We’re all too familiar with the inexorable march of time, but why exactly it flows in one direction remains a mystery of physics. A few years ago Australian physicist Joan Vaccaro proposed a new ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. For most of human history, we kept time by Earth’s place in space ...

Pupil dilation provides a physiological readout of information gain during the brain's internal process of belief updating in the context of associative learning.

Pupil dilation may signal deception. The autonomic nervous system regulates pupil size. Pupil dilation normally indicates an increase in cognitive demand. Liars usually experience an increase in ...

Every week, the readers of our space newsletter, The Airlock, send in their questions for space reporter Neel V. Patel to answer. This week: time dilation during space travel. I heard that time ...