically benefit from riding on our anthropic coattails. My informed opinion is that the number of hurdles which must be successfully jumped (aka filters) is legion. Fall down on just one, and no technological civilization.

14

I do agree. Wholeheartedly.

But others won’t.

15

I’m in the “of course there’s other life out there but we will never contact it” camp. Soon, probably with the JWST in the next few years, we will detect planets that are very likely to contain organic compounds that only life can produce. Bam! We are not alone in the universe. Will that change anything? No. Will we ever find a way to deal with the absurdly far distances involved in space travel? No. Will another alien species? Maybe. Maybe some sentient trees will build ships that ply the stars and shrug off the eons it takes to do so. But we’ll never know.

16

Aside from the good points above, do not overestimate our ability to detect other intelligences, or overestimate their ability to detect us.

Technosignatures of civilization have only been showing up in our atmosphere for a couple hundred years. That means that any civilization beyond 200 light years or so would have no idea we exist, and therefore would not be beaming a signal at us. If we want to detect leakage from other communications or omnidirectional transmissions (say they are just broadcasting ‘here we are’ to the universe), we would have to aim our biggest dishes at them to have a chance of hearing it, and it would have to be probably no more than 10 or 20 light years away. Now we’re talking about on the order of ~100 star systems.

Also, we have in fact evolved high intelligence on the planet multiple times. Cetaceans, primates, maybe cephalopods and some birds are very intelligent. But it’s also clear that there are many ways intelligence can manifest, and the only one that led to a technological civilization is us.

If a civilization developed in an ocean, they might never know about the stars or think of exploring them. If a civilization developed on a world with twice our gravity, they might never be able to get rockets into space. If it developed underground, or in a world with resources such that manipulable hands aren’t necessary or helpful, they might remain like dolphins - smart but utterly incapable of advanced tech. Or perhaps the most common intelligence is a hive mind that can’t move off its planet. Or there is some other common configuration of advanced life that we simply don’t know about. We are infants when it comes to the universe.

If we hadn’t been hit by a big asteroid 70 million years ago, it’s possible that dinosaurs would have ruled for another 500 million years and intelligent technological life would never have evolved.

If the Great Oxygenation event had not happened, Earth might have remained a place where only low-energy bacteria or other simple life exists.

Here’s the good news: Radio SETI was always a longshot based on a lot of assumptions. But now we have the capacity to just go look at exoplanets for signs of life with JWST and other advanced telescoppes. The chance of us finding life in the next decade is much higher than it’s been in the past. And if we don’t, we will have sampled enough atmospheres of exoplanets to really constrain some of the terms in the Drake equation.

Maybe we’ll look at several hundred exoplanet atmospheres and realize that we hit some exceedingly rare goldilocks combination on Earth. Maybe every other earth-style planet we find will be a hellscape like Venus or some other horrible configuration.

If there are civilizations in other galaxies, up to this point we have had zero chance of detecting them. So we should really limit ourselves not just to our galaxy, but probably to at most the region of our galaxy that is not blocked by the center or too far away. Realistically, probably no more than a few thousand light years. That’s still hundreds of millions of stars, but that’s at least a small enough number that it’s possible that the odds are against another civilization existing at the same time ours is.

The last point is also important. We have no idea how long a technological civilization might last. If it’s short enough, we could have had a million civilizations in our galaxy without one ever overlapping another in time. We might find that the galaxy is a giant graveyard, with dead civilizations outnumbering live ones by 10,000:1.

Or, there is something about the universe we do not understand that either limits civilization development or our ability to find it. Recency bias has us always assuming we understand far more than we do about how things work. Astronomers thought they had a pretty good handle on how the universe worked 60 years ago. Then we discovered dark matter and dark energy and all kinds of stuff we had no idea about. We had no idea quantum mechanics was a thing 110 years ago. To think that we’ve NOW got most of it figured out after a blink of an eye of time is pretty hubristic. Maybe signatures of civilizations are all around, but we don’t have the understanding or technology to recognize them yet.

But it’s all speculation. Without evidence, all we can say scientifically is, “We don’t know.”

17

Side note: What fascinates me is how many false starts there were even then. How many hominid species developed, more intelligent than apes, but unable to go that last mile to full sapience? New ones seem to be discovered from time to time. They all lacked – something – until Homo Sapiens came along. That there were so many failed attempts leads me to wonder if, well I’m not sure how to put this except anthropomorphically, if nature didn’t want intelligence to emerge.

18

The OP mentioned belief, not knowledge. We’ll never know if any of these galaxies hundreds of millions of light years from us have intelligent life, sure. But that doesn’t mean it isn’t reasonable to believe they do.
Let’s talk about conscious life, not intelligent life, since there are plenty of animals with reasonable degrees of intelligence, but not consciousness (as far as we can tell.) If all species but humans were stone cold dumb, I’d say the odds of other conscious and intelligent life would be low. But we know there is a non-zero chance of an intelligent species becoming intelligent. Sure it took a long time, but there was a reset 67 million years ago or thereabouts.
What mutation enabled consciousness? When we find that out we’ll understand the odds.

19

It’s kooky not to take both major positions articulated in this thread seriously.

On one hand, it’s absolutely true that life on Earth arrived early and quickly filled every available niche, and that even intelligent life doesn’t appear all that uncommon, and that while humans seem to have gotten a little lucky in our bipedal nature, as well as being land-dwellers that can use fire, surely those factors don’t tip the scales by factors of billions.

But on the other hand, there isn’t the tiniest shred of a speck of evidence that life at all exists anywhere but on Earth. Visible universe or otherwise. Life arrived on Earth early, but not that early–not enough to really draw conclusions from. It could just be that the odds of life appearing on some planet really were one in a googol and we’re here to see it. It’s also slightly concerning that all life on Earth shares a common ancestor. Maybe DNA/RNA/etc. life just outcompeted the competition… but that didn’t happen anywhere else in the tree of life. Prokaryotes and eukaryotes still compete, as do monocellular and multicellular life, and so on. Surely, DNA isn’t the superior molecule in every possible niche. And yet that’s what we’ve got. Maybe even life on Earth was extremely unlikely.

If we find life elsewhere in the solar system, especially with a different chemical basis, that dramatically tips the scales. As would direct evidence among the stars. But until that happens, we have no choice but to remain in a quantum superposition of “there’s no evidence at all” vs. “it’s arrogant to think we’re the only ones”.

20

Yeah, I think “belief” itself is inappropriate in this case. What we have is a situation in which there is an intedeterminate probability of extraterrestrial sentient life, but no proof that it exists. I personally would just leave it at that and avoid believing in any unproven conclusion.