Relativistic Effects in Radiation: Feynman's Physics Explained

Feynman Vol I8-9

When a source of radiation moves near the speed of light, spectacular things happen. The radiation gets beamed into a narrow forward cone and its frequency shifts through the Doppler effect. An electron whirling in a synchrotron, for instance, emits sharp, intense pulses we see as synchrotron light. These effects follow directly from combining Maxwell's equations with special relativity.

The big idea

Near light-speed, radiation beams forward and shifts color.

Think about it

A siren's pitch drops as the ambulance passes. How is the Doppler effect for light similar?

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