Everyone knows that time flows in one direction, with events occurring in a sequence. Time’s unidirectionality is linked to ...

We experience the flow of time because it’s a natural outcome of the basic laws of physics. But we may need to build a whole new model to account for gravity’s influence.

Entropy, the amount of molecular disorder, is produced in several systems but cannot be measured directly. A new equation sheds new light on how entropy is produced on a very short time scale in laser ...

The Boltzmann brain hypothesis suggests that our memories are nothing more than unlikely fluctuations. According to the theory, the past and the future don’t exist—only the present does. Researchers ...