The change in electromagnetic frequency that occurs when the source of the radiation and its observer move toward or away from each other. The faster they come together, the higher the frequency. The ...

Radar is quite spectacular in telling us exactly where rain is falling by pinging precipitation with radio waves! Our weather radar can determine more than just a storm’s location, but its movement as ...

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 ...

The headline is somewhat of a trick question: of course the effect did exist before the railroads. However, it wasn’t yet defined by the physics of the day, nor was it even noticed before the ...

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A system for measuring speed that is based on the Doppler effect. It is used in police radar systems as well as for measuring the velocity of hurricanes and tornadoes. See Doppler effect. THIS ...