Re: starship-design: Re: Aliens

[kyle <stk@sunherald.infi.net>]

Steve VanDevender wrote:
> 
> Yes, but it argues against you, not for you.
> 
> The problem for your argument is that the water cycle depends on an
> external energy source, the Sun, to work.  When a hydroelectric
> generator extracts energy from a river, it's extracting energy that was
> put there by the Sun evaporating water, which dispersed into the
> atmosphere, precipitated on land, and settled back toward the ocean.
> The hydroelectric generator just slows down the settling slightly and
> gets a fraction of the energy put in by the Sun as a result.
> 
> Conservation of energy implies that if energy is removed from the
> vacuum, it is _removed_.  If you put it all back then there's nothing
> left over for you to work with.  If you extract energy and turn it into
> motion or photons or mass, then you can't have put it all back.  ZPE, in
> a very real sense, gets something from nothing.  Matter and energy don't
> react to produce vacuum -- the reactions always produce photons or
> particles -- so the energy extracted, if it is in any useful form, can
> never be put back.

Why doesn't ZPE deplete? Your guess is as good as mine.

Kyle Mcallister