Physics Laws & Theorems
Advanced

Second Law of Thermodynamics

The entropy of an isolated system never decreases.

Formula

ΔSuniverse≥0\Delta S_{universe} \ge 0

Variables

SEntropy

Example

Heat flows from hot to cold on its own, never the reverse — entropy always increases.

Did You Know?

The second law gives time its arrow: entropy always increases, which is why you can't unscramble an egg.

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