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A Lonely Universe

inference-review.com

11–20 of 210 posts

Re: A Lonely Universe

#11
post #7

Dumb physics question: If a dying civilization 99,000 light years away sent its last radio transmission 100,000 years ago, we'd never know it happened, right? Maybe I'm missing something with those radio waves bouncing back and forth around us off of various big objects in the milky way.

Correct. We would not know.

Re: A Lonely Universe

#12
post #5

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

Actually, the universe might be too young for life, and we're one of the first. The further you go back in time the more violent events like supernovas you'd find which would make the universe a very hostile environment for life.

I think this is likely.

Always remember that intergalactic travel is exponentially harder than interstellar travel and that is already brutally hard. We need only be among the first in our galaxy to explain the Fermi paradox.

Re: A Lonely Universe

#13
On top of all these probabilities I think you also have to add the probability of high technology. Humans existed for 100k years before we started doing things like harnessing steam and electricity and we have no evidence early humans were insufficiently intelligent. There is a whole chain of mental and cultural developments that may very well not be common.

Re: A Lonely Universe

#14

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

> Personally I think just the fact the universe hasn't been eaten by Von Neumann machines means we're alone. Or maybe it'd make sense to consider how big the Universe is, how fast it expands and combine it with how very local is our perception of it. If you do that and account for how young our capabilities to hear and see stuff out there actually are, Fermi's paradox doesn't make any sense just like the certainty of…

The fermi paradox makes sense within "just" the milky way, so the size of the entire observable universe or the speed it expands doesn't seem relevant.

Re: A Lonely Universe

#15
post #6

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

Is it not possible that colonizing a galaxy is simply too hard, no matter what intelligence?

Exactly. For an optimist, we might one day colonize Mars. Next, getting out of our solar system is incredibly unlikely as the first habitable destination in our own galaxy is just so far away.

Say we stretch our optimism and do make it. Now the colonization of the Milky Way starts. It's a 100,000 light years to the other end. You'd be a completely different species by the time you arrive. Say you achieve that (you won't), now we need some type of coordination and communication. Suck badly though that messages have a delay of 100.000 years. There is no such thing as the human species if we spread out as the delay between even closest habitable zones would be so large that orchestration is impossible.

And we're still within the bounds of a single galaxy, not even intergalactic travel. It simply can't be done. We'll never even escape the solar system.

Long before that would even become a question, it's questionable whether our species continues to exist in its current form. Human level AI is at the horizon within our lifetime. And will then accelerate away. Add a few centuries to that and it's strange to assume we'll still be there, unchanged, as primates controlling a machine a billion times more intelligent. The only path would be to become a machine instead, slowly replacing biological parts with superior silicone. Until nothing biological remains.

Sounds crazy or unlikely? The idea that we remain as-is is far crazier.

Re: A Lonely Universe

#16
Fun! But if abiogenesis happened more than once, and we don't see any alternate-root lineages, then we've admitted the possibility that major advances towards complex life can have a resource lock out effect leading to the extinction of alternates; this could apply to any or all of the critical steps towards technological intelligence.

e.g. did the evolution of homo sapiens and its subsequent monopolization of earth resources decrease the chances of another intelligent species evolving? Probably.

maybe eukaryoticity and sexual reproduction are also advantages so great they confer world domination to their lineages, and therefore will exhibit this kind of founder effect.

Once a world-dominating feature evolves, the rest of the tree must produce a competitor before resources are exhausted, otherwise the feature will only appear once in present lineages. It'd be interesting to know what effects modelling this might have on the resolved probabilities. Seems like the time-to-takeover/time-to-evolve ratio would be the critical factor.

The thought experiment would be: if you took away all the life with feature X, how long would it take to re-evolve that feature?

It might seem like Earth's resources are so vast that they couldn't possibly be 'taken over' in a meaningful way, but consider that all life is competing for a very narrow window of mineral availability, pH, and temperature, and that straying from these consensus boundaries requires you to evolve a huge amount of technology to begin using energy. Also recall that life tends to reproduce conditions suitable for its own continuance. So the result would be, that if you evolve something cool like a mitochondria, you might be able to replace your ancestors in every currently exploitable niche with significant energy flow in fairly short order.

Re: A Lonely Universe

#17
post #13

On top of all these probabilities I think you also have to add the probability of high technology. Humans existed for 100k years before we started doing things like harnessing steam and electricity and we have no evidence early humans were insufficiently intelligent. There is a whole chain of mental and cultural developments that may very well not be common.

well we were having a real bad ice age for most of that time. We pretty much got busy immediate after shit thawed

Re: A Lonely Universe

#18

See also The Dark Forest: > The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life—another hunter, an angel or a demon, a delicat…

I really enjoyed the Dark Forest. The ending felt like the first time I saw The Usual Suspects.

Another alternative hypothesis could be that the universe / even the galaxy is just too big to settle. Any civilization going out would take centuries to cross to other spaces, and completely lose touch with those members which stayed behind. It's hard to have a galactic "empire" when it takes centuries to send resources/soldiers to other worlds. The nearest planet to us, New Horizons, would take nearly 7 hours just to send a message at the speed of light!

The logical thing to do would be to send out machines to mine for resources and send them back and the machines may not be that interested in other lifeforms, other than possibly avoiding them.

Re: A Lonely Universe

#19
post #5

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

Actually, the universe might be too young for life, and we're one of the first. The further you go back in time the more violent events like supernovas you'd find which would make the universe a very hostile environment for life.

A galaxy is really a pretty dangerous place for organic life.

One supermassive black hole merger in the same or nearby galaxy, a biggish black hole merger within 10,000 light years, a magnetar hiccup within 500 ly, or a workaday supernova 5 ly off might be enough to sterilize a whole solar system. There is no guessing how many times life has been wiped clean that way.

The sooner our descendants can get the hell out of the galaxy, the better.

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