Sound or frequency which sound is would not be relevant unless you had the time to measure the changes in the frequency which would as I said require millions of years on a galactic scale. As the doppler effect requires a minimum of time to observe which when looked for at billions of years in the past requires more time than modern man has existed on earth
Do you need to be two notches?
I have dropped the heads of geniuses who knew before so you can't be first........
Ask around
Since you have an aversion to what you read on the web because you think rogue atheist scientists have taken over, do this:
Get yourself a telescope (A 10 inch reflector would do.) Mount a spectrograph, at the eyepiece. Point it at a bright enough galaxy. Look at the component wavelengths at one edge of the galaxy. The result will be a composite spectrum, probably mostly hydrogen lines. Plot the spectrum on paper. Do the same for the other edge of the galaxy.
You now have two spectra. Notice that the spectra have shifted between the two graphs because of the Doppler effect of light (Not sound!). It happens because one edge of the galaxy is moving toward you and the other is moving away. (Spinning!)
You don't need billions of years. It would take just a few minutes if you have a graphing output on your spectrometer.
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