[ExI] The Fermi Paradox

Ben Zaiboc ben at zaiboc.net
Sat Mar 7 16:27:10 UTC 2020

On 07/03/2020 06:23, Adrian Tymes wrote:
> I am reminded of stories where the last humans in a solar system took 
> their city mobile, sticking to the slim (and moving) spot on the 
> planet that was sufficiently shielded and life-compatible, with crews 
> working the terrain ahead so the city could stay on the march.

OK, so that's one possible defence. Pick a massive body that's certain 
to withstand the onslaught and provide enough shielding, and stay behind 
it. For as long as it takes. You'd have to be completely self-sufficient 
(which pretty much rules out any biological existence, I would think), 
and able to maneouvre to stay in the shielded spot.

I imagine gas giants would get shredded by this kind of event, and stars 
are probably not dense enough to provide the shielding needed, so that 
leaves large rocky planets like the earth. I can't see crawling around 
on the surface like in those stories being viable (storms, vulcanism) 
and of course an orbit would be useless, so what does that leave? Going 
deep underground (as in, in the mantle)?

If a shell of dense rock was constructed, and a civilisation located at 
the centre (uploads in some nano-structured substrate, say), how thick 
would the rock need to be? Can anyone do the maths on this? One 
supernova per month, indefinitely, from say our galactic centre?

Altenatively, how big would your computational parts (logic gates, or 
their equivalent) need to be, to be indifferent to a barrage of intense 
radiation like that? Would a civilisation made of beer cans and string 

Is there something that could even use the radiation to its advantage, 
and thrive in an evironment like this?

Ben Zaiboc

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