Fortunately for physics...light is not nor has ever been observed to be a photon.
Albert made this fantasy up in 1905 to pave the way for his other relativity fantasy
later that year. (Ie One fantasy can’t survive without the other.)
But unfortunately in 1929, the low IQ physics community having just ditched one
nonsense theory(aether) for another (photon +relativity ), were not prepared to accept
that Hubbles redshift/distance relationship just invalidated all of Einsteins nonsense.
Because if they did admit that the *empirical* observation of light losing frequency over
distance ruled out the fantasy of the photon which couldn’t change frequency over
distance....then all the con artists of the day would lose their well paid university jobs
and have to return their nobel prize money.
At which point to cover their butts, they invented a new field of physics. BBT.
Their excuse was that those who stuck with a non expanding model couldn’t
explain how light “lost” energy over distance! Citing their absurd argument
that a “photon” of one frequency is not the same energy as a “photon”
of 1/2 that frequency.What a load of nonsense.
Just because light loses frequency over distance does not mean that it has
to lose energy over distance. Dont forget that light isn’t a photon and
that wave energy emitted between 100-200nm is equal to the same
energy when redshifted to 200-400nm. How? Simple
The redshifted light is twice the range in manometers than the emitted
light. So it’s energy per frequency is halved...but it’s total measured
range in nm is doubled. And no relativistic photon fantasist can prove otherwise.