SR, Doppler effect on rotating disk

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SUMMARY

The discussion centers on the Doppler effect experienced by two observers, O1 and O2, on a rotating disk, as described in Rindler's framework. The observers, positioned at radial distances r1 and r2, utilize adjusted clocks C1 and C2 to synchronize with an inertial frame S. The conclusion is that the frequency ratio of the light signal sent from O1 to O2 is determined by the gamma factors, specifically v2/v1 = γ2/γ1, highlighting the significance of relativistic effects in this scenario.

PREREQUISITES
  • Understanding of the Doppler effect in the context of special relativity
  • Familiarity with Rindler's framework and uniform angular velocity
  • Knowledge of gamma factors in relativistic physics
  • Basic concepts of time dilation and synchronization of clocks
NEXT STEPS
  • Study the implications of the Doppler effect in rotating reference frames
  • Explore the derivation of gamma factors in special relativity
  • Investigate the synchronization of clocks in non-inertial frames
  • Learn about the mathematical formulation of the Doppler effect in relativistic contexts
USEFUL FOR

Students and professionals in physics, particularly those focusing on special relativity, as well as educators seeking to clarify the concepts of the Doppler effect and time dilation in rotating systems.

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Homework Statement



taken directly from Rindler
A large disc rotates at uniform angular velocity ω in inertial frame S. Two observers O1 and O2 ride on the disc at radial distances r1 and r2. They carry clocks C1 and C2 they adjust to keep with clocks time with S, i.e., they have been adjusted so the readings on the agrees with the clock in S. Prove that when O1 sends a light signal to O2 the light is Doppler shifted to v2/v1 =\gamma_2/\gamma_1.

Homework Equations



Well, since it says the clocks have been adjusted, I'm assuming only Newtonian transformations are applicable here, so t=t'.

The Attempt at a Solution



I tried doing this problem in terms of increasing wavelength, but from geometry, I found that each photon travels the exact same distance. Since it says the clocks are calibrated, time dilation isn't relevant either, so I'm guessing I did something wrong.
 
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The question might be a little confusing in the way it is worded. The "adjusted" clocks C1 and C2 are just auxiliary devices for deriving the Doppler shift as observed by unadjusted clocks carried by O1 and O2.

The idea is to first deduce the ratio of ##\nu_2/\nu_1## as measured by the adjusted clocks and then use that to get the frequency ratio that would actually be observed by normal clocks carried by O1 and O2.

From your comments in "the attempt at a solution" I think you might already see what the frequency ratio is for clocks C1 and C2 (but I'm not sure).
 
Ok that makes much more sense, so it's an effect purely based on time dilation ergo the gamma factors. Thanks.
 

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