The Sagnac effect, first observed over a century ago, remains central to our understanding of relativistic kinematics and the operational definitions of simultaneity. Fundamentally, this effect arises ...

Researchers have found a way to mimic lightspeed when photographing an object. The method involves stitching together many thin “slices” of light reflecting off the object. Photography—itself a ...

If there is an absolute law in the universe, it’s that nothing can travel faster than the speed of light. For science-fiction enthusiasts, that’s a bit depressing. Space is big, and while the speed of ...