From: Doug Jones (random@qnet.com)
Date: Mon Aug 23 1999 - 00:08:13 MDT
Eugene Leitl wrote:
>
> Speculations of manufacturing miniature black holes by focusing the
> output of e.g. Dyson sphere lasers on a small region of space have
> been discussed here before.
>
> Iirc Sol is losing about 2 MT/s mass (though probably mostly to
> protons which go out as solar wind).
Not protons, photons- 1 AU is 150E6 km = 1.5E11 m, sunlight is 1350 W/m2 at
earth, so total power out = 4piR^2(1350) = 3.8E26 W. E=MC^2, so
P = MdotC^2 and Mdot = P/C^2 = 4.2E9 kg/s = 4.2 MT/s
Four million tonnes of energy per second is one hell of a lot of power.
Current total human power usage is around 10 terawatts, give or take an
order of magnitude... or about 0.01 g/s.
Total insolation on Earth is about 1.7E17 W, or about 1.9 kg/s.
Four million tonnes of energy per second is one HELL of a lot of power.
With a really *big* chirped diffraction grating (tens of lightseconds on a
side) you could create attosecond pulses with megatonne mass. Colliding
these pulses[*] should create tidy little black holes. It may require
hundreds or thousands of seconds of the sun's output to make black holes
that have evaporative lifetimes of at least a few years, so that they can
be trapped and used. The energy in the beams must all reach the target
volume in less time than it takes for a photon to traverse the "width" of
the hole. Yoctosecond timing?
About the best use of black holes is the fact that they don't conserve
baryon number, so you can turn any old mass (even iron) into energy. The
very high temperature of a black hole would allow very high carnot
efficiency.
-- Doug Jones, Freelance Rocket Plumber [*] to avoid the circular firing squad's dilemma, more than two beams are needed so that missed pulses don't fry the opposite launch optics. Four beams originating at the corners of a tetrahedron should work... but more would produce a smoother implosion. Asymmetries in the implosion will cause the resultant hole the shoot off in the opposite direction. Thus two beams meeting at right angles could create a hole shooting off at .7 c
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