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BrotherBrutha t1_jcoa5jh wrote

>Nothing is intrinsically happening to the energy of the photon.

I think that's my point: the energy of the photon really is reducing (in the case of a cosmological redshift, not a doppler one).

From here :

>Question:.... If light is redshifted in an expanding universe, and this results in photons losing energy, where does that energy go to?

​

>Answer:
..... The short answer, though, is that light loses energy as the Universe expands, and that energy goes into the expansion of the Universe itself, in the form of work.

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RecognitionUnfair500 t1_jcpvyqg wrote

That is false, and is a violation of the conservation of energy. And you seem to be contradicting yourself as well about the change of the energy of the photon

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BrotherBrutha t1_jcpyji9 wrote

It’s not just random blogs that say this though; I’m doing the online ANU EDX astrophysics course at the minute, and it was exactly the explanation they gave (one of the presenters is a Nobel prize winner, so I feel like it’s reasonably trustworthy!). And there are many places that give the same description.

Of course, I appreciate it may not necessarily be the full story, but it at least seems to be more than a daft idea!

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RecognitionUnfair500 t1_jcq3mmq wrote

Is there a chance you may have misunderstood what the presenter said?

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BrotherBrutha t1_jcq4loj wrote

I don’t think so, it was pretty specific. And it matches the answer given in the NRAO link I gave above.

Of course, I could be wrong!

Edit: is it possible that the physics can be interpreted in a bunch of different ways, and some will describe as I have, and some as you’ve done? Perhaps it’s just different conventions in Cosmology vs straight physics?

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