This puzzle is known as the problem of time, and it remains one of the most persistent obstacles to a unified theory of physics. Despite enormous progress in cosmology and particle physics, we still ...

A growing body of theoretical and experimental work in physics is converging on a striking possibility: time, the dimension humans experience as a constant forward flow, may not be a fundamental ...

Ripples in the fabric of space-time called gravitational waves may be the key to solving the Hubble tension — one of the biggest nagging problems in physics.

Conventional crystals are materials in which atoms arrange themselves in repeating spatial patterns. Time crystals, on the other hand, are phases of matter characterized by repeating motions over time ...

For more than a century, physics has treated space and time as the smooth stage on which the universe unfolds, a flexible fabric that bends but never breaks. A new wave of theories is now challenging ...

Shaped by a different biology or culture, other intelligent civilisations – if they’re out there – might understand the universe in a completely different way than we do. Physicist Daniel Whiteson exp ...

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 ...

Einstein–Rosen bridges may reflect a two-directional structure of time that preserves information and hints at a pre–Big Bang universe.

Daryl Janzen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...

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 ...

Space weather has matured from a niche concern to a central pillar of space exploration, national security, and scientific inquiry. In addition to its natural 11-year cycle of rising and falling ...