From: Reason (reason@exratio.com)
Date: Fri May 17 2002 - 05:30:27 MDT
--> Anders Sandberg
> On Fri, May 17, 2002 at 04:22:36PM +1000, Damien Broderick wrote:
> >
> > Is it terribly bad just to dump the degraded waste heat back on
> the central
> > star? It might burn faster, but that's all the more useful
> energy, no? and
> > you can always move, later on.
>
> The problem is that you would need to pay energy costs to heat up the
> star (moving heat from somewhere cold to somewhere hot), so it would be
> very inefficient. As the star heats up, it will tend to expand to remain
> in equilibrium. This will decrease the rate of fusion in the core, so
> its energy production will become less.
Eh, not necessarily. It all depends on where you're putting the energy into
the heating the star. If you put it into to outside of the star (e.g.
lasers), then nothing much will happen inside the star. The fuel-burning
core will keep doing what it's doing, and the outermost thin layer of the
non-burning shell will expand. In practice, your energy will remain in the
outer layers and you'll basically be evaporating your star rather messily.
Not sure how messily.
If you put it into the core (e.g magic physics, can't think of a way to do
this offhand), you may be ok. Not sure. Open question as to whether you'd
cause the star to expand or increase its own rate of energy production (or
both).
> > And is it in fact feasible to turn all your heat noise into,
> say, IR laser
> > light and beam it that accurately at black holes?
>
> Entropy is nasty; lasers can't transmit much entropy (and producing them
> causes plenty of entropy). I think a better idea would be to have a
> spherical cavity surrounding the hole, perhaps connected to it by some
> electromagnetic fields.
Now what would be useful is a hole in the center of your star, surrounded by
some vacuum (if you do the math, you find that it's pretty hard to tell the
difference between a normal star and a normal star with a black hole in the
middle without performing neutrino measurements or waiting around for a long
time)...that way you might be able to engineer things to eat excess energy
for a while.
Reason
http://www.exratio.com/
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