Hawking's Area Theorem

Hawking's Area Theorem states that the total surface area of a black hole’s event horizon—its boundary beyond which nothing can escape—never decreases over time, assuming classical physics applies and no new matter or energy falls into it. In simple terms, as black holes merge or absorb matter, their horizons can grow larger, but they never get smaller. This is similar to how entropy (disorder) in thermodynamics never decreases, highlighting a fundamental physical law that black holes can't spontaneously shrink, emphasizing the irreversibility of certain processes in the universe.