Pluto and Charon don’t behave like a typical planet and moon system. Instead of Charon orbiting inside Pluto’s body, both objects orbit a point in space between them called the barycenter. That’s why ...

Molten sodium is one of the most reactive and dangerous metals you can work with — and spinning it into a glowing sphere makes it even more extreme. This experiment looks like something from a sci-fi ...

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 ...