What's up in

time

Illustration for thermodynamics
Abstractions blog

Quantum Correlations Reverse Thermodynamic Arrow of Time

A recent experiment shows how quantum mechanics can make heat flow from a cold body to a hot one, an apparent (though not real) violation of the second law of thermodynamics.

Tim Maudlin
Q&A

A Defense of the Reality of Time

Time isn’t just another dimension, argues Tim Maudlin. To make his case, he’s had to reinvent geometry.

Illustration: black, numbered cats crossing a calendar. An extra "13" lurks in the background.
insights puzzle

Solution: ‘Friday the 13th’

There’s more than one good way to bring order to our unruly, seemingly arbitrary calendar.

Illustration: black, numbered cats crossing a calendar. An extra "13" lurks in the background.
insights puzzle

Is It Friday the 13th Again?

How our society defines years, months and weeks can seem frustratingly arbitrary. Can you bring order to our unruly calendar?

Warped time. Olena Shmahalo/Quanta Magazine
Abstractions blog

Quantum Gravity’s Time Problem

The effort to unify quantum mechanics and general relativity means reconciling totally different notions of time.

insights puzzle

Solution: ‘Time Through an LCD Display’

Insights about time’s arrow from a liquid crystal universe.

insights puzzle

Seeing Time Through a Liquid Crystal Display

What insights can an LCD display give us about time’s arrow?

cosmology

A Debate Over the Physics of Time

According to our best theories of physics, the universe is a fixed block where time only appears to pass.

Physics

Quantum Weirdness Now a Matter of Time

Bizarre quantum bonds connect distinct moments in time, suggesting that quantum links — not space-time — constitute the fundamental structure of the universe.