Energy of Photon/Red-shift, inflation, acceleration I have a few questions (following a short premise) below. I have been reading medieval philospohy recently and also some about the "Big Bang." What I am struck by is number of assumptions made in both fields. There is a large amount of "revealed truth" in both. The difference being in the "revealed truths" (assumptions/laws) change with observation for physics. The other thing is that nature abhors a vacuum. Thus, reasons are put forward to explain the unexplained. It seems many times that the jump in reasoning outdistances the observed data. Also, understandably, most theories fit the facts, rather than explain the facts. Thus, when new data comes in, existing theories are stretched until broken and overturned by newer theories. Witness the theories about motion of the planets. To the point (and I am sure/hope that many of the points below have already been anticipated), these are some questions that I have not found adequate explanations for: The distances to galaxies are determined using red-shift. The information comes to us through light as transmitted via photons. The distances are calculated using the shifts in absorption lines via Hubble's Law of Expansion (v=HD) and the Energy of Photon (E=hc/wavelength) equations. The question is "does the energy of a photon dissipate through time and/or interference with inter-gallactic matter?" If not, how is this known? If so, could that not account for red-shift? If it is true, then how is it KNOWN what the dissipation would be? Obviously, were any of this to be true then location of far-away galaxies could explained other than by expansion of the universe. If energy does not dissipate then a photon in a space otherwise a vacuum should remain at a constant energy level eternally. Another thing I noticed was the theory of inflation of space-time which is posited to have occured faster than the speed of light (not measurible or falsifiable!). Supposing this to have occured, and having occured early in the universe's history, why the vast emptiness of space? Surely the expansion would have happened evenly within the primordial clouds of "gas" that existed before the formation of galaxies and clusters rather than in quantized/preferred portions of space to allow that clustering. If this were so, then there would be less space between galaxies and the later clusterings would have been into smaller objects. Or assuming that early galaxies had formed, then the expansion would have happened within them as well rather simply between them. This would stretch the galaxies as well as the intervening space-time. Lastly, red-shift is shown to have relativistic effects upon it near a black-hole. Similarly the most distant visible galaxies are receding at near speed of light. Wouldn't the red-shift from those galaxies have a similar relativistic effect upon it? After all, can it be shown that the edge of the visible universe is any different than that of an event horizon? Items near an event horizon undergo an "apparent" time dilation effect due to relative speeds. Would this not be true for galaxies receding nearer the edge of the visible universe? If so, then they should appear to be receding slower than they actually are. Meaning, that galaxies receding from us closer in would appear to be receding faster than they should be relative to the speeds of distant galaxies. This would make the expansion of the universe to appear to have sped up more recently than the long ago expansion. This, if not already accounted for, would go a long way to eliminating dark energy which is used to explain the "repulsion" within a vacuum. It is assumed that the dark energy is constant with volume and that as space time expands it expands with it, thus creating more "pressure" with time. It is not a measurable quantity, but rather just falls out of the equations used with the cosmological constant. Thank you.