Day 273/365 of sharing my teaching practices : collision of two light beams - principle of superposition .When two lasers cross each other… do they collide? No! Unlike cars at an intersection, light waves follow the Principle of Superposition. At the crossing point the electric field of each beam is superpositioned. For an instant, they add together by vector addition . Each beam continues on its own path completely undisturbed. There is no interaction. In simple words — light doesn’t interact w