(May 4, 2021 at 8:47 am)onlinebiker Wrote:(May 3, 2021 at 5:40 pm)HappySkeptic Wrote: When a sound source is moving toward you, its frequency or pitch is higher (think soprano instead of bass).
When a sound source is moving away from you, its frequency (or pitch) is lower.
You also get a higher volume when a sound source is close to you. If someone hits a bell right in front of you, its louder than if it is down the street.
The two effects together explain the sound of a fire engine coming toward you and going away.
No.
Doppler effect is obsevable only from an observer' s point of view.
That is - the audio frequency of the moving object (like a train coming towards you) in reality is constant - but APPEARS to the observer as ascending in frequency.
The same can be observed by a moving observer and a stationary source of sound.
Trust me - I KNOW Doppler effect.
I was taught it back in 1981 when I was a Coast Guard Radioman - and SARSAT went on line. SARSAT uses Doppler shift - observing an EPIRB on the ground and by measuring the intensity of the doppler shift can calculate two possible positions of the EPIRB transmitter on either side of the satellite' s polar track....
radio waves do not propagate by interaction within any medium. so there is no unique frame with which to describe frequency of radio wave. each observer is his own frame of reference. sound wave are different, it propagates by means of a medium. interaction between particles of the medium defines the audio wave. So the medium forms a special frame of reference for audiowaves. When measured against that special frame, audiowaves emitted by an object moving with respect to the medium of its propagation definitely has a different frequency and amplitude depending on the direction of propagation.
