Photons are the fundamental particles of light, and unlike everyday objects, they cannot simply be cut into smaller pieces. A new theoretical study explores what would happen if scientists attempted the impossible: slicing a single photon in half. Rather than producing two smaller photons, the calculations predict that the process would generate multiple entirely new photons, revealing another counterintuitive feature of quantum physics, tells Science News.
The research considers a photon traveling through an optical shutter, essentially an ultrafast mirror that can switch on or off quickly enough to block part of the photon’s wave. Although a photon behaves as an indivisible quantum particle, it also exists as a wave spread across space. Intercepting only part of that wave raises an intriguing question: What becomes of the remaining light?
Using a mathematical model, researchers found that cutting off part of a photon does not leave behind a smaller particle. Instead, the act of interrupting the wave creates a quantum superposition containing different possible numbers of photons. In theory, removing the mirror instantaneously would produce an infinite number of photons, though such a process is physically impossible. At realistic speeds, the outcome is far less dramatic but still remarkable, with the highest probability favoring the creation of only a few additional photons rather than vast swarms.
The findings reinforce the unusual nature of quantum mechanics, where particles cannot always be understood using classical intuition. A photon is not a tiny object that can be divided like a grain of sand. Its particle and wave characteristics are inseparable, and attempts to manipulate one aspect can fundamentally alter the quantum state itself.
Although the work remains theoretical, it provides new insight into the behavior of light at the quantum level. The results could deepen physicists’ understanding of quantum field theory and inspire future experiments that probe the limits of light manipulation, helping refine technologies for quantum communication, photonics, and precision optical systems.
