How long would the Earth last if the sun became a black hole?

[DavidSh]

In a thread pulled back from the brink of extinction:

I mean, we must be increasingly on the alert to prevent them taking over other mine shafts space, in order to breed more prodigiously than we do. Thus, knocking us out of these superior numbers when we emerge! Mr. President, we must not allow a mine-shaft gap!

Quite fitting, ain't it?

I was just watching Dr Strangelove a few weeks ago. There is a sub-genre of fiction about societies set underground to avoid the effects of nuclear war.

Some of our deeper mines, that now require active cooling, might end up with habitable temperatures. I don't know whether we would have the time to construct new underground habitations before the surface becomes deadly. Ocean tides would be much harder to use when the top few hundred meters of the seas have frozen solid.