Q&A: Black Holes

Q:
What is the life cycle of a black hole? Do they implode? Explode? What happens to them at the end of the "Big Bang"?

A:
As long as it has material to "feed" on, a black hole will continue to grow. The process of accreting material releases enormous amounts of energy, which can blow away some of the surrounding matter, so a black hole may in this sense regulate its own growth. As for the ultimate fate of black holes, some scientists have speculated that in the far distant future after all the stars have burned out, elementary particles have decayed into neutrinos and gamma rays, black holes will eventually evaporate by the Hawking process. The time for this process is huge, being about a 100 trillion octillion yotta-years, or 1 followed by 65 zeroes, for a 10 solar mass black hole, and a quintillion times longer than that for a 10 million solar mass black hole! (1 yotta-year = a trillion trillion years).