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 ...

In the realm of physics, the speed of light is considered one of the most fundamental constants in the universe, dictating ...

Discover how Einstein’s theory of special relativity reshaped physics by linking space, time, mass, and energy in a universe governed by the speed of light.

The speed of gravity not only equals the speed of light to an incredibly precise degree observationally, but these two constants must be exactly equal theoretically, or General Relativity would ...

A snapshot of relativistic motion: visualizing the Terrell-Penrose effect. Communications Physics , 2025; 8 (1) DOI: 10.1038/s42005-025-02003-6 Cite This Page : ...

Special relativity also affects many other things physicists measure—for example, the frequency and intensity of light and also the size of an object’s appearance.

Special relativity is also based on a second assumption that gives the speed of light — 186,000 miles per second (300 million meters per second) — in a vacuum a special status.

Consider two clocks, one located at the North or South Pole, and the other at the equator. The clock at the equator would tick slower because of its relative speed due to Earth’s spin, but faster ...

NASA's IXPE satellite has identified a supermassive black hole blasting its energetic jets toward Earth. Don't worry, though, the powerful blazar far away in space.