How Speed Radars Work

Speed radars can be the bane of your existence. Driving along peacefully, only to have your cruising be interrupted by the flashing of a speed radar or, if you're unlucky, the wail of a siren. How exactly do these curses upon humanity work, then? Magic, obviously.
By magic, I of course mean physics. More specifically, the physics of waves. There are two different types of radar: one that uses radio waves, and one that uses lasers. To begin this discussion, I'd like to first guide you into the wonderful world of wave physics.

Wave Physics

Radar, Part 1

Radar, Part 2