Researchers have bent one of the most basic rules of quantum mechanics, a counterintuitive branch of physics that deals with atomic-scale interactions. Its “complementarity” rule asserts that it is impossible to observe light behaving as both a wave and a particle, though it is strictly both. In an experiment reported in Science, researchers have now done exactly that.
See also Physics World:
An international team of researchers has, for the first time, mapped complete trajectories of single photons in Young’s famous double slit experiment. The finding takes an important first step towards measuring complimentary variables of a quantum system – which until now has been considered impossible as a consequence of the Heisenberg uncertainty principle.
Picture above (from Physics World):
This 3D plot shows where a quantum particle is most likely to be found as it passes through double-slit apparatus and exhibits wave-like behaviour. The lines overlaid on top of the 3D surface are the experimentally reconstructed average paths that the particles take through the experiment. (Courtesy: Krister Shalm and Boris Braverman).