God In The Equation Read online

  More than Bondi and Gold, Hoyle labored to show how the steady state theory could fit in with general relativity. In order to keep the universe steady and unchanging, he invoked a novel scientific process strongly reminiscent of Lambda. Operating in the tradition of Einstein, Hoyle added an extra term to the relativistic equations to keep everything in proper balance. Hoyle's new term, which he called C for “creation,” sat in the same spot in the equations where Einstein had placed Lambda and produced an analogous outward force. “It is this creation that drives the Universe,” Hoyle wrote. The difference was that C produced matter, whereas Lambda produced energy to counter the pull of gravity. Again like Lambda, C was a fudge factor, a mysterious element designed to reconcile a beautiful cosmological theory with the observed properties of the universe. Hoyle had criticized the big bang models because they needed a fine-tuning of Lambda in order to get around the age problem, yet now he found himself in the same boat with his rivals. In the search for a comprehensive understanding of the universe, they all invoked a divine hypothesis and prayed that observation would affirm their faith. Through some mathematical juggling, Hoyle argued that the spontaneous creation of matter didn't violate conservation laws after all. In technical terms, he proposed that the C-field had negative energy, so that the increasing strength of the field exactly equaled the mass of the newly created matter—remember that mass and energy are equivalent according to Einstein's equation E=mc2. It still sounded like cheating, but from a formal perspective Hoyle could insist that the scales were balanced.

  Steady state cosmology attracted a number of followers, especially in England. William McCrea, a prominent British astronomer and the secretary of the Royal Astronomical Society, actively endorsed the new theory and helped expedite the publication of Hoyle's first paper. McCrea hoped that a complete understanding of the C-term would lead to the unification of quantum physics and relativity, Einstein's unrealized lifelong dream. Hoyle, Gold, and others continued to refine their models. They tried to show that the steady state could account for the formation of galaxies more naturally than the big bang could. From the start, Hoyle considered galaxy formation one of the big bang's greatest weaknesses. “This big bang idea seemed to me unsatisfactory even before detailed examination showed it leads to serious difficulties. . . the really serious difficulty arises when we try to reconcile the idea of an explosion with the requirement that the galaxies have condensed out of diffuse background material,” he wrote. He also worked to show that stars alone could account for the origin of all the chemical elements. Gamow's papers on nuclear reactions in the early universe bolstered the credibility of the big bang, but his cosmic fireball could not account for the origin of the heavier elements. Hoyle's studies suggested that massive stars and supernova explosions might be able to do the job. So for a time, the arguments from nuclear physics lent some credibility to the steady state.

  Nevertheless, the steady state theory encountered considerable resistance on sci/religious grounds. Many scientists agreed when Gamow derided it as “artificial and unreal.” He was more comfortable placing the moment of genesis in the distant past, where it wouldn't interfere with our modern, rational world. Consciously or not, cosmologists had been conditioned by the Bible (and by nearly every other creation mythology) to accept miraculous events that happened at very early times but that no longer operate today. In impish style, Gamow acknowledged the mystical nature of this work but used it to poke fun at Hoyle's complicated mechanisms for synthesizing elements in stars. In a retelling of the story of creation, entitled “New Genesis,” Gamow concluded: “And so, with the help of God, Hoyle made heavy elements in this way, but it was so complicated that nowadays neither Hoyle, nor God, nor anybody else can figure out exactly how it was done. Amen.” One scientist dispensed with such evasive sarcasm and openly admitted he disliked the steady state model because of its conflict with the doctrines of old-time religion. Milne, Einstein's outspoken critic, was offended by a theory in which the universe came into existence not in a single glorious moment of creation, but in an endless succession of humble field fluctuations. “This is not a Providence that I for one could worship as God; and to do the authors of the theory justice, they do not believe or assert that any transcendental omnipotence is behind the simple acts of creation at all,” he wrote in 1952.

  At the same time, Alpher and Herman had continued to refine their big bang calculations, aided by a newfangled tool called the computer. By 1953 they claimed they could trace the physical history of the universe back to the first ten-thousandth of the first second of existence. But no matter how much the big bangers couched their theory in abstract terms, talking about particles and fields, they kept running into reminders that the new sci/religion was treading on territory long claimed by old Judeo-Christian belief. Hoyle, a staunch atheist, repeatedly harped on this connection. In his 1950 book, The Nature of the Universe—largely a compilation of his BBC presentations—he attacked Christian dogma and linked it with the creation mythology of the big bang. Pope Pius XII unintentionally strengthened Hoyle's case. In a November 1951 address before the Pontifical Academy of Sciences, Pius XII praised the big bang in great detail. “With that concreteness which is characteristic of physical proofs, it has confirmed the contingency of the universe and also the well-founded deduction as to the epoch when the cosmos came forth from the Hands of the Creator. Hence, creation took place. We say, therefore, there is a Creator. Therefore God exists,” he pronounced. He also gushed that “present-day science, with one sweep back across the centuries, has succeeded in bearing witness to the august instant of the primordial Fiat Lux.” Hoyle relished this association between the big bang and the most prominent figure in Catholicism. “I don't take much stock in faith,” Hoyle said, tarring the pope and the big bang with the same brush. But Gamow was not the least bit perturbed. Rather, he was so entertained by the papal response that he cited it in a scientific paper published in Physical Review. He also sent the pope a copy of one of his recent popular articles on cosmology. Other big bang supporters felt embarrassed by the theory's chummy new association with organized religion. Lemaitre vehemently reaffirmed that his cosmology was completely independent of any “metaphysical or religious question” after the pope weighed in. Through a connection at the Vatican Observatory, Lemaitre persuaded Pius XII that calling on astronomy to support theology harmed both sides.

  Lemaitre's concerns were well founded. At the most basic level, the papal address looked like another retreat on the part of old-time religion. Alpher and Hermann had limited the time available for God's act of creation to the first ten-thousandth of a second. Everything after that belonged to science. Even more problematic was the pope's implicit attempt to bolster the credibility of Catholicism by appealing to the authority of science. If science carried weight in this matter, what about all those other matters—the existence of heaven, the resurrection of Christ, transubstantiation—in which it not only provided no support for the Bible, but flat-out contradicted it? The appeal to science leads to deism, not Catholicism. And the evolving truths of science make a very shaky foundation for any ancient religion. Unlike the pope, science never claimed to be infallible. Quite the opposite: the whole source of its power is its fallibility or, more precisely, its falsifiability. Right now cosmology looked good because it implied a single moment of creation, but another observation or a new theory could lead to a different picture of the universe. Sure enough, current ideas about multiple universes undercut the 1950s notion of a single moment of creation. By its very nature, sci/religion does not support the leap of faith that the pope was seeking. He had to emphasize, “We say, therefore, there is a creator,” because the only true basis for his kind of belief is belief itself. Pius XII never again made a connection between cosmology and biblical creation.

  As for that other outspoken authority on science and God, Albert Einstein, he felt ambivalent about the competing cosmological models. To Einstein God was the embodiment of natural law, not th
e willful Creator of the universe. Not surprisingly, therefore, he always avoided explicit discussions of creation. He thought he had evaded creation entirely in his 1917 paper, of course. When he developed the expanding Einstein-de Sitter cosmology, he never spoke about what happened at the start of the expansion. Even when he discussed cosmology with Gamow, he was interested only in the physics of the early universe, not in the moment when it all went bang. In one of the last interviews of his life, given to Canadian astronomer Alice Vibert Douglas in 1954, Einstein dropped the mask somewhat. He expressed little appreciation for the steady state model, feeling that the universe could have come into existence only through a single formative event. He likewise rejected Milne's kinematic relativity, which he regarded as clever but theoretically flawed. But Einstein did not care for Lemaitre's primeval atom, either, and seemed weary of the endless speculation that his 1917 paper had unleashed. “Every man has his own cosmology, and who can say that his own theory is right?” he reflected.

  In a sign of just how deeply the new sci/religion had penetrated the popular culture, the cosmology battles took on cold war overtones. When Hoyle assailed the dogmatic nature of the big bang, he associated it not only with Catholicism, but also with nationalism and communism, which, like the big bang, assumed a progressive direction to history. The charge was rather odd considering that Gamow, the high priest of the big bang, detested Soviet ideology and had fled to the West at his first opportunity. Never one to back away from a tussle, Gamow countered with intimations that the steady state was more acceptable to Soviet political theorists, who rejected the notion of a cosmic beginning as the product of idealistic and theistic Western thinking. Indeed, the nominal position of the Communist Party was that the universe is infinite in extent and endless in duration. Pope Pius XII's endorsement merely solidified the perception in the Soviet Union that the big bang model was inherently religious and reactionary. During the 1940s and 1950s, however, the government of the Soviet Union frowned upon any physical theory that attempted to describe the whole universe, dismissing this as bourgeois materialism. As a result, Russian astronomers generally avoided cosmology entirely. The continuous creation process in the steady state theory was, on the whole, just as offensive to Soviet theoreticians as the perceived biblical echoes in the big bang.

  While these arguments made for entertaining intellectual theater, the fate of the two competing cosmologies cried out for more of the lifeblood of sci/religion, empirical evidence—and at first, there wasn't a whole lot of it forthcoming. Theory had skipped disconcertingly far ahead of observation and remained there until the mid-1960s. Bit by bit, however, the signs began to look bad for the steady state. Hoyle dismissed the early contrary findings as uncertain and possibly biased, which some of them certainly were. He also had no qualms about modifying the theory. He experimented with a version in which matter and antimatter are created equally, or one in which new matter erupts into existence so energetically that it emits a birth cry of X rays. In later years he considered that the universe might contain large irregularities or might have formed in an ongoing series of little bangs. Hoyle's attitude was always one of exploring all possible explanations. Gold and Bondi, on the other hand, rigorously believed in the primacy of the theory that the universe remained eternally the same. Like Einstein's stationary universe, their steady state model proved an easy target of attack, but it lacked the all-encompassing theoretical power that had made Einstein's cosmology such a revelation to the followers of sci/religion.

  If the steady state were correct, at least in its Bondi and Gold version, the cosmos should have always expanded at the same rate. The big bang, in its simplest form, implied a universe forever running down from its initial state. In the 1950s, Humason and Sandage examined galaxies at a wide range of distances to see which description was correct. After much agonizing analysis, they thought they saw signs of cosmic deceleration. If true, it contradicted the most basic assumption of the steady state, although the enormous uncertainties in their data left plenty of room for doubt. (In fact, astronomers in the 1990s found a cosmic acceleration, the exact opposite of what Humason and Sandage claimed in the 1950s.)

  Another, far more clear-cut prediction of the steady state model was that all parts of the universe should be largely the same. They should all contain a mix of old galaxies and young ones created from new-formed matter, with no net evolution and a consistent average age throughout. Yet observers noted that no galaxies looked much older than the Milky Way's oldest stars, nor did any look much younger. “It was very clear to me from the beginning that the steady state was wrong. There was never a question in my mind, because having been a student of Baade's. . . it was obvious that all galaxies were the same age as the oldest stellar content. And that could not be in a steady state universe,” Sandage explained. Still, this line of evidence against the steady state was inconclusive and somewhat impressionistic. The more devastating blows came from the new field of radio astronomy.

  After World War II, the radar and radio technologies developed for military use began to find applications in a peaceful conquest. Astronomers started using the much improved antennas and detectors to explore the universe in a new way, picking out radio emissions coming from various parts of the sky. Some of these sources were obviously familiar objects, such as the sun. Many more were scattered across the sky and were presumed to be galaxies or other distant objects that for reasons unknown uttered a great deal of radio noise. Nobody at the time knew where or what those sources were. Scientists have since identified them as massive galaxies whose emissions are probably powered by gas funneling into a black hole containing as much mass as a billion suns.

  In 1954, Martin Ryle at Cambridge University, one of the pioneers of radio astronomy, had a brainstorm. He realized that these radio sources could distinguish between the rival cosmologies. If the steady state were correct, the sources should be distributed equally through space, with the result that faint ones should outnumber bright ones following a simple, geometric pattern. In reality, Ryle soon found there are many more faint sources than one would expect from a uniform distribution, indicating that the radio sources are much more numerous at great distances than nearby. An evolving, big bang universe allows for such changes. The steady state does not. Ryle, who had already feuded with Gold, happily reported that “there seems no way in which the observation can be explained in terms of a steady-state theory.” Gold doubted Ryle's results, telling Hoyle, “Don't trust them, there might be lots of errors in this and it can't be taken seriously.” But Hoyle couldn't brush aside serious evidence from his university colleague, no matter how much he disliked Ryle's motives in performing these observations. Instead he tinkered with the steady state model, allowing that the universe might be uniform after all. If it contained huge blobs that were all created at the same time, then large regions of galaxies might all have the same age and he could explain why radio galaxies seemed to cluster at large distances. Such a universe could still average out to a “steady state” over very large distances or very long times. To the unconverted, Hoyle's arguments sounded like special pleading. By the early 1960s, Ryle's data were good enough that many astronomers considered them a decisive blow to the steady state cosmology.

  But the worst was yet to come for Fred Hoyle and company. Back in 1948, when Alpher and Herman had speculated that radiation from the fierce heat of the big bang might still ricochet about the cosmos, they didn't regard the calculation as anything more than a curious statistic. They never suggested that anyone look for this relic of creation, nor did Gamow, even though he recalculated the background temperature of the universe several times in the following decade. Starting around 1963, Robert Dicke at Princeton University arrived independently at the same conclusion. Dicke was at the time fascinated by the possibility of an oscillating universe, and he wanted to know how much radiation would be left over from each outward bang. His calculations told him that the radiation, stretched and cooled by billions of years of cos
mic expansion, would mostly be in the form of microwaves—short-wavelength radio waves like those used for UHF television broadcasts or, later, for heating food in a microwave oven. He realized that existing microwave detectors were sensitive enough that he could actually test his prediction. James Peebles, a former student of Dicke's who had also settled at Princeton, reworked and refined Dicke's temperature estimate, while two other colleagues went to work building a foot-wide microwave antenna and set it up on a rooftop, hoping to eavesdrop on the echo of the big bang. While Dicke and Peebles fussed with this experiment, a pair of young radio astronomers at nearby Bell Labs in Holmdel, New Jersey, puzzled over a seemingly unrelated problem. Arno Penzias and Robert Wilson were refurbishing a giant, horn-shaped radio collector originally used to pick up signals bounced off Echo, one of the first American satellites in orbit. While calibrating the instrument, the two men were distressed to find some persistent radio noise that they could not eliminate. They took the electronics apart and put them back together. They waited for radiation to die down from a 1962 high-altitude nuclear test. They cleared out a pair of pigeons and some pigeon droppings from inside the antenna, thinking that the body heat from the birds might be the problem. “We were really scratching our heads about what to do,” Wilson wrote. Dicke heard of their difficulties and realized that the fault lay not in the telescope, but in the stars. The Bell Labs scientists had a hard time digesting Dicke's explanation of their instrument noise. “Although we were pleased to have some sort of answer, both of us at first felt a little distant from cosmology,” Wilson recalled. But Penzias and Wilson had stumbled across the first observational evidence of the big bang. All of Gamow's work on how elements formed in the early universe was an after-the-fact explanation. The microwave noise was something else again. It did what the pope's exhortations could not: it made creation real.