Philosophical-sounding edge cases help scientists refine their models and explore how and where their theories may fail.

What's more, when you're traveling at or close to the speed of light, the distance between where you are and where you're going gets shorter. That is, space itself becomes more compact in the ...

For the first time, physicists have simulated what objects moving near the speed of light would look like — an optical illusion called the Terrell-Penrose effect.

Cosmic speed limits can be a major inconvenience but they've rarely stopped science fiction in its tracks. When it comes to space travel, Albert Einstein's theory of relativity is a major ...