This is a bit confusing. Surely Hubble used the red shift to determine that the Universe seems to be expanding. He very specifically used the Doppler effect to determine that the universe expands. Did he then later go on to claim that the red shift wasn’t due to the Doppler effect at all but to something else. If so surely the whole mathematical reasoning on which his calculations were based would also be skewed? One thing that has been determined is that light (electromagnetic radiation) does obey the Doppler red shift. Proof of this can be founbd in the tiny shift in frequency from the Voyager transmissions.Once, you guys come to understand that Edwin Hubble was correct for the entirety of his life quote):
"If you are believing that my redshift discovery is doppler redshift, then, you are reading too much into my redshift discovery!!"
“Each Deep Space Network site has a highly accurate frequency source that can be tuned to compensate for the Doppler frequency shift caused by relative movement between the transmitting and receiving antennas. Compensation takes into account the movement of the spacecraft, the rotation of the Earth around the sun, and the revolution of the Earth around its axis. Receivers are able to detect frequency shifts that are a fraction of a hertz.” All about circuits.com
What makes things even stranger is that this figure corressponds with a high degree of accuracy toi the Hubble Red Shift.