It’s understood that disparate velocities do not effect the particle speed of a photon that reaches an object from another. My question is does relativity disparity effect the wavelength of the photon as that reaches the object?
doppler shift is observed. hence we see red shift in receding galaxies due to the expansion of space.
ChrispenEvan said:
doppler shift is observed. hence we see red shift in receding galaxies due to the expansion of space.
that’s not a relativistic effect though
ok, time dilation is included
https://en.wikipedia.org/wiki/Relativistic_Doppler_effect
Locally, all photons have the same speed, but their energy differs.
Postpocelipse said:
It’s understood that disparate velocities do not effect the particle speed of a photon that reaches an object from another. My question is does relativity disparity effect the wavelength of the photon as that reaches the object?
mollwollfumble said:
Postpocelipse said:
It’s understood that disparate velocities do not effect the particle speed of a photon that reaches an object from another. My question is does relativity disparity effect the wavelength of the photon as that reaches the object?
To summarise the answer given by Crispen and DV, the answer is “Yes”.
or, more correctly, no
Dropbear said:
mollwollfumble said:
Postpocelipse said:
It’s understood that disparate velocities do not effect the particle speed of a photon that reaches an object from another. My question is does relativity disparity effect the wavelength of the photon as that reaches the object?
To summarise the answer given by Crispen and DV, the answer is “Yes”.
or, more correctly, no
Compromise with a maybe
Yes? No? Maybe? I’m going to give you an answer that I know to be 100% correct:
I don’t know…
I thought red shift was due to stretched space time, not differences in relative velocity within space-time,but then again I’m as dumb as a post.
Phil gives a good summary
Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. Another kind of redshift is cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields.
I was gratified to be able to answer promptly, and I did. I said I didn’t know. — Mark Twain
Thanks. Had a bit of insomnia going on and forgot the relevant measurement…..