What is the Doppler?

DrPhy

I know its to do with the drop of frequency when the object that is making the noise passes you, but what exactly is it? I dont know much about it.

Doc Al

See: Doppler Effect

davenn

not just the drop in freq, but also the increase in freq as the object is moving towards you

Anyway reading Doc Al's link should clarify things for you

Dave

krd

Does anyone know much about how atoms are effected by the Doppler effect as they move......or as something moves towards them?

I've been trying to visualise it. Like as a photon approaches an atom, the atom seems flat to the photon. I've been thinking about electrons too.

Simon Bridge

Sounds like a separate thread there krd.
How about starting one and pinging me to reply?

Hint:
when you use length contraction - all of space gets flattened, not just objects in space.

alextx

Here is an animation demonstrating the Doppler effect:
http://youtu.be/ZRGg7e9b5wY

Simon Bridge

Good find alextx - wikipedia also has a bunch of them.