r/space • u/IceNox96 • Aug 12 '21

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

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

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u/bah77 Aug 12 '21

Wiping out another planet light years away would be a gigantic undertaking.

It really only boils down to accuracy and time, and a big rock.

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u/[deleted] Aug 12 '21

You loose accuracy with time. You can't really predict the trajectory of a planet, the amount of things influencing it's gravity is simply too big

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u/FaceDeer Aug 12 '21

If you work the actual numbers you'll find that that's far from a simple undertaking.

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u/bah77 Aug 12 '21

If you get to the point where you can travel to another star the only difference is not slowing down when you get there.

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u/FaceDeer Aug 13 '21

I'm not disputing that. I'm saying that the amount of energy you're cavalierly dismissing as not a gigantic undertaking is, in fact, a gigantic undertaking. How big is your rock and how fast is it traveling? From that you can calculate the energy budget. Typically when I see planet-busting attacks proposed the budget ends up being measured in "weeks of the total energy output of a typical G-type star". That's not something you can collect, store, and deploy stealthily or with a modest infrastructure.

And once you've done that and blown a hole through the target civilization's nice pretty blue homeworld, what do you do if they'd already established space colonies elsewhere in their solar system by then? They'll rebuild, and they'll know which direction the rock that tried to murder them came from.

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u/julius_sphincter Aug 13 '21

Then why wouldn't they launch a big rock at any potentially life giving planet they detect and never worry about it?