The Fermi Paradox • Hacker News Board

Re: The Fermi Paradox

#21

Post by sampo » Thu, Dec 25, 2014, 8:16 PM UTC

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

> until all of a sudden the most distant stars go dim

Why the most distant?

Re: The Fermi Paradox

#22

Post by joe_the_user » Thu, Dec 25, 2014, 8:19 PM UTC

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

I feel there's a language used here to conceal some questionable reasoning;

"Why don't we see a civilizations spanning a galaxy? How would that work? No idea but why don't we see it?"

We could ask why we don't see Lovecraftian gods or giant life forms that each stars. We don't know how that works either.

Re: The Fermi Paradox

#23

Post by _greim_ » Thu, Dec 25, 2014, 8:34 PM UTC

gpsx wrote: post #6

This article does a good job of covering a lot of different ideas on this paradox. I have a problem with the idea of "big numbers" in it though, like where it implies 500 billion billion is nearly infinite, or that one-in-a-billion is a freak occurrence. There is a saying that if enough monkeys pound on a keyboard, one will type Hamlet. This would take a lot of monkeys. If we take the odds of hitting one character to…

We can't calculate the probability of life arising though because even if we did know how it arose here—which we don't exactly—we don't know all the possible different ways it can arise, which may or may not also be a number raised to a large power.

Re: The Fermi Paradox

#24

Post by [deleted] » Thu, Dec 25, 2014, 8:44 PM UTC

[deleted]

Re: The Fermi Paradox

#25

Post by keithnoizu » Thu, Dec 25, 2014, 8:50 PM UTC

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

There is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (meaning our planet was seeded at some point with some primitive life forms that than continued on their evolutionary tracks towards this point in time).

So you have many planets starting to get to the point where space exploration on a wide scale is feasible. Maybe a few are a hundred thousand and some change years ahead or behind us but the likelihood is low that many are significantly well established, or established long enough and close enough for us to detect.

Re: The Fermi Paradox

#26

Post by tnaro » Thu, Dec 25, 2014, 8:51 PM UTC

Pxtl wrote: post #16

ccvannorman wrote: post #4

i love this puzzle. here are some theories: 1. simulation argument 2. civilizations have a high or inevitable chance to self destruct after 3. civilizations transcend our observable universe after 4. due to the single observer problem, humans fail to grok some very important feature of larger scale space that prevents detection/increases isolation [1] http://accelerating.org/articles/transcensionhypothesis.html

4 seems likeliest. Interstellar colonization is simply impossible because of the vastness of the distance that must be covered. It requires more energy than can be summoned to get a useful amount of hardware across multiple lightyears.

well to be fair, purely theoretically, you "just" need to accelerate once (and be able to hit the brakes many many many years later!) and find a way to sustain (food, water, air) yourself on a spaceship. Then a colonization flight might very well take serveral hundred to thousands years in the beginning.

A bit like the general idea of the recently aired tv show Ascension.

Re: The Fermi Paradox

#27

Post by DavidSJ » Thu, Dec 25, 2014, 8:54 PM UTC

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

I had this idea recently myself and to the best of my knowledge you're the only other person who's mentioned it. The closest I've found is the "galactic preemption" hypothesis published in the 80's, but that's more an explanation for why only one civilization would exist in a single galaxy, rather than for why a newborn civilization such as our own would look at the sky and see no signs of civilization in the whole universe.

Have you seen this idea published anywhere?

Re: The Fermi Paradox

#28

Post by DavidSJ » Thu, Dec 25, 2014, 8:57 PM UTC

keithnoizu wrote: post #25

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

There is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (meaning our planet was seeded at some point with some primitive life forms that than continued on their evolutionary tracks towards this point in time). So you have many planets starting to get to the point where space exploration on a wide scale is feasible. M…

There is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (meaning our planet was seeded at some point with some primitive life forms that than continued on their evolutionary tracks towards this point in time).

Interstellar seeding is not required to believe that complex life becomes possible at approximately the same time throughout the universe. Other possible reasons:

- Concentration of heavy elements has increased with successive star generations.

- Galactic cosmic ray bursts (which can sterilize all complex life within thousands of light years) become less common as a galaxy ages.

Re: The Fermi Paradox

#29

Post by nhaehnle » Thu, Dec 25, 2014, 9:13 PM UTC

Xcelerate wrote: post #15

I am surprised a more common argument was not mentioned: other life exists but the laws of physics limit our interaction. Maybe there is undiscovered physics like wormholes or time travel, or maybe there isn't and the speed of light really is a fundamental limit that cannot be surpassed. In that case, no matter how advanced another civilization becomes, they still can't violate natural law and are thus unable to reac…

I often wonder this as well. The speed of light isn't really a physical limit to expansion - generation ships are theoretically possible. It may just be that the Great Filter takes the form of relatively benign[1] economic and/or sociological obstacles.

At least, if you take a diff between typical beliefs at the time the Fermi Paradox was formulated vs. typical beliefs now, I would say the experience of the shutting down of Apollo and overall reduction of human space exploration is probably the most relevant new observation we have made since then.

[1] In the sense of: You don't need nuclear armageddon to stop humans from spreading to other solar systems; the price tag of interstellar travel is sufficient.

Re: The Fermi Paradox

#30

Post by bdamm » Thu, Dec 25, 2014, 9:20 PM UTC

maaku wrote: post #10

The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…

This model assumes that interstellar travel is profitable. There is no evidence that this is the case, even if we had Star Trek technology.

If it isn't profitable, then it turns into a drain on the home planet. That isn't sustainable.