4 ms·
The event horizon isn't the surface of the black hole. As classically defined, the event horizon is the point at which the black hole's gravity becomes inescapa
by rosser 13y ago
The event horizon isn't the surface of the black hole. As classically defined, the event horizon is the point at which the black hole's gravity becomes inescapable. That's not at its surface.
- panzi 13y agoExactly.
- pdonis 13y agoThe event horizon isn't the surface of the black hole. As classically defined, the event horizon is the point at which the black hole's gravity becomes inescapable. But the horizon isn't a point; it is in fact a surface (a 3-surface in 4-dimensional spacetime). Whether you want to call that the "surface" of the black hole is a matter of terminology; the hole is not a solid object--it's not really an "object" at all in the ordinary sense of the term, so it doesn't have a "surface" in the ordinary sense of the term.