Edwards’s remarks about Steady State and Big Bang theories of the universe had stimulated Clifford’s curiosity with regard to cosmological models. Accordingly, Clifford applied himself to refreshing his knowledge of the subject. In due course, he was intrigued to discover that, while the weight of observational evidence amassed over the decades strongly favored Big Bang as Edwards had pointed out, a comparatively recent theory of quasars had been published that seemed to threaten seriously one of the traditional pillars upon which the Big Bang model rested.
It was a question of the amount of helium present in the galaxy. Both cosmological models—Big Bang and Steady State—enabled mathematical predictions to be made of how much helium there ought to be.
According to the generally accepted Big Bang model, most of the helium that existed had been produced during the phase of intense nuclear reactions that accompanied the first few minutes of the Bang. Calculation showed that as a consequence of the processes involved, one atom in every ten that went to make up the galaxy would be a helium atom. During the twelve billion years or so that followed the Bang, this amount would be increased slightly by the manufacture of helium through stellar fusion.
On the other hand, the Steady State model, by that time largely discredited, was obliged to assume that all the helium observed had been produced by the fusion of hydrogen nuclei in the interiors of stars. Measurements of such fusion reactions in terrestrial laboratories and nuclear reactors, when combined with the data that had been accumulated through years of astronomical observation, gave a figure for the total rate of helium production for the whole of the galaxy. When this figure was multiplied by the accepted age of the galaxy, the answer provided an estimate of how much helium there should be in total; it came out at about one atom in every hundred.
Here, then, was a relatively clear-cut method of testing the validity of the two models: Big Bang predicted ten times the amount of helium that Steady State did. Many such tests had been performed, all with a high level of confidence. They all gave a result in the order of ten percent. Big Bang, it appeared, passed the test extremely well.
Or so it had seemed before the Japanese theory of quasars was announced and confused the issue. The theory explained the phenomenal amount of energy radiated by quasars as the result of the mutual annihilation of enormous quantities of matter and antimatter. Quasars were viewed as the scenes of cosmic violence on an unprecedented scale, where armies of matter and antimatter numbering billions of solar masses each were locked in a ruthless battle of extermination, destined to continue until one or the other adversary was completely eliminated. Eventually a galaxy would condense out of the ashes of the conflict—a normal galaxy or an antigalaxy, depending on the flag of the survivors.
The detailed mechanics of the process as presented by the two Japanese cosmologists involved the production of large amounts of helium as a by-product. That put a new light on the question of cosmological models.
Because of their enormous distances, quasars provided, in effect, a window into the past—a view of events that had taken place billions of years previously. If the Japanese theory was correct, the Milky Way Galaxy too would have been formed from the debris of a cataclysmic quasar event that had occurred during some earlier cosmic epoch. The quasar had burned itself out, but its residues still remained—including the helium.
So that could be the answer. Maybe the observed amount of helium didn’t require the primordial inferno of a Big Bang to explain it at all. At least, now there was an alternative explanation that needed looking into.
Even if the theory eventually came to be fully substantiated, vindication of the Steady State model would not follow automatically. For one thing, the time-window provided by long-range astronomical observations revealed an evolving universe—evolving from a population of quasars to a population of galaxies—and not one that remained unchanging in its general appearance throughout the whole of time, as seemed to be demanded by a Steady State definition; indeed, the new theory itself required an evolutionary sequence.