Interesting. That's 10^14 kg, which, according to the above, would be between 10^24 and 10^27 seconds to evaporate, which is at least in the quadrillions of ye

Interesting. That's 10^14 kg, which, according to the above, would be between 10^24 and 10^27 seconds to evaporate, which is at least in the quadrillions of years. As for the radius... Looks like the Schwarzchild radius is proportional to the mass, and for the moon (7x10^22 kg) it's 0.11x10^-3 meters, so this 10^14 kg mass should be maybe 1.5x10^-13 meters, which is 1.5 x 10^-11 cm. Nice. It looks like Niven did his homework. Incidentally, Wiki says that Hawking argued for black hole evaporation in 1974, and Niven's story won an award in 1975, which I assume might indicate it was published around then. Seems it'd be a close call whether Niven heard about it before publishing his story.