Dark matter seems invisible, but it makes up most matter, and we have evidence that it gives the cosmos its shape. Now ...

For decades, scientists have debated a simple question with a surprisingly complicated answer: could Australia’s extinct giant kangaroos actually hop like the ones alive today? Modern kangaroos are ...

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.