Questions and Answers on the Science of Surface Brightness
1) You say the surface brightness of galaxies are the same at all distances? How close are they, exactly? Very close. The average of the surface brightness of all the galaxies at high redshift differ from those at low redshift by less than 2.5%. But the statistical errors are 3%, so the data are completely consistent with no difference at all. Since the surface brightness depends on the square of the radius of the galaxies, the average radii are the same to within 1%. 2) You are testing the hypothesis of a non-expanding universe. Is this the same as the old Steady State theory or the Einstein-de Sitter Universe? No, the Steady State hypothesis did assume expansion, but also hypothesized matter creation to maintain a constant density. The surface brightness data are consistent with a universe that is not expanding at all. The Einstein-de Sitter universe is not expanding, but has a curved geometry. The SEU hypothesis we have tested here is that the geometry of the universe is Euclidean, the same as the space we measure on earth and in the Solar System. 3) When you say “static” universe, does that mean no evolution or change? No, we are referring to its geometry alone—static here means non-expanding. Evolution and change can easily occur, and certainly does occur, in non-expanding space. The earth for example, has undergone enormous geological, chemical, and biological evolution over time, yet it is not expanding. 4) Doesn’t Einstein’s theory of general relativity prove that the universe is expanding? A theory can’t “prove” that the Universe is expanding—only observations can. Our observations indicate that the Universe is not expanding. Even very well-founded theories make predictions that are proven wrong by observation. Maxwell’s theory of electromagnetism, which is still a very well-founded and accurate theory, predicted that atoms would collapse because electrons would spiral into the nucleus. Researchers found that electromagnetic theory had to be extended by quantum mechanics for very small objects. So, since observations indicate that the universe is not expanding, some modifications will no doubt be needed to extend a theory of gravity to very large scales. 5) Doesn’t Olber’s paradox about the dark night sky prove the universe is expanding? No. Again, evolution is obviously occurring in the universe, accelerating as time goes forward. As long as there was a period before any stars and galaxies existed, then the night sky would still be black even with no expansion. Plasmas emitting almost no light could have existed indefinitely before galaxies and stars first emerged. 6) What implications do your results have for dark matter and dark energy? There is no requirement from these results for either dark matter or dark energy, so ordinary matter is the main constituent of the Universe.