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 ...

Scientists have detected the Doppler effect — a quirk of physics that makes an ambulance's siren change pitch as it drives by — on the scale of a single molecule. The Doppler effecthas been understood ...

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 ...

What if the speed of light is a constant only most of the time? What if gravity sometimes pushed instead of pulled? Scientists are increasingly asking what would seem like far-out questions regarding ...

A twist on the physics that cops use to clock speeding drivers can determine how fast an object is spinning. The approach could be used to protect wind turbines from damaging winds, learn about ...

Physicists have generated a lot of excitement in recent years by dreaming up specially structured materials with novel applications like invisibility cloaks. What’s more, some of these “metamaterials” ...

Blackmore's lidar system can detect the velocity of pedestrians and vehicles: objects moving away from the vehicle are in yellow or red, those moving toward it appear blue. This morning I got a ...

MADISON — What if the speed of light is a constant only most of the time? What if gravity sometimes pushed instead of pulled? Scientists are increasingly asking what would seem like far-out questions ...