CLERK MAXWELL'S original suggestion, revived in NATURE for April 12, p. 566, was in danger of being lost sight of, although it has been renewed independently from time to time; see, for example, Phil.

THE following is a preliminary report of an investigation performed to test directly, in a terrestrial experiment, the second postulate of special relativity, which states that the velocity of light ...

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 ...

For over 100 years, two theories have shaped our understanding of the universe: quantum mechanics and Einstein’s general relativity. One explains the tiny world of particles; the other describes ...