Surprising as it may sound, 107 years after the introduction of general relativity, the meanings of basic concepts are still being worked out. More than a century after Albert Einstein unveiled ...

When a magnetic material is bombarded with short pulses of laser light, it loses its magnetism within femtoseconds (10 –15 seconds). The spin, or angular momentum, of the electrons in the material ...

Introduction You might have seen figure skaters spinning around quickly and then tucking their arms to spin faster—or opening them to spin more slowly. This happens, thanks to a physics concept known ...

In an introductory physics course, there are three big ideas. There is the work-energy principle, the momentum principle and then the angular momentum principle. I'll skip the work-energy principle ...

Segment 4A: Momentum and Impulse We define the terms momentum and impulse. Segment 4A: Momentum and Impulse We define the terms momentum and impulse. We see the impulse-momentum theorem in action by ...

It's almost always the last topic in the first semester of introductory physics—angular momentum. Best for last, or something? I've used this concept to describe everything from fidget spinners to ...