Scientists studying radiation from a distant gamma-ray burst have found that the speed of light does not vary with wavelength down to distance scales below that of the Planck length. They say that ...

Tachyons are hypothetical particles that travel at speeds greater than the speed of light. These superluminal particles, are the "enfant terrible" of modern physics. Until recently, they were ...

Gravitational physics has become a truly experimental science as tests of the special and general theories of relativity reach new levels of precision Right on time When I was a first-term graduate ...