A photon emitted from a star a billion light-years away arrives at a telescope having experienced no time whatsoever. Not ...

A spacecraft traveling at 99 percent the speed of light toward Alpha Centauri would cross 4.3 light-years in what feels like months to its crew, while decades tick by on Earth. That asymmetry is not ...

Tracking time is one of those things that seems easy, until you really start to get into the details of what time actually is. We define a second as 9,192,631,770 oscillations of a cesium atom.

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

I am so intimidated right now...I think I understand less about relativity now than before I asked the question. I think - if I understand things as written - that time can be observed to slow for an ...