Special relativity

In 1905 Albert Einstein built his special theory of relativity on two postulates. First, the laws of physics are the same for all observers moving at a constant velocity relative to each other. Second, the speed of light in a vacuum, about 300,000 km/s, is the same for all such observers, no matter how fast the light's source or the observer is moving. These simple ideas lead to surprising results that become large only near the speed of light. Time dilation: a clock moving relative to you runs slow as you measure it, which is why muons created high in the atmosphere survive long enough to reach the ground. Length contraction: a moving object is measured to be shorter along its direction of motion. Relativity of simultaneity: two events that happen at the same time for one observer may not for another. No object with mass can be accelerated to the speed of light. Relativity also shows that mass and energy are equivalent, through E = mc^2. At everyday speeds these effects are tiny, but GPS satellites must correct for relativity, both special and general, to give accurate positions.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report