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 ...

Gravity used to be the most dependable rule in the cosmic rulebook, the quiet background force that never changed its mind.

Whether space-time exists should neither be controversial nor even conceptually challenging, given the definitions of “space-time,” “events” and “instants.” The idea that space-time exists is no more ...

Fragments of energy may be the fundamental building blocks of the universe. The theory combines the ideas of particles and waves into a concentration of energy that flows throughout space and time.