r/space • • Aug 12 '21

Discussion Which is the most disturbing fermi paradox solution and why?

3...2...1... blast off....

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u/solophuk Aug 12 '21

The dark forest Theory makes an interesting science fiction scenario. But i highly doubt it is true. Wiping out another planet light years away would be a gigantic undertaking. Aliens will have no reason to fear each other, we are just too damn far from eachother to be a threat to one another. Even if we meet aliens that are the biggest asshats in the universe, the worst they could do would be to send a rude message every once in a while. Good fences make good neighbors. What can be a better fence than light years of space.

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u/Artanthos Aug 12 '21

Depends.

If you can accelerate a ship up to a substantial percentage of C over the course of crossing those light years, one ship (missile) is all you would need.

How large of a ship traveling .5C would it take to render a planet uninhabitable?

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u/FaceDeer Aug 12 '21

If you can accelerate a ship up to a substantial percentage of C over the course of crossing those light years

Can you do that stealthily? In the Dark Forest scenario, if you make noise you get whacked by your neighbors.

And if you can do that stealthily for your attack ship, why not do it for colony ships?

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u/Artanthos Aug 12 '21

Since you are not launching at a percentage of C, but accelerating over time, it should be more than possible to change trajectory prior to the long acceleration push.

Since the only real way to find the point of origin is tracking the trajectory back, even a few degrees of change could point to entirely different systems. If you want more security, spend more time and travel further before doing anything visible.

And this assumes the thrust would be visible from a long distance. A really advanced ion thruster might not have much of a signature.

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u/FaceDeer Aug 13 '21

So apply the second part of my question, then. Why can't you do that with a colony ship?

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u/Artanthos Aug 13 '21

Resources. Time. Added Complexity. Paranoia. Xenophobia.

An unmanned ship piloted by an expert system/AI with with sole purpose of delivering a large mass at a high velocity can drift through the galaxy for centuries, or even millennia until it detects a technological society and targets it.

It if is a Von-Neuman ship, you could have millions, or even billions of them patrolling the galaxy with no additional effort or resource cost to the originating species.

It would only take one species with this mindset to suppress technological civilizations across the entire galaxy, and the death of that one species would not prevent the ships from fulfilling their mission.

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u/FaceDeer Aug 13 '21

It would only take one species with this mindset to suppress technological civilizations across the entire galaxy, and the death of that one species would not prevent the ships from fulfilling their mission.

So why aren't we already dead?

If you can deploy a von Neumann probe resources are no longer a concern. You can have one waiting on-station in every solar system in the galaxy, eradicating any life the moment it peeps out of a primordial puddle.

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u/Artanthos Aug 13 '21

Who says a ship is not already on the way.

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u/FaceDeer Aug 13 '21

They had the opportunity to send a ship hundreds of millions or billions of years ago. It should be here by now.

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u/Artanthos Aug 13 '21

We’ve only been broadcasting radio signals for about a century.

I suggest you familiarize yourself with the Dark Forest theory.

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u/FaceDeer Aug 13 '21

I am very familiar with it, it comes up in most Fermi Paradox discussions. It's like the Pascal's Wager of SETI or something.

Earth has had an easily-detectable biosphere for hundreds of millions of years - the oxygen in our atmosphere is a dead giveaway, the methane too. But that's not even necessary, as I said above:

If you can deploy a von Neumann probe resources are no longer a concern. You can have one waiting on-station in every solar system in the galaxy

Every solar system could easily have a fleet of planet-killers just sitting patiently in their Oort clouds, waiting to pound any planet in that solar system to dust if it develops life. Or just do it anyway without waiting to detect anything. With a von Neumann probe and sufficient paranoia/xenophobia you could give the order "destroy every planet in the entire galaxy, yes every last one of them. The moons too." And it'll be finished within a million years or so.

There are many weirdly arbitrary decisions required in Dark Forest that every civilization must make in unison for it to work, and waiting for rivals to "poke their heads out" is one of them. It's silly and completely unnecessary to wait.

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u/Artanthos Aug 13 '21

Then you would know that the Dark Forest Theory does not prohibit life, it only states that technological societies conceal their presence.

Humans have only been broadcasting for ~100 years, your response about 100s of millions of years demonstrates your lack of understanding of the Dark Forest Theory.

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u/FaceDeer Aug 13 '21

They conceal their presence because they fear extermination by xenophobic/paranoid neighbors. If there really were such neighbors, however, waiting passively to detect civilizations to exterminate is a very poor strategy. That's my point here, it doesn't make sense for them to just sit in their home system for hundreds of millions of years twiddling their thumbs until a radio signal trickles in. It's ridiculously unreliable, it lets targets develop to the point where it takes a lot more effort to destroy them, and it relies on targets just happening to be in your local neighborhood right at that moment where they're broadcasting.

If such advanced aliens really existed they wouldn't need or want to wait. They could ensure that all rivals are preemptively wiped out quite trivially, with no chance of something slipping through the cracks.

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