Via New Scientist:
‘A black hole sun could be friendlier than you might expect. Planets orbiting a black hole – as they do in the film Interstellar – could sustain life, thanks to a bizarre reversal of the thermodynamics experienced by our sun and Earth.
According to the second law of thermodynamics, life requires a temperature difference to provide a source of useable energy. Life on Earth exploits the difference between the sun and the cold vacuum of space, but what if you flip the temperatures around, with a cold sun and a hot sky?’