Maxwell's equations
Electricity, magnetism and light turn out to be the same thing.
- When
- Known to
- ± 1 year
- Era
- Industrial, Holocene
Maxwell's 1865 formulation unifies electric and magnetic phenomena into four equations, and shows that the waves they predict travel at the measured speed of light — so light is an electromagnetic wave. It is the second great unification in physics after Newton, it predicts radio waves before anyone has produced one, and its inconsistency with Newtonian relative motion is precisely the problem Einstein resolves forty years later.