## TL;DR

A black hole is a region of spacetime where gravity is so strong that nothing — not even light — can escape. Formed when massive stars collapse. Event horizon: point of no return. Hawking radiation (1974): black holes slowly evaporate via quantum effects. First image captured by Event Horizon Telescope (2019, M87 galaxy).

## Core Explanation

Schwarzschild radius: 2GM/c² — defines event horizon. Spaghettification: extreme tidal forces stretch objects near black hole. Information paradox: does information disappear in black hole? (Hawking vs. Susskind, settled: information preserved on event horizon). Supermassive black holes: center of most galaxies (Sagittarius A* in Milky Way, 4 million solar masses). Gravitational waves from black hole mergers (LIGO, 2015).

## Further Reading

- [A Brief History of Time (Stephen Hawking)](https://www.penguinrandomhouse.com/books/26703/a-brief-history-of-time-by-stephen-hawking/)