Einstein’s twin paradox is a thought experiment in the theory of special relativity in which there are a pair of twins.
- One takes a space voyage at close to the speed of light
- The Other remains at home on Earth
When the travelling twin returns home, they find that the twin who remained on Earth has aged more. This result appears puzzling because each twin sees the other twin as having had travelled near the speed of light.
To find out more about the twin paradox and how it is resolved take a look the Explaining Science Video below
Introduction to Einstein’s Theory of Special Relativity.
For a general introduction to Einstein’s theory of special relativity then there is the video below
Explaining Science 