“The theory of quantum electrodynamics describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is — absurd.”Richard Feynman · QED: The Strange Theory of Light and Matter · 1985 · QED: The Strange Theory of Light and Matter, introducere
Picture a tiny clock hand spinning fast along every possible path light could take. Each path gets its own spinning arrow. Scientists add all those arrows together like tiny vectors. The length of the final arrow tells you how likely light is to arrive there. It sounds strange, but it works perfectly.
Why it matters This idea underlies lasers, the chips inside phones, and fiber-optic internet.