The Fermi Paradox, Percolation, and Inbreeding • Hacker News Board

Re: The Fermi Paradox, Percolation, and Inbreeding

#51

Post by pigpop » Sun, Jul 19, 2026, 12:01 AM UTC

bryanrasmussen wrote: post #49

pigpop wrote: post #45

The corruption of the Fermi Paradox is a personal bugaboo of mine. Somewhere along the way everyone started getting it completely wrong, interpreting it as being about galactic colonization and the spread of intelligent life throughout the galaxy. I don't know where this came from but I deeply wish people would stop calling it the Fermi Paradox and give it its own name. Fermi's contention of "where are they?" was pre…

You are wrong. First, I would just naturally assume you are wrong as Fermi would have known that FTL was practically impossible. Fermi evidently made the comment in the 1950s at Los Alamos, as I understand it became widely known due to Carl Sagan's 1963 paper "Direct contact among galactic civilizations by relativistic interstellar spaceflight" https://www.sciencedirect.com/science/article/abs/pii/003206... What the…

"I have a vague recollection, which may not be accurate, that we talked about flying saucers and the obvious statement that the flying saucers are not real. I also remember that Fermi explicitly raised the question, and I think he directed it at me, ‘Edward, what do you think? How probable is it that within the next ten years we shall have clear evidence of a material object moving faster than light?’ I remember that my answer was’ 10–6.’ Fermi said, ‘This is much too low, The probability is more like ten percent’(the well known figure for a Fermi miracle.)”[0] --Edward Teller

"York believes that Fermi was somewhat more expansive and 1‘followed up with a series of calculations on the probability of earthlike planets, the probability of life given an earth, the probability of humans given life, the likely rise and duration of high technology, and so on. He concluded on the basis of such calculations that we ought to have been visited long ago and many times over. As 1 recall, he went on to conclude that the reason we hadn’t been visited might be that interstellar flight is impossible, or, if it is possible, always judged to be not worth the effort, or technological civilization doesn’t last long enough for it to happen. ” York confessed to being hazy about these last remarks."[0]

The recollection of the conversation by all the parties present is fragmentary and disagrees on exactly what was discussed but the gist of it appears to be about the feasibility of interstellar travel, not colonization or percolation or whatever you want to call it. The whole question of "where are they" doesn't make much sense when you think of it in terms of one off events such as permanent settlement of a planet using generation ships or other feasible means of slower than light travel simply because you would always miss each other in time. Either we wouldn't be here because they settled Earth first and interrupted our development or they're not going to show up for another million years.

I'm not contending that Fermi necessarily believed that the theory of relativity was wrong or incomplete but that the essence of the Fermi Paradox is that either interstellar travel is impossible due to distance + time required or there is some way to overcome the restrictions of distance + time which during this informal discussion over lunch seems to have supposed faster than light travel as the solution. Based on the recollected pieces of the conversation I'm pretty sure Fermi's napkin math didn't involve fudging the likely duration of a technological civilization up to millions of years, the likelihood of that happening is certainly less than Einstein's theory being incomplete.

Honestly, the argument as it is proposed today should be attributed to Hart since it conforms exactly with what he proposes so from now on I'm going to call this form the Hart Paradox.

[0] https://upload.wikimedia.org/wikipedia/commons/5/54/%22Where...

Re: The Fermi Paradox, Percolation, and Inbreeding

#52

Post by jacobgold » Sun, Jul 19, 2026, 1:00 AM UTC

pigpop wrote: post #50

jacobgold wrote: post #30

Earlier quoted context omitted.

Of course humanity is not immune, but it is resilient. Even if 99.99% of people died from an asteroid, it might only take a few hundred (or thousand) years to rebuild the population and the world. And once humans live on multiple planets, which is likely within 100 years, the odds of permanent extinction become remote.

Brother, it takes several hundred years to recover from a political collapse of a civilization. A few thousand is in the ballpark for a 90% reduction in population coincident with a similar loss in knowledge. A 99.99% reduction would be more like tens of thousands of years. It's not just that we need to have people living on another planet, we need a fully self-sufficient civilization on another planet which is at le…

You can make up your own numbers for the timeline.

Life is still likely (not guaranteed) to escape Earth one way or another, however long it takes and however many attempts it takes.

Re: The Fermi Paradox, Percolation, and Inbreeding

#53

Post by sameerds » Sun, Jul 19, 2026, 1:46 AM UTC

Nevermark wrote: post #22

> Furthermore, light-speed lag and distance mean that child civilizations must be functionally independent of parent cultures. Makes me wonder if a solar system wide civilization, with trillions of beings, wouldn't invest in ships to go to the next system, extract resources, and create a stream of resources ships going back to the original solar system. That might sound uneconomical. Why not just go to the other syst…

> Makes me wonder if a solar system wide civilization, with trillions of beings, wouldn't invest in ships to go to the next system, extract resources, and create a stream of resources ships going back to the original solar system.

You mean colonize and feed the empire?

Re: The Fermi Paradox, Percolation, and Inbreeding

#54

Post by sfn42 » Sun, Jul 19, 2026, 3:20 AM UTC

jacobgold wrote: post #35

sfn42 wrote: post #28

Earlier quoted context omitted.

I imagine that 100 years from now(or significantly less than that) the ocean water level will be several meters higher, large parts of the world will be unliveable due to heat waves and wars will be fought over food and water. I doubt our species will last another 1000.

You might try spending some time reading predictions of doom and gloom from the past. It should be very reassuring.

In not talking about baseless predictions. I'm talking about science. This is not speculation, it's not a possible future scenario, this is the world we currently live in and the trajectory we know for a fact that it is taking. We're setting heat records literally every year. All over the world. The polar ice caps, Greenland etc are melting rapidly, this is not speculation these are facts, these are things currently happening.

We know how much ice is on land, people have spent decades drilling the ice and calculating it's volume etc, we know it's melting because there's way less of it now than there was just decades ago and we know how much that melted ice will influence water levels.

We know the effect greenhouse gases have on the atmosphere and global temperatures, people have made scientifically informed charts predicting how the temperature will rise decades ago and we are right on track.

The prediction happened when I was a child, and all my life I've watched the prediction come true. The fact that there's still millions if not billions of people out there who are living through the same situation and still think climate change is a hoax is absolutely baffling to me. Just look at a fucking global average temperature chart for the past few decades holy shit man it's not a secret the planet is cooking. It's not maybe going to cook 500 years from now it's cooking right now and it's getting worse every year how can you possibly look at these simple clear facts and not understand that it's going to continue?

You guys annoy me so much holy shit open your eyes and just look at the world we live in

Re: The Fermi Paradox, Percolation, and Inbreeding

#55

Post by Balgair » Sun, Jul 19, 2026, 3:21 AM UTC

Related: the reverse Fermi Paradox.

Essentially, we've been humans for about 200,000 years. But only in the last 5,000ish years have we done the whole civilization thing. Why?

Climate has a lot to do with it, we know that, but about 195,000 years is a lot of time too.

Quite the mystery.

Re: The Fermi Paradox, Percolation, and Inbreeding

#56

Post by sfn42 » Sun, Jul 19, 2026, 3:31 AM UTC

qayxc wrote: post #36

sfn42 wrote: post #28

Earlier quoted context omitted.

I imagine that 100 years from now(or significantly less than that) the ocean water level will be several meters higher, large parts of the world will be unliveable due to heat waves and wars will be fought over food and water. I doubt our species will last another 1000.

I'm very confident our species will last longer than the next 1000 years. Our current civilisation, though, now that's a completely different story.

Yeah if we're back to sticks and stones we might as well be extinct as far as I'm concerned.

Re: The Fermi Paradox, Percolation, and Inbreeding

#57

Post by yogthos » Sun, Jul 19, 2026, 3:44 AM UTC

NitpickLawyer wrote: post #38

yogthos wrote: post #8

The assumption that biological life will be doing galactic colonization seems myopic in the extreme. Let's just consider the progression here. Life on Earth appears around 4.5 billion years ago. Humans start evolving around 2.8 million years ago. Use of language appears around 100,000 years ago. Writing is invented around 5500 years ago. Inventions of language and writing are the landmark moment here. Before language…

> For all we know the Universe may be teeming with intelligent life and we just don’t recognize it as such. This is my preferred answer to the Fermi question as well. Unless two civilisations are in a precise (and likely small) window where they both can and want to communicate, it's likely the less advanced one wouldn't even recognise the other one. Especially if the other one doesn't "want" to be recognised.

Yup, and just look at how difficult it is for us to recognize different kinds of intelligence on our own planet too. We've just started figuring out that animals like crows have complex cognition.

Re: The Fermi Paradox, Percolation, and Inbreeding

#58

Post by jacobgold » Sun, Jul 19, 2026, 3:52 AM UTC

pigpop wrote: post #47

jacobgold wrote: post #17

Earlier quoted context omitted.

That seems unlikely. Just imagine humanity 100, 1000, and 1,000,000 years from now. Humans will have solved every physical problem that is solvable. Humans will have also evolved into new kinds of immortal/superintelligent beings that would be totally unrecognizable to us. It may be the case once a civilization reaches "max level" they universally decide to "reset the game" because there's nothing left to do. Maybe s…

No cohesive civilization on earth has been able to continue uninterrupted for 1000 years, our chances aren't as good as you think they are especially since our current civilization is showing all of the signs of being over the hill and accelerating in its decline. Technological advances can be lost and the capacity of a civilization to accomplish far reaching goals can stall and degrade and eventually cease all toget…

> No cohesive civilization on earth has been able to continue uninterrupted for 1000 years...

Not sure what your definition of "cohesive" is but we've had our civilization going for ~5000 years with only regional setbacks.

Re: The Fermi Paradox, Percolation, and Inbreeding

#59

Post by jacobgold » Sun, Jul 19, 2026, 4:03 AM UTC

sfn42 wrote: post #54

jacobgold wrote: post #35

Earlier quoted context omitted.

You might try spending some time reading predictions of doom and gloom from the past. It should be very reassuring.

In not talking about baseless predictions. I'm talking about science. This is not speculation, it's not a possible future scenario, this is the world we currently live in and the trajectory we know for a fact that it is taking. We're setting heat records literally every year. All over the world. The polar ice caps, Greenland etc are melting rapidly, this is not speculation these are facts, these are things currently…

Greenhouse gas emissions are a huge problem, but there's no reason to believe we can't solve or mitigate the effects one way or another. It may come at a terrible cost, or it may turn out to be easier than you'd expect.

You're not using "science" to predict the future. You're just expressing a pessimistic belief that we're doomed based your own idea of how things will play out.

To me, optimism seems far more justified based on our track record, we've more-or-less solved some big problems:

- "Population growth is going to cause worldwide famine"

- "We are going to run out of oil and civilization will collapse"

- "The ozone hole is going to expose everyone to dangerous radiation"

- "Acid rain is going to destroy forests and kill lakes"

- "City air pollution is going to make major cities unlivable"

- and smallpox/polio/HIV/leaded gasoline/etc

Re: The Fermi Paradox, Percolation, and Inbreeding

#60

Post by sfn42 » Sun, Jul 19, 2026, 4:48 AM UTC

jacobgold wrote: post #59

sfn42 wrote: post #54

Earlier quoted context omitted.

In not talking about baseless predictions. I'm talking about science. This is not speculation, it's not a possible future scenario, this is the world we currently live in and the trajectory we know for a fact that it is taking. We're setting heat records literally every year. All over the world. The polar ice caps, Greenland etc are melting rapidly, this is not speculation these are facts, these are things currently…

Greenhouse gas emissions are a huge problem, but there's no reason to believe we can't solve or mitigate the effects one way or another. It may come at a terrible cost, or it may turn out to be easier than you'd expect. You're not using "science" to predict the future. You're just expressing a pessimistic belief that we're doomed based your own idea of how things will play out. To me, optimism seems far more justifie…

The difference between the problems you listed and climate change is that those problems are solvable. That's why we've solved them. They're also not nearly the same scale as climate change which is apocalyptic. You just cherry picked a few things we've solved and ignored the plethora of things we haven't as if that proves anything at all. How about cancer? All the other diseases we can't cure? Most of the world still lives in extreme poverty. Lots of people starve every day. Russia is bombing Ukraine. Meanwhile everyone's bickering about data centers and ram prices.

Climate change is not solvable. There is no solution. The only thing I know of that we might be able to do is spray enormous amounts of aerosols into the atmosphere hoping to block the sunlight. This might backfire spectacularly, also might not even work. It's a hail Mary we'll probably try when things get bad enough.

That's it. That's the only idea we have that might help. Maybe there's others I don't know about, but they're not good or we would be doing them already. Carbon capture is a joke, it will never make a difference. We would need a million carbon capture plants, we can't build a million capture plants.

Even if we completely stopped emitting CO2 today we would be completely fucked, and we're not doing that we are in fact producing more CO2 every year. That will probably change eventually but it's already too late.

Obviously nobody can know for sure, maybe we will get lucky and someone will come up with a genius plan that actually works. But that's far from guaranteed, as far as we know right now it's impossible so just assuming that's going to change is extremely naive. It's a thin sliver of hope it's not what we should be expecting nor relying on.

We have no good solution, and given the scale of the problem we have almost no hope of finding one. Do you understand how much atmosphere there is? We've been burning fossil fuels as fast as we can for centuries, now we are finally seeing the result of that and it's so slow that lots of people still don't believe it's happening. It's way harder to reverse.

Also, ice. Ice is important. Ice reflects sunlight and essentially stores cold. Less ice means more heat. More heat means less ice. Do you understand how long it's taken to build the amount of ice on the planet? Absolutely no amount of terraforming will rebuild the ice we're losing and have lost, not in thousands of years.