Despite Werner Heisenberg's Nobel Prize for its formulation, Albert Einstein never accepted the so-called "uncertainty principle" (which stipulates that the more carefully one measures the position of a given particle, the less certain its momentum becomes) because it threatened to wreak havoc with the strict determinism in which he believed.

Indeed, the uncertainty principle was a subject about which Einstein and Niels Bohr argued many times over the years. On one memorable occasion (at the Solvay conference in Brusseis in 1930) Einstein unveiled the product of one of his famous "thought experiments": an imaginary device comprised of clocks and scales, which, he claimed, violated the principle.

Following a sleepless night, however, Bohr discovered that Einstein had made a critical error: he had neglected to take into account the fact that clocks run slower in a gravitational field... a consequence, rather ironically, of Einstein's own theory of relativity.