How the world’s longest running experiment breaks physics

Pitch Drop Experiment featuring long-time custodian John Mainstone in 2007

One drop falls every 10 years — questioning the very foundations of statistical physics. Is it solid or liquid? The answer it turns out, is not so simple and apart from being a fundamental unsolved problem in physics, cascades into our everyday lives.

In 1927, Professor Thomas Parnell started an experiment to demonstrate to students that some substances have both…