A Black Hole Is a Place, Not a Thing

Astrophysicist Janna Levin explains that a black hole's edge, the event horizon, is not an object but a boundary in spacetime itself, one-way and impossible to cross back over. In a few minutes she reframes what a black hole actually is, using language most explainers get wrong.

Why it's free: Free on NOVA PBS's own channel; GBH produces NOVA for PBS.