HalFinney comments on The Popularization Bias - Less Wrong

21 Post author: Wei_Dai 17 July 2009 03:43PM

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Comment author: HalFinney 19 July 2009 11:01:26PM 0 points [-]

Tilba, Wei's earlier post pointed to this article:

http://weidai.com/black-holes.txt

You might also need to know that computation can be done in principle almost without expending energy, and the colder you do the computation, the less energy is wasted. Hence being cold is a good thing, and black holes are very cold.

Comment author: Tiiba 20 July 2009 03:13:29AM 1 point [-]

I didn't get it right away, but now that I do, it's pretty ingenious. Let me see if I got it right. Build a big ball in space. If the ball was empty, starlight and cosmic background would heat it up, the inner surface would emit photons, and they would bounce around the shell - so you're back to square one. But the black hole at the center can absorb those photons without becoming hot. And the photons are unusable because they are ambient.

On the other hand, there is now a temperature difference between the inside and the outside. Can it be used to make usable energy?