> Tired Light Is a hypothesis that, as a sole or primary explanation of observed redshifts of galaxies, has been thoroughly debunked in the scientific literatu

> Tired Light Is a hypothesis that, as a sole or primary explanation of observed redshifts of galaxies, has been thoroughly debunked in the scientific literature. > the intergalactic media is not an electromagnetic vacuum This is true, but it cannot explain the observed data by itself, because the observed data is not "redshifts" by themselves. The observed data is a combination of redshifts, apparent luminosity, and angular size for thousands of observed galaxies. These data have observable relationships that can only be explained by cosmological expansion. If the redshifts were caused solely by dispersion in the intergalactic medium, their relationships with apparent luminosity and angular size would be very, very different. That is a quick summary of the thorough debunking of "tired light" that can be found in the scientific literature over a period of some decades.