The Perfect Theory (15 page)

Fred Hoyle arrived in Cambridge in 1933, when Eddington was developing his theory of stars and fighting with the young Chandra over the ultimate fate of heavy white dwarfs. A round-faced, spectacled Englishman, Hoyle had first read Eddington's popular science book
Stars and Atoms
when he was only twelve years old. It was a counterpoint to what he felt was a completely inadequate education during which, as he put it, “I was allowed to drift, more or less.” Yet at Cambridge he flourished, winning a number of prizes as an undergraduate and going on to complete a PhD in quantum physics. By 1939, Hoyle had been made a fellow of St. John's and had won a prestigious research fellowship. He also decided to switch fields, giving up his work on quantum physics to try his hand at astrophysics. Inspired by Eddington's
Internal Constitution of the Stars,
Hoyle decided to think about how stars burn and get their fuel. His later work would be key in understanding how nuclear processes in stars would lead to the formation of heavier elements.

When Hoyle switched fields in 1939, he was also confronted with the start of the Second World War. For the next six years, he would commit himself to the war effort, conducting radar research for the military. Just as the American atom bomb project had attracted the brightest US thinkers, the development of radio-wave technology in radar soaked up some of Britain's brightest talent during the Second World War. An array of dazzling and brilliant ideas were put to practical use for detecting airplanes, boats, and submarines. The legacy of the wartime radar effort is still with us—modern society is awash in radio waves. We use them for radio and television, for wireless networks and mobile phones, for flying aircraft and guiding missiles.

Through his work on radar, Hoyle met two young physicists, Hermann Bondi and Thomas Gold. Bondi, a Jewish Viennese émigré, had, as a sixteen-year-old, attended one of Eddington's public lectures in Vienna. He had felt compelled to move to Cambridge to study mathematics, where, completely enamored of the intellectual environment, he later wrote,
“I wanted to live for the rest of my days.” Coming from an enemy nation, Bondi had been interned in Canada during the initial stages of the Second World War and met Thomas Gold, another Jewish Viennese émigré who had also been enthralled by Eddington's popular books and also studied engineering at Cambridge. Once released from their internment, both Bondi and Gold worked with Hoyle on the war effort. In their spare time, they would discuss the new developments in cosmology and astrophysics, each engaging in his own way: Hoyle was bullish, Bondi was mathematical, and Gold was pragmatic.

When the war ended, all three men returned to Cambridge to take up fellowships at different colleges. Cambridge had become a harsher, emptier place after the war. Quite a few of the faculty had left, drawn by their wartime experience into pursuing careers outside academia. But real estate was at a premium, with rents driven up by the influx of workers during the war effort. Bondi and Gold ended up sharing a house just outside town. Hoyle would often spend the week in their spare room and return to his house in the countryside only on the weekends.

During the evenings, Hoyle would make the most of the extra time with Bondi and Gold, badgering them into discussing the issues that occupied his thoughts. As Gold described it, Hoyle “would continue . . . sometimes being rather repetitious, even aggravating, drumming away at particular points without any obvious purpose.” One of Hoyle's obsessions was Hubble's observation of the universe's rate of expansion.

 

In the years since Hubble and Humason had measured the de Sitter effect, Friedmann and Lemaître's expanding universe had become firmly entrenched in the standard lore of astrophysics. While Lemaître's primeval atom was too esoteric and removed from observations to be completely adopted, it was generally felt that his model for the universe was broadly correct—the universe had been expanding from some initial time, and the details of how it began would be ironed out at a later date. It was, without a doubt, a huge success for astrophysics and the general theory of relativity.

There was, nevertheless, a baffling problem with Friedmann and Lemaître's universe that didn't seem to go away. It had been apparent from the moment Hubble made his groundbreaking measurement. Hubble had found that the expansion rate of the universe was approximately 500 kilometers per second per megaparsec. This meant that a galaxy that was about a megaparsec distant from us (roughly 3 million light-years) would be speeding away from us at 500 kilometers per second. One that was 2 megaparsecs would be speeding away at 1,000 kilometers per second. And so on. Hubble's subsequent measurements seem to confirm this value. From this number, now known as the Hubble constant, it was possible to use Friedmann's and Lemaître's models for the evolution of the universe, wind back the clock, and figure out the exact moment in time when the universe came into being. And by doing this it was possible to work out that the universe was about a billion years old.

A billion years might seem like quite a long time, but in fact it was simply not long enough. In the 1920s, radioactive dating had determined that the Earth was over
2
billion
years old. And work by the astronomer James Jeans seemed to pin the age of clusters of stars at hundreds to thousands of billions of years. The ages of star clusters were later revised down, but there was no doubt about it: it seemed as if the universe was
younger
than the stuff it contained. That simply couldn't be true, but there seemed to be no way around the paradox. Willem de Sitter summed up the situation in 1932 by saying,
“I am afraid all we can do is to accept the paradox and try to accommodate ourselves to it.” The situation hadn't improved by the time Hoyle, Bondi, and Gold became interested in the expanding universe.

When the Cambridge trio started thinking about cosmology, the age paradox seemed like a glaring failure of Friedmann's and Lemaître's models. But what really troubled Hoyle, Bondi, and Gold was something much deeper and much more conceptual. In winding back the clock of Friedmann's or Lemaître's model the beginning of the universe corresponds to a moment when the whole of space is infinitely concentrated at a single point. In other words, space, time, and matter came into being at that one, initial instant. To Hoyle and his friends this was anathema. As Hoyle would put it, “It was an irrational process that cannot be described in scientific terms.” What laws of physics could be used to describe the creation of something out of nothing? It was inconceivable, and for Hoyle it was
“a distinctly unsatisfactory notion, since it puts the basic assumption out of sight where it can never be challenged by a direct appeal to observation.” Their dismissiveness echoed Eddington's appalled assessment of Lemaître's primordial egg.

It was a movie,
Dead of Night,
that led Hoyle and his colleagues to take a fresh look at the universe. Made in 1945,
Dead of Night
is a horror movie with a circular structure, the ending neatly matching the beginning. With no real beginning and end it is a claustrophobic vision of an endless universe. And it intrigued Hoyle, Bondi, and Gold. What if the universe was in fact like that? There would be no initial time, no primordial egg.

Bondi and Gold viewed the problem of the initial time—or as Hoyle would later call it, the “Big Bang”—from an almost abstract, aesthetic point of view. Over the centuries, descriptions of the universe had moved away from having special, preferred positions in space. Friedmann and Lemaître, like Einstein before them, postulated that the universe was completely featureless, with no center or preferred place from which things evolved or were observed. There was true democracy among all points in space. So why not promote this principle, the cosmological principle, to something far more complete and all-encompassing? Why not assume that all points in space
and
moments in time were the same? There would be no beginning, just an eternal universe that would remain in a steady state for all time.

Hoyle set about figuring out the details of such a proposal. In Friedmann and Lemaître's universe, energy would be diluted with the expansion and slowly decrease with time. If the universe was to be truly in a steady state, the energy would have to be replenished somehow to keep the universe chugging along. And so Hoyle decided to fix Einstein's field equations, much as Einstein had tried to do when he was constructing his now-defunct static universe. Hoyle postulated the existence of what he called the creation field, or C-field as it became known, that would create energy over time. Hoyle's steady-state universe would be sustained by this mysterious source of energy, which had never before been seen. In Hoyle's universe one of the sacrosanct laws of physics—conservation of energy—went down the drain. Hoyle argued it wasn't that big a deal, for all that was needed was
“about one atom every century in a volume equal to the Empire State Building.” Almost nothing.

Two papers, one by Hoyle and another by Bondi and Gold, came out in 1948 in the
Monthly Notices
of the RAS. The reception was mixed. One of the fathers of quantum physics, Werner Heisenberg, who had stopped by in Cambridge when Hoyle presented his C-field paper, thought it was the most interesting idea to come out of his visit. E. A. Milne, an Oxford professor of mathematics, rejected it outright, stating, “I do not believe the hypothesis of the continual creation of matter is necessary, nor do I consider that it is on the same footing as the assumption that the universe as a whole was created at a particular epoch.” Max Born, who had supervised Robert Oppenheimer in Göttingen, simply couldn't stomach the changes Hoyle was proposing, “for if there is any law which has withstood all changes and revolutions in physics, it is the law of conservation of energy.” And the great man himself, Albert Einstein, paid little attention to Hoyle's model, claiming it was simply a piece of “romantic speculation.” What seemed to the trio of astronomers like a simple, obvious solution to such a fundamental problem in cosmology was being dismissed as outlandish and unnecessary. Hoyle was frustrated by what he perceived as the unreasonableness of his colleagues. As he put it, he was quite “worn out with explaining points of physics, mathematics, fact and logic to obtuse minds.”

And then, an opportunity to promote his model that would far surpass the impact of any paper or seminar series landed in Hoyle's lap. The BBC was planning a series of radio lectures by the Cambridge historian Herbert Butterfield. Butterfield pulled out at the last minute and the young Fred Hoyle, who had some experience of broadcasting, was invited to take Butterfield's place and record a series of programs on the universe and cosmology, five in total. In them Hoyle could expound on the problems of cosmology, the young universe with old galaxies, and how Friedmann and Lemaître's universe created more problems than it solved. And he could describe the virtues of his steady-state universe. Hoyle could bypass all the conventional methods and present his ideas to the whole country as a fait accompli. Everyone would know about his theory.

Hoyle's BBC lectures were incredibly successful and Hoyle became a well-known figure, one of the first media dons. The public warmed to his description of the universe, and it took hold in the popular imagination. But by taking such a public stage to promote his own model above the much more well-established and accepted expanding universe discovered by Friedmann and Lemaître, Hoyle rankled his colleagues, and the concept of a steady-state universe suffered a backlash as a result. While Hoyle had succeeded in placing the steady-state universe on a public stage, resistance among his colleagues became more firmly entrenched. As Hoyle later recalled,
“I found it difficult to get my papers published during the first two or three years of the 1950s.”

Nevertheless, the steady-state universe took hold as a viable alternative to the expanding universe of Friedmann and Lemaître that had won over Einstein. The great discoveries of the 1920s in cosmology and general relativity were under assault. But in the next few years, a completely new window on the universe would open up and cast all these models in a different light.

 

“I do not think it unreasonable to say that [Martin] Ryle's motivation in developing a program for counting radio sources . . . was to exact revenge,” recalled Hoyle of his former colleague. It was an uncharitable thing to say, but there was definitely an element of truth in it. For Martin Ryle was a volatile, irascible character, competitive and suspicious. Even within Cambridge, Ryle would isolate himself from the rest of the faculty, going to work near the radio telescopes based at what used to be the Lord's Bridge railway station, “in a shed in the fields,” as one of his colleagues recalls. He would have a distinguished career—he would become the Astronomer Royal in 1972 and win the Nobel Prize in 1974—yet throughout, Ryle behaved as if he were constantly under threat, enforcing a bunker mentality in his group.

Martin Ryle had also come out of the radar generation. The son of a Cambridge professor, Ryle graduated from Oxford in 1939 with a first-class degree. Like Bondi, Gold, and Hoyle, Martin Ryle worked on radar during the war, coming up with tricks for jamming the German radar systems and subverting German rocket guidance systems. After the war Ryle went to Cambridge, where he set about applying his skills to developing, and at some point dominating, the new field of radio astronomy. He was not alone, for when Bernard Lovell, who had also spent the war enmeshed in the development of radar, moved to Manchester, he set about building one of the largest steerable radio telescopes in the world at the Jodrell Bank Observatory. In Australia, Joseph Pawsey spent his war years developing radar for the Royal Australian Navy before setting up his own radio astronomy group in Sydney.

The first steps in radio astronomy had been taken a few years before, when Karl Jansky, an engineer working for Bell Telephone Laboratories in New Jersey in the early 1930s, realized that the universe was hissing at him. Jansky had been asked to find the source of the annoying static that was making conversations over the radio and even broadcast radio programs sometimes impossible to hear. Jansky just wanted to fix the radios—he had little interest in the mysteries of outer space.