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Dissolving the Fermi Paradox

arxiv.org

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Re: Dissolving the Fermi Paradox

#81

Post by jessriedel »

gwern wrote: post #70
jessriedel wrote: post #60

Earlier quoted context omitted.

I don't understand. Your point ("even small amounts of uncertainty ... a large mean number of ETIs?") sounds just like a rephrasing of his ("We don't know the parameters well, it's within our margin of error that no one else is out there"). In particular, how could your statement be false while his be true?

His point, as suggested by the comments agreeing with him and the claims that it's 'obvious', is that the parameters could be small. The problem with that is the parameters look large. Adopting a distribution and calculating it out gives much broader predictive distributions. You can have all the parameters not be that small but small enough, combined with minimal uncertainty, that on many draws from the posteriors,…

I asked how his statement could be true while your statement could be false (which would show that even if his statement was granted then your statement could be new and non-obvious). You replied by claiming that his statement isn't justified while your statement is. This is a formalization of an intuitive argument, not a surprising dissolution of a paradox.

In other words, if other researchers had considered his statement and dismissed it without doing the sort of analysis being formally written up in this paper, then those dismissive researchers would have been making a mistake.

As I said elsewhere, I think these sorts of formalizations are really very helpful. Perhaps, given the sloppy thinking in this area, even more helpful than novel results. I generally think review articles are distillation is vastly undersupplied

Re: Dissolving the Fermi Paradox

#82

Post by jobigoud »

gmuslera wrote: post #75

The reasoning seem to be "as we don't have enough data, lets conclude whatever I want". The Fermi paradox assumes that if there are aliens more advanced than us somewhere for a long time, they should be here by now. Maybe more advanced technology enables interstellar travel (maybe not, maybe is not practical at all), maybe they may not have all our motivations (expansion, technological advancement in our own focus, e…

When talking about the Fermi Paradox it's not about what this or that extra-terrestrial civilization might do. It's about what none of them is doing.

When you say "maybe they don't want to expand", if you want this to explain the paradox, you actually mean "none of them want to expand". Because if just one did, we would see it.

Re: Dissolving the Fermi Paradox

#83

Post by jobigoud »

btilly wrote: post #80

I have trouble calling it a paradox, because there is nothing that needs explaining in my view. Just throw in the fact that known fudge factors are important, and throw in the fact that there are more fudge factors that we don't know. For example the traditional Drake equation doesn't include as a major factor "large moon that stabilizes the axial tilt over evolutionary time". And yet that seems to be needed and at l…

It doesn't have to include these specifics. They are just sub-factors contributing to higher level factors.

Your first is covered by "fl, the fraction of those planets that actually develop life", and your second is covered by "fi, the fraction of planets bearing life on which intelligent, civilized life, has developed".

What you are saying seems to be the same as OP. It's not a paradox because the chances are insignificant, so we are indeed alone.

Re: Dissolving the Fermi Paradox

#84

Post by greglindahl »

TeMPOraL wrote: post #58
jandrese wrote: post #46

Earlier quoted context omitted.

The Drake equation is the epitome of garbage in garbage out. Trying to draw a line using a single data point. There was recent news from NASA about the discovery of organic molecules on Mars and the possibility of life there at some point in the past. Discovery that life once existed on Mars would blow up the assumptions in the Drake equation. As for the Fermi paradox I'm still of the opinion that its solution is sim…

Also, VR. I already fear the future of humanity is not exploring strange new worlds, but creating virtual ones, and converting the solar system into more computronium. (And the weird thing about that is that I feel it's a bad thing for some reason, but I can't articulate a coherent argument against it.)

There are a bunch of scifi novels that explore the issue, and most of them feature bad things that result.

Re: Dissolving the Fermi Paradox

#85

Post by jackconnor »

I feel like if aliens come they might keep themselves hidden, rather than announce their presence. If so, it could be Fermi was right, we just haven't seen the evidence of it yet, since the Fermi Paradox presupposes that their should be intelligent life and the we actually can point to evidence of it.

Re: Dissolving the Fermi Paradox

#86

Post by mechsquirrel »

gmuslera wrote: post #75

The reasoning seem to be "as we don't have enough data, lets conclude whatever I want". The Fermi paradox assumes that if there are aliens more advanced than us somewhere for a long time, they should be here by now. Maybe more advanced technology enables interstellar travel (maybe not, maybe is not practical at all), maybe they may not have all our motivations (expansion, technological advancement in our own focus, e…

The thesis of the article is not "lets conclude whatever I want"

The foundational assumption is that (a) historically people have just picked the values for the Drake Equation that "felt right", and this is wrong, biased, and stupid, and (b) we should not be surprised if the Drake parameters fall in any order of magnitude. So let's Monte Carlo in a log-scaled distribution (roughly). Thus, given what we actually do know, median civilizations per galaxy is 0.32, average is 27 million.

Interestingly, this suggests that optimistic Drake Equation parameters must be wrong, lest they create an empirically impossibly-populated galaxy.

Re: Dissolving the Fermi Paradox

#87

Post by jobigoud »

transfire wrote: post #3

"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." There is no way we are alone.

The Universe is old. Really old.

Re: Dissolving the Fermi Paradox

#88

Post by jobigoud »

mirimir wrote: post #65
nervousvarun wrote: post #52

Earlier quoted context omitted.

Just curious how can anyone conclusively claim life arose only once? Don't they just say we only have evidence that it arose once? Maybe it started twice or 100M times but 100% of those times the newly started life was "consumed" in some way by already existing life etc.

Yes, that seems a dubious claim. There's no way to know, except though simulations, how many dead ends there were. What we know is that all existing organisms share basic biochemical features. More or less the same nucleic acids, amino acids, and so on. So other paths arguably got competed out. Or merged, as we know for nuclei, mitochondria and chloroplasts in eukaryotes. Probably also components of bacteria. Flagell…

It's also because we have tried all sorts of approaches for the past 70 years or so and we haven't been able to bootstrap it ourselves.

Re: Dissolving the Fermi Paradox

#89

Post by mirimir »

jobigoud wrote: post #88
mirimir wrote: post #65

Earlier quoted context omitted.

Yes, that seems a dubious claim. There's no way to know, except though simulations, how many dead ends there were. What we know is that all existing organisms share basic biochemical features. More or less the same nucleic acids, amino acids, and so on. So other paths arguably got competed out. Or merged, as we know for nuclei, mitochondria and chloroplasts in eukaryotes. Probably also components of bacteria. Flagell…

It's also because we have tried all sorts of approaches for the past 70 years or so and we haven't been able to bootstrap it ourselves.

I doubt that any of the experiments have run for longer than a few years. And probably less.

Re: Dissolving the Fermi Paradox

#90

Post by bena »

jandrese wrote: post #68
jcranmer wrote: post #63

Earlier quoted context omitted.

Only two variables of the Drake equation can be meaningfully estimated: rate of star formation and fraction of stars with planets. The number of life-supporting planets per star is surprisingly ill-defined (what number is that for Sol?). All of the other variables are basically knobs that let you control what you want the answer to be. > There was recent news from NASA about the discovery of organic molecules on Mars…

It doesn't help that we have a giant noise source in the middle of our solar system that shoots the noise floor through the roof when you're trying to detect laser comms over light years. Plus, even at lightspeed you're talking multi-year roundtrips to our nearest interstellar neighbors. Our entire history of radio emissions has only made it to around 500 solar systems currently. Even if someone was listening and res…

> Plus, even at lightspeed you're talking multi-year roundtrips to our nearest interstellar neighbors.

That's something I think people ignore. It takes 4 years to get to the next closest star at the fastest possible speed.

And that's ignoring all of the other issues with long term space travel. 4 years. To a place where we're relatively certain doesn't have life capable of technology.

The assumption that other intelligent life will conveniently find a way around the speed of light is a big one.

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