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417 points fuidani | 2 comments | | HN request time: 0s | source
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seanhunter ◴[] No.43714467[source]
Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me.

Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life developed here I always felt it overwhelmingly likely that it developed elsewhere too given how incredibly unfathomably vast the universe is.

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ta8645 ◴[] No.43714565[source]
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise too, will come before too long.

If, on the other hand, life is relatively rare, or we're the sole example, our future can't be statistically estimated that way.

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ivan_gammel ◴[] No.43714706[source]
> And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

If dark forest theory is right, alien civilizations may stay undetectable by hiding biological signatures of their worlds.

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cedilla ◴[] No.43714793[source]
The dark forest theory makes for a great book premise, but it probably doesn't apply in real life simply because the distances are so far.

The universe is not a forest. It's a gigantic, empty ocean. The next, dangerous tribe is not lurking behind a bush 2 meters away, but is sitting on an island that's so far away it will take centuries to go there, if it is possible at all

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autonomousErwin ◴[] No.43715012[source]
Isn't that the point of the dark forest theory? It's not the fact that there is a dangerous tribe behind a bush it's more that you don't know if they're dangerous or not so you have to err on the side of caution - because you don't know if they're doing the same.

It's the whole chain of suspicion theory that it's safer to shoot first and then ask questions later because the speed you can communicate is the same speed you can mount an attack.

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cedilla ◴[] No.43715064[source]
Yes, but the next bush is dozens of light years away. The analogy breaks down because the distances are different in quality.

The only reason why this becomes such a problem in the Three-Body-Problem is the existence of magic in that universe. Thinking protons, instant communication, folded dimensions, easy interstellar travel, it's all interesting speculation inspired by physics, but incompatible with our actual universe.

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1. zaphirplane ◴[] No.43715254{6}[source]
Why does the distance change the dynamic? So what if the species trying to exterminate you are 500 light years away, you think they should ignore it ? Maximum travel speed of an extermination weapon in 100,000 years of of science may very much be impressive or even magical by today’s standards
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2. cedilla ◴[] No.43718873[source]
The distance completely changes the dynamic. If I tell you there's a crazy axe murderer in your house, you should be afraid. If I tell you there's a crazy axe murderer on Venus, how afraid are you?

And unless we are completely wrong about physics, the maximum speed of a weapon will be the same as it today - very close to 1c.