A Spin on Doppler
Issued: Thu, 24 Oct 2013 13:39:00 BST
We have a number of devices to measure the speed of an object. We measure moving stars, galaxies, bugs, baseballs, and perhaps most commonly, vehicles caught in speed traps on the highway. Law enforcement uses Radar and LIDAR guns to measure our speed on the highway, but these devices make use of the same principle scientists use to measure how fast celestial objects move – the linear Doppler effect.