In the beam of light emitted by a laser pointer, photons travel predominantly along one direction and the beam is therefore said to be collimated. The electric field carried by these photons is ...

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 ...

This course introduces the quantum mechanical concept of angular momentum operator and its relationship with rotation operator. It then presents the angular momentum operators, their eigenvalues 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 ...