This puzzle is known as the problem of time, and it remains one of the most persistent obstacles to a unified theory of ...

Time feels like the most basic feature of reality. Seconds tick, days pass and everything from planetary motion to human memory seems to unfold along a single, irreversible direction. We are born and ...

Most physicists doubt that time exists. On this page 40 years ago, we published scientific ‘proof’ of time being illusory. We pointed out that none of the equations of physics, from Newton’s laws to ...

Time-dependent driving has become a powerful tool for creating novel nonequilibrium phases such as discrete time crystals and ...

In this video, I explain why some reactions explode while others cool, exploring the root cause of chemical energy. I discuss the chemistry behind endothermic and exothermic reactions, which involves ...

A comprehensive developer guide to implementing secure authentication in modern applications. Covers OAuth 2.0, OIDC, ...

A study links graying hair to stem cells getting stuck, unable to color new hair growth. Stem cells travel back and forth within compartments, but when they get stuck in one compartment, they cannot ...