A new thought experiment makes it clearer than ever that photons aren’t simply particles or waves.
Quantum physics tells us that a photon isn’t strictly a particle or strictly a wave. And yet most of us will revert back—whenever we can—to familiar concepts of billiard balls or vibrating strings when picturing photons in our heads. A new thought experiment, proposed in Physical Review Letters, hopes to break us of these old habits. The authors imagine a type of quantum switch that controls whether a simple optical measurement tests for particlelike or wavelike behavior in a single photon. This slight reworking of a famous experiment demonstrates with logical precision the futility of trying to label the photon as a particle or a wave.
To read more, click here.