A frequency shift experienced by an observer whenever a source of waves moves away from or towards the observer is a feature common to all waves — a phenomenon called the Doppler effect. Indeed, ...

Vortex light carries orbital angular momentum (OAM) characterized by exp(ilθ), where θ is the angular coordinate and l is the topological charge (TC) 1. OAM beams have been widely used in a variety of ...

The Doppler shift of sound or light waves from a moving source is familiar to physicists and non-physicists alike. Now, researchers in China and Australia have seen the more exotic inverse Doppler ...

Expertise from Forbes Councils members, operated under license. Opinions expressed are those of the author. Imagine you're at the train station, waiting to catch the northbound train. It's a quiet ...

Indranil Banik does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...