QED: The Strange Theory of Light and Matter

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   Light behaves not like a smooth wave but like tiny particles called photons, and the chance a photon lands somewhere comes from adding up little spinning arrows.

   QED: The Strange Theory of Light and Matter · 1985

   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.

   “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.”

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