Doppler

How to spell doppler

7 letters · 2 syllables

How to pronounce doppler

Say the part in capitals loudest.

What does doppler mean?

1. adjectiveRelating to the change in observed wave frequency caused by motion of the source or observer, or to instruments that use it.

Doppler in a sentence

• The doppler effect explains why a passing siren seems to drop in pitch.

• Forecasters rely on doppler radar to measure how fast a storm is moving.

Where does doppler come from?

Language of origin: Germanic

This word is an eponym taken directly from the surname of Christian Doppler, an Austrian physicist who lived from 1803 to 1853. In a paper presented in Prague in 1842 he described how the observed frequency of a wave changes when its source moves toward or away from an observer, an idea now called the Doppler effect. The surname itself is of German origin and was simply his family name; it carried no special scientific meaning before he gave it one. Over time the name became a common attributive label attached to instruments and techniques that exploit this frequency shift, such as Doppler radar and Doppler ultrasound. Because it preserves a German personal name, the spelling keeps the double p that English speakers sometimes drop by mistake.

How the word is built

• Doppler (surname of physicist Christian Doppler), used attributively