The phenomenon of light slowing down as it passes through ... All material is constantly in motion, and that motion affects how that material interacts with everything else. To help physicists ...

Faint light from the oldest galaxies is still traveling ... as another type of cosmic clock that allowed them to track the slow-motion movement of the universe to about half of its current age.

About 2,600 light-years away, a dead star is sending signals from beyond the grave. Astronomers recently found the strange beacon, which appears to be a pulsar blinking in slow motion - something ...