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 ...

What does it mean to be to space-time? The seemingly simple question gets to the essence of twentieth-century physics and has driven a hundred-year debate between philosophy and science. In Einstein’s ...

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.

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.