Red shift and the train thought experiment

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SUMMARY

The discussion centers on the omission of "redshift" and "blueshift" in the train thought experiment used to teach relativity. Participants agree that these concepts are not necessary for the basic understanding of the experiment, which primarily focuses on the differences in measuring light and sound. The key distinction highlighted is that while the observer on the train must account for the train's speed when measuring sound, this adjustment is not required for measuring the speed of light due to its invariant nature in a vacuum.

PREREQUISITES
  • Understanding of the Doppler effect
  • Basic principles of special relativity
  • Knowledge of light and sound wave propagation
  • Familiarity with the concept of invariant speed of light
NEXT STEPS
  • Explore the implications of the Doppler effect in different media
  • Study the principles of special relativity in detail
  • Investigate the concept of invariant speed of light in various scenarios
  • Examine real-world applications of redshift and blueshift in astrophysics
USEFUL FOR

Students of physics, educators teaching relativity, and anyone interested in the fundamental concepts of wave behavior and relativistic effects.

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It seems there is usually no mention of "redshift" when train thought experiment is used to teach relativity. Is there a reason for not bringing redshift (blueshift) into the experiment?
 
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It isn't brought in because it isn't needed. Why do you think it is?
 
russ_watters said:
It isn't brought in because it isn't needed. Why do you think it is?

Because (I thought?), there's mentioned made in this experiment on how the measurement of light from a train is different than that of the sound from a train. But, it seems (?) they both have the doppler effect.

Is then the important difference that the person on the train has to add the speed of the train when measuring the speed of sound but not when measuring the speed of light?
 

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