Negative heat capacity occurs when adding energy to a system results in a decrease in temperature, which seems counterintuitive and challenges traditional thermodynamic principles. Black holes are a primary example, as they exhibit this phenomenon due to their unique gravitational properties. Additionally, certain paramagnetic systems at low temperatures can also display negative heat capacity under constant pressure. Gravitationally bound systems, not limited to black holes, generally demonstrate this behavior as well. Understanding these concepts requires a deeper exploration of thermodynamics and gravitational physics.
