Black Hole Firewalls Could Be Too Tepid to Burn - Facts So Romantic

Reprinted with permission from Quanta Magazine's Abstractions blog. Despite its ability to bend both minds and space, an Einsteinian black hole looks so simple a child could draw it. The point is the singularity, an infinitely dense, unimaginably small dot contorting space so radically that anything nearby falls straight in, leaving behind a vacuum. The spherical boundary marks the event horizon, the point of no return between the vacuum and the rest of the universe. But according to Einstein's theory of gravity, the event horizon isn't anything that an unlucky astronaut would immediately notice if she were to cross it.