Difference between relativistic doppler effect and classical one?

lightconstant
Messages
8
Reaction score
0
When I ask for differences I am not meaning mathematical ones since that it is obvious:
We have a phenomenon p, p can be described by Galilean Relativity (GR)
and by Einsten Relativity (ER).
ER(p)!=GR(p)
The math expression that describes this phenomenon is different.
Then the doppler effect will have another mathematical expression
ER(dp)!=GR(p)
Maybe someone wants to say that GR is like a subset of ER for small velocities in reality It is not It looks similar but It is not, well let us get to the point.
Sound can be described by the classical doppler effect GR(d_e) by addition and substration of velocities though we know the velocity is constant due to the medium.
My question can we do the same with light? can we explain it mathematically with the addition of c+v, c-v?
I hope I have expressed myself clearly, I know c is a constant and We can not add velocities, what am I asking is if by using galilean relativity the doppler effect of light can be explained adding velocities, after all sound has a constant velocity and we add it.
Let us put it another way, is there any physical not mathematical proof, evidence, observation, meaning... that the doppler effect of light is different than the sound one?
Or Is It just the way It is expressed mathematically.
Because I see this applet:
http://webphysics.davidson.edu/applets/applets.html
and the phenomenon looks the same.
 
Physics news on Phys.org
lightconstant said:
When I ask for differences I am not meaning mathematical ones since that it is obvious:
We have a phenomenon p, p can be described by Galilean Relativity (GR)
and by Einsten Relativity (ER).
ER(p)!=GR(p)
The math expression that describes this phenomenon is different.
Then the doppler effect will have another mathematical expression
ER(dp)!=GR(p)
Maybe someone wants to say that GR is like a subset of ER for small velocities in reality It is not It looks similar but It is not, well let us get to the point.
Sound can be described by the classical doppler effect GR(d_e) by addition and substration of velocities though we know the velocity is constant due to the medium.
My question can we do the same with light? can we explain it mathematically with the addition of c+v, c-v?
I hope I have expressed myself clearly, I know c is a constant and We can not add velocities, what am I asking is if by using galilean relativity the doppler effect of light can be explained adding velocities, after all sound has a constant velocity and we add it.
Let us put it another way, is there any physical not mathematical proof, evidence, observation, meaning... that the doppler effect of light is different than the sound one?
Or Is It just the way It is expressed mathematically.
Because I see this applet:
http://webphysics.davidson.edu/applets/applets.html
and the phenomenon looks the same.

Much of what you say is not comprehensible. Classic doppler has no provision for transverse doppler (change in frequency of light emitted by a moving source exactly perpendicular to the receiver). This has been observed with light.

See: http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#Tests_of_time_dilation
 
Thank you PAllen I saw that somewhere but did not know it was only light related,
I guess the phenomenon It is not the same since one has transverse doppler and the other one does not.
Let me look at it and see what is about.
 
Thread 'Can this experiment break Lorentz symmetry?'
1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. The Relativator was sold by (as printed) Atomic Laboratories, Inc. 3086 Claremont Ave, Berkeley 5, California , which seems to be a division of Cenco Instruments (Central Scientific Company)... Source: https://www.physicsforums.com/insights/relativator-circular-slide-rule-simulated-with-desmos/ by @robphy
Does the speed of light change in a gravitational field depending on whether the direction of travel is parallel to the field, or perpendicular to the field? And is it the same in both directions at each orientation? This question could be answered experimentally to some degree of accuracy. Experiment design: Place two identical clocks A and B on the circumference of a wheel at opposite ends of the diameter of length L. The wheel is positioned upright, i.e., perpendicular to the ground...
Back
Top