Astronomy Fundamentals

Time, Waves, and Particles

What is the twin paradox?

If objects traveling at different speeds through space experience the passage of time differently, then it is possible to imagine a situation in which a pair of identical twins could wind up as two people of different ages. If one of the twins were placed on a fast-moving vehicle at birth, and the other twin were to stand relatively still, then they would age at different rates. This is called the “twin paradox.”


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