Nothing Outruns Light

In 1905, Einstein started with one radical assumption: the speed of light in a vacuum is 299,792,458 m/s for every observer, regardless of how fast they're moving. Whether you're standing still or racing at half light speed, you'll measure the same value.

If light speed is constant for everyone, then something else must give. Einstein showed that time itself bends to accommodate this rule. Two people moving at different speeds experience time at different rates. Moving clocks genuinely tick slower.