The Doppler effect is an observed change in pitch (how high or low a sound is) when either the source of the sound or the listener is in motion. Imagine a car, its horn blaring, approaching you as you ...

An increasing number of rheumatologists have access to ultrasound equipment that provide both color and power Doppler modes, which can be used to investigate musculoskeletal and vascular pathologies.

The International Isle of Man TT is a crazy motorcycle race. I mean—it's seriously ludicrous. They ride on public roads (yes, they are closed to normal traffic) such that you get these videos of bikes ...