Pioneering experiments have cast doubt on a founding idea of the branch of physics called quantum mechanics.
The Heisenberg uncertainty principle is in part an embodiment of the idea that in the quantum world, the mere act of observing an event changes it.
But the idea had never been put to the test, and a team writing in Physical Review Letters says “weak measurements” prove the rule was never quite right.
That could play havoc with “uncrackable codes” of quantum cryptography.
Quantum mechanics has since its very inception raised a great many philosophical and metaphysical debates about the nature of nature itself.