In wave physics, few phenomena are as visually poetic and intellectually profound as interference—the process by which light waves interact to either amplify or diminish one another. At its heart, light is a wave—an oscillation of electric and magnetic fields moving through space. When two or more light waves cross paths, they do not simply pass through each other unaffected, as particles might. Instead, they superimpose, combining their oscillations in a process governed by the principle of sup