Seeing a cat with photons that aren’t there
Quantum mechanics allows some mind-bending effects. A recent paper shows us how to make an image of the silhouette of a cat using a set of photons that had never interacted with the cat object. The photons that had actually interacted with the cutout, and carried information about it, had even been discarded. The explanation depends on the ideas of quantum superposition and interference; the trick is in transferring quantum information from one set of photons to another.