Add Yahoo as a preferred source to see more of our stories on Google. GPS satellites must account for and correct for time dilation For centuries, humans have thought of time as a linear concept - but ...

Oftentimes, we think of space as an endless, mostly empty vacuum, a silent backdrop where planets, stars, and galaxies play out their dance. We also think of time as something separate, a steady ...

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.

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. "That's the Pinwheel galaxy," I said. The name is derived from its shape – albeit this pinwheel contains about a trillion stars.

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 ...