I learned in October 2022’s Breakthrough that the spikes of stars in high-power photos are called diffraction spikes. Why do they appear as two crosses at 45 degrees to each other? The diffraction ...

Imperial physicists have recreated the famous double-slit experiment, which showed light behaving as particles and a wave, in time rather than space. The experiment relies on materials that can change ...

A closed door feels absolute. Light stays in one room, darkness settles in the next, and the boundary seems obvious enough to stop thinking about. Yet the same wall that blocks the glow from your ...