- #36
binbagsss
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PeterDonis said:. The redshift of the photon, as you will see if you do this analysis, then turns out to be, as I said before, the ratio of the scale factor at reception to the scale factor at emission--more precisely, this ratio is equal to ##1 + z##, where ##z## is the redshift.
In previous posts I was trying to establish the definition of red shift, (well the predicted redshift not the lab spectral line observed measurement) and there was no such direct response, other than that of observation. Well if we determine ##k## by the method you described, and ##k## is such that the photon is null, then that is something we are comparing - you used the term red-shift twice above. Somehow it is plausible to immediately state that the 'red shift if the photon' is given by comparing these frequencies, but then you use redshift to refer to ##z## - the only mysterious definition I was pointed to. The important parameter was what I was after, so it's ##k## ? It's so obvious that you can compare frequencies to give the red shift if the photon that you don't even explain this, yet all my questions where pointed toward ##z## ...