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 ...

Intuitively, we know what time is, but try to explain it, and we end up tying our minds in knots. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

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 ...

Two blind spots torture physicists: the birth of the universe and the center of a black hole. The former may feel like a moment in time and the latter a point in space, but in both cases the normally ...

If you wave your hand in front of your face, you won’t notice anything particularly interesting. Perhaps a gentle waft of air against your cheek – that’s about it. No epiphany. No major sign that ...

Contemporary physics has learned to describe the universe with unprecedented precision. Yet when it tries to say what time is, it stumbles again and ...

Interstellar comet 3I/ATLAS made its closest approach to Earth early on Friday, Dec. 19. While it didn't come close enough to ...