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Re: starship-design: Re: Aliens
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