That's like saying making a star go supernova is a great way to generate energy for an advanced civilization — there are some huge leaps in logic in making sweeping assumptions of that scale. It would be like someone in the Victorian era predicting that we'll farm whales for their oil...
There's a problem with this approach: black holes evaporate, which would yield a useful-life ceiling of 10^100 years. I know I'd like my machines to work longer than that.
You're going to have some major practical trade-offs with this choice of cooling system. For one thing, any data you get out of this computer when you're positioned further away from the event horizon is going to be red-shifted down to a lower data rate.<p>For another thing, the electrical and magnetic fields generated by your computing and data transmitting hardware are going to induce a Lorentz force on the event horizon and torque it into rotation, which in turn produces both gravitational frame dragging and dissipation. Now it's a lot hotter than if it were just a Schwarzchild black hole emitting only Hawking radiation.
I think science fiction writer Arthur C. Clarke said it best "Any sufficiently advanced technology will indistinguishable from magic." I paraphrased so don't hurt me if I didn't get it word for word. I have to agree with him that any civilization that was advanced as the essay speculates, would seem like real magic to our relatively young civilization.
When you cool something down to near absolute zero it can turn into a Bose–Einstein condensate (BEC). <a href="http://en.wikipedia.org/wiki/Bose-Einstein_condensate" rel="nofollow">http://en.wikipedia.org/wiki/Bose-Einstein_condensate</a> For example at 1.7×10^-7K rbidium turns into a BEC. At 10^-8K perhaps that would turn normal matter into a BEC. Then you would have to be able to get useful information out of a state of matter where every possible value exists at once, and the tool your using to read values warms the condensate past the point of being one. Hey - I think you just invented a quantum computer. Congrats.<p>On a site note I think lasers are the advanced cooling system of the future!
That's a really good idea.<p>Come to think of it, could black holes actually be used as an energy source? A setup like the one he describes would create a temperature gradient, and it's easy to extract power from that.<p>That would only make sense if this process somehow "depleted" the black hole; otherwise one could reverse entropy. IANA theoretical physicist so I don't know which mechanisms would be at work here.
Theres a more thorough exploration of using a black holes in a reversible Carnot Cycle here: <a href="http://dx.doi.org/10.1088/1674-1056/18/3/015" rel="nofollow">http://dx.doi.org/10.1088/1674-1056/18/3/015</a> unfortunately behind a paywall.