The late Tom Van Flandern once said, “If you want to find evidence refuting Big Bang Theory, just point a telescope at the sky!”
Two observational stanchions support contemporary cosmology: Hubble redshift and microwave background radiation. The first is used to describe the systematic expansion of the Universe, and the second is put forward as a radiation image of the Universe as it was very soon after Big Bang. Because redshift and radio noise are things that are seen to exist, much of the discussion on cosmology centres on one or both of them.
More esoteric aspects of Big Bang Theory, like multi-speed inflation, and very technical, complex issues, for example nucleosynthesis and the evolutionary development of matter and structure as we see it today, are left to the devices of specialists. Observational astronomers and astrophysicists using empiricism to derive their explanations of the cosmos would tend to concentrate on the first two tenets of cosmology, and in discussing the subject would lean towards redshift because the microwave background requires horrendous mathematical manipulation before it makes sense in the BBT context.
Everything in this model of the Universe depends critically upon scale. This is one of the subtlest machinations in Big Bang theory, and tends most often to be avoided in discussions of universal expansion. I would imagine we all know what redshift is in principle, because we all associate it with Doppler shift in sound, something we experience in our daily life. A screaming ambulance passes in the background, and we know without seeing it when it is moving away from us because the pitch of the siren drops. The departing ambulance stretches the sound waves and audibly lowers the sound frequency.
When Edwin Hubble first found some progressive correlation between the distance to nearby galaxies (well established in some cases, completely obscure in others) and the overall redshift of the light coming from them, he was puzzled. Not so the cosmologists who heard of his discovery. For reasons that will soon become clear, they made the inference that it was caused by the Doppler effect. In other words, they concluded that the galaxies were moving away from us, that the further they were, the faster they were going, and that the rate of recession therefore also told us how far away the object is. Or was. This is generally referred to as the Hubble Law. But it was observationally inconclusive, and Hubble himself remained deeply sceptical.
It is important that we carefully examine Hubble’s own interpretation of this apparent redshift relationship. As is my wont, I shall now paint in a brief historical perspective. For Edwin Hubble, it started in 1924, with his observation of Cepheid variables in some of the so-called spiral nebulae. It was thereby established that these nebulae were in fact stellar systems in their own right, located far outside the Milky Way, and this constituted the advent of extra-galactic astronomy. Then came The Bomb! In 1929, Dr Hubble discovered that for galaxies in his field of view, that is, fairly local, the fainter they are, the higher the redshift.
From the outset, however, data patterns were indistinct and tenuous. Hubble’s original redshift data were described by Nobel Laureate Steven Weinberg as leaving him “perplexed how he (Hubble) could reach such a conclusion—galactic velocities seem almost uncorrelated with their distance, with only a mild tendency for velocity to increase with distance.” Hubble himself remained steadfastly unconvinced that the Doppler effect correctly explained his observations. Dr Hubble was at pains to declare quite emphatically that no universal principle was revealed by his measurements, and that they were in any case ambiguous.
In 1935, he and Richard Tolman warned us, “the possibility that red-shift may be due to some other cause, connected with the long time or distance involved in the passage of the light from the nebula to observer, should not be prematurely neglected.” In a paper for the Astronomical Society of the Pacific in 1947 (some 20 years after his discovery), Hubble stated, “…it seems likely that red-shifts may not be due to an expanding Universe, and much of the speculation on the structure of the universe may require re-examination.”
And so it remained. Edwin Hubble developed a consistent cosmology that began with the exciting but untested theoretical supposition that the entire Universe was expanding away from a beginning in time, and therefore necessarily “finite but unbounded”, but soon he was forced to abandon that position in its entirety. Dr Hubble developed as a consequence of his observations a description of the cosmos that was both infinite and static, the diametric opposite of his original model and the current Standard Model of Cosmology.
Professor Andre Assis of the University of Campinas in Brazil presented a paper at the Second Crisis in Cosmology Conference in the USA in 2008, entitled Hubble’s Cosmology: From a Finite Expanding Universe to a Static Endless Universe . It was co-written with his compatriots M.C.D. Neves and D.S.L. Soares, and gives a scholarly insight into Hubble’s philosophy, based on a thorough examination of his published works. I urge those interested in the sociology of scientific politics to read it.
Hubble, assisted by his friend and colleague Richard Tolman, suggested a test for the redshift/velocity relationship, the now well-known number effect. The following quotes from Hubble’s writing (in his 1936 book The Realm of the Nebulae, commencing page 193) are drawn from this paper:
“Apparent luminosity is measured by the rate at which the quanta reach the observer, together with the energy in the quanta. If either the energy or the rate of arrival is diminished, the apparent luminosity is diminished. Red-shifts reduce the energy in the quanta whether the nebulae are stationary or receding. Thus an ‘energy-effect’ may be expected, regardless of the interpretation of the red-shifts. The rate of arrival (i.e., the number of quanta reaching the observer per second) is reduced if the nebulae are receding from the observer, but not otherwise. This phenomenon, known as the ‘number effect’, should in principle provide a crucial test of the interpretation of red-shifts as velocity-shifts.”
And indeed it has. To the best of my knowledge, no application of this test has succeeded in verifying the velocity interpretation, despite numerous attempts. On the other hand, at least two published studies (Andrews, 2006 , and Lerner, 2006 ) have shown quite conclusively that the number effect in fact falsifies the expanding Universe model, and cosmological redshift is thereby released from its velocity cage to be freely interpreted without bias. It’s a great pity that Edwin Hubble did not live long enough to see the observational proof of his vision, because he might yet be exonerated of the blame that I and others heaped upon him.
He carried the static, endless model with him to the end. Hoyle, Burbidge, and Narlikar, in A Different Approach to Cosmology , recount Hubble’s concluding uncertainty: “In his last discussion of the observations, Hubble in the George Darwin lecture at the Royal Astronomical Society in 1953, a few months before he died, gave the first results obtained using the 200-inch telescope…Sandage has pointed out that using the ‘no recession factor’ (meaning no correction for the number effect), Hubble was still doubtful if the expansion was real.”
Sadly, it seems that if the discoverer of cosmological redshift was doubtful, the same could not be said of certain interested bystanders. The eager cosmologists waiting in the wings were, true to form, not in the slightest doubt whatsoever that the whole Universe was flying apart, and that Hubble had proved it. What a great shame that our memory of Dr Hubble is almost indelibly tainted by their undue haste to make a point.