Book
Black Holes and Time Warps: Einstein's Outrageous Legacy
by Kip Thorne · 1994 · 1 reading card
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Black Holes and Time Warps: Einstein's Outrageous Legacy · 1994
Black holes are thermodynamic objects with entropy and temperature, linking gravity, thermodynamics, and quantum mechanics.
Thorne explains the revolutionary discovery that black holes have entropy proportional to the area of their horizon, not their volume. This means information about what fell into the hole is stored on its surface, like a hologram. Hawking showed that quantum effects near the horizon cause the hole to emit thermal radiation, losing mass and slowly evaporating. For example, a black hole with the Sun's mass would have a temperature billions of times lower than the cosmic background and would take 10^67 years to fully evaporate. This discovery created the information paradox: if the hole evaporates completely, does the information about what fell in disappear? The answer is still debated and directly links black hole entropy to the foundations of quantum mechanics and gravity.
“Bekenstein argued that a black hole must have an entropy proportional to the area of its event horizon, and Hawking showed that this entropy is real: black holes emit radiation and evaporate, confirming that they have a well-defined temperature and entropy.”