For centuries, humans have thought of time as a linear concept - but time dilation challenges that perception. Just as gravity pulls things down, time simply moves forward at a constant, unwavering ...

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.

Jarred Roberts receives funding from NASA. My telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, ...