Physicists Split a Photon and Discover an Infinite Cascade of New Ones

Physicists at the University of Oslo have discovered that truncating a single photon with an optical shutter does not split it, but instead generates a complex state containing an infinite number of new photons, according to new research published in Physical Review Letters. The team modeled a single photon passing through a mirror-like shutter in a simplified one-dimensional scenario. They found the process yields one pure vacuum and one complete photon, with neither fragment showing evidence of being part of a larger whole, defying common-sense expectations. Photons possess an "infinite tail" that trails in only one direction, making them inherently asymmetrical and meaning the cut's location matters significantly. The researchers suggest their formulation could aid scientists studying perturbed states and causality in future optical experiments.