Electromagnetic Radiation: Feynman's Physics Explained
An accelerating electric charge disturbs the electric and magnetic fields around it, and Maxwell's equations say that disturbance spreads outward as a wave traveling at the speed of light. That wave is light. Crucially, the strength of this radiation field falls off only as 1/r, not 1/r^2, so its energy can cross the entire universe without dying away — which is why we can see the stars.
The big idea
Light is a wave made by jiggling electric charges.
Think about it
Starlight has traveled for thousands of years to reach you. What about radiation lets it survive such an immense journey?
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