Re: Brown dwarves, deep future

Tim Little wrote:
> Stars (even cool M dwarves) probably put out vastly more power than
> the civilization needs to survive.  Just putting very rough numbers to
> it: suppose they need 10^16 W.  From the brown dwarf stars, they've
> probably got reserves of something like 10^39 kg of hydrogen, with a
> fusion energy density of rather more than 10^14 J/kg.  In theory
> that's enough for 10^30 years - on the order of a billion times that
> of the M star method.

I think this depends a lot on what population you intend to support.
If the population is 1, you need very little energy. If you think
a thriving civilization really needs a population of at least
10^12, then you need more.