Mathematics I / Thermodynamics and Statistical Ideas
Practice question · Multiple choice

The second law says entropy tends to increase, yet nothing in Newton's laws forbids a broken cup reassembling. How can a statistical tendency be as reliable as a law?

Hints
  1. Count the arrangements: how many ways are there to be shattered versus intact?
  2. Ask whether the reassembly is impossible or merely overwhelmingly improbable.
Show the answer

D. Because disordered arrangements overwhelm ordered ones utterly.

Why

The microscopic laws really are reversible and a reassembling cup violates none of them; what rules it out is counting, and at 10²³ particles the ratio is smaller than anything observable in the age of the universe. The statistical reading is testable: in systems of a few particles entropy decreases are routinely measured, and the fluctuation theorems say how often.

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