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 ...

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 ...

Schematic of a single photon with zero angular momentum (green) splitting into two photons (red) with either zero or opposite angular momenta (sketched through the spatially varying color), which adds ...

Ars Technica has been separating the signal from the noise for over 25 years. With our unique combination of technical savvy and wide-ranging interest in the technological arts and sciences, Ars is ...

Optical vortices are currently one of the most intensively studied topics in optics. These light beams, which carry orbital angular momentum (OAM), have been successfully utilized in the visible and ...

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 ...

Since energy is conserved (the gravitational force is conservative), we can use the work/energy equation to determine the speed of the satellite as a function of the distance R from O to P. Since the ...