The theory of special relativity is rife with counterintuitive and surprising effects, the most famous of which are length contraction and time dilation. If an object travels at a relative speed, ...

When an object moves extremely fast—close to the speed of light—certain basic assumptions that we take for granted no longer apply. This is the central consequence of Albert Einstein's special theory ...

A spacecraft traveling at 99 percent the speed of light toward Alpha Centauri would cross 4.3 light-years in what feels like months to its crew, while decades tick by on Earth. That asymmetry is not ...

Sciencephile the AI explains Einstein's 1905 special relativity and why events that seem simultaneous to one observer can ...

This article predates the current owners of Science Blog. It has not been reviewed under the current editorial process and is kept as part of the archive. Einstein’s special relativity is sometimes ...

Why do moving rulers shrink (length contraction) and moving clocks run slow (time dilation) such that everyone measures the same speed of light c, regardless of their relative motions? Einstein ...

The contraction of a measured length of an object or a distance in a frame of reference moving at nearly the speed of light, predicted by the theory of special relativity.