Why do black holes form?

Answer: Massive stars collapse

Planets compress together — Wrong. Planets don't have enough mass. Black holes form when massive stars (>20 solar masses) collapse under gravity after supernova.

Space tears from rotation — Wrong. Space doesn't tear. Black holes form from gravitational collapse of massive stars—density becomes so high nothing escapes, not even light.

Massive stars collapse ✓ — Correct! When massive stars (>20 solar masses) exhaust fuel, fusion stops. Gravity collapses the core. If massive enough, no force can stop collapse—it becomes black hole. Escape velocity exceeds light speed—even light can't escape! Event horizon marks point of no return. Schwarzschild radius depends on mass. Stellar-mass black holes form this way. Supermassive black holes (galactic centers) formed differently—still debated!