The Day We Found the Universe - Marcia Bartusiak (2009)

Discovery

Chapter 16. Started Off with a Bang

On November 30, 1930, Einstein, his wife, Elsa, his secretary, and a scientific assistant left Berlin for Antwerp, where they embarked on the steamer Belgenland. It was Einstein's second visit to the United States but his first journey to America's West Coast. Before leaving, Frau Einstein made a last-minute shopping trip to purchase a raincoat for the father of relativity. “Would it not be more practical to have the herr professor come here so we can give him an exact fit?” said the clothing store salesman. “If you knew how hard it was even to persuade my husband he needed a new coat, you wouldn't expect me to fetch him here. I wish you had my worries,” she replied. It was teasingly said that Einstein was going to Pasadena to hunt for the sole twelve men in the world who could understand him.

The revered physicist arrived in New York on December 11, where he and Elsa were greeted by a barrage of journalists, photographers, and newsreel men, a chaotic scene that greatly discomfited Einstein. “This reminds me of a Punch and Judy show, all of you standing there watching us so intently,” he remarked in German. The press described him that day as small, bright-eyed, his almost white hair trained back in a bushy pompadour, and “his face … as smooth as a girl's except for the tiny wrinkles about his eyes.” Out on the deck, a cold damp wind soon blew through his locks, swiftly turning the carefully groomed pompadour into his well-known disheveled hairstyle. After a four-day stay in New York, he and his party continued their voyage on the Belgenland for California, by way of the Panama Canal.

Arthur Fleming, a member of the California Institute of Technology's executive council, first extended the invitation to visit, extolling his town's summery climate and rich scientific atmosphere. Einstein, then looking for a good rest among men who spoke the language of mathematics, eagerly accepted. For one, it was an opportunity for him to meet Albert A. Michelson, the physicist whose inexplicable failure to measure a predicted change in the speed of light due to Earth's motion through an “ether” permeating space was at last explained by Einstein's special theory of relativity, which did away with the ether altogether.

Aware of Einstein's dislike for publicity, his California hosts tried to dispense with an official welcome, as in New York, but to no avail. Upon docking in San Diego on New Year's Eve, the German visitors had to endure four hours of speeches, presentations, tours, and a radio talk. Only after all the hoopla had ceased were Einstein and Elsa finally taken northward by car, eventually settling into a small Pasadena bungalow specially renovated and furnished for their stay. While shunning many public events over their two-month visit, the Einsteins enjoyed a steady round of private engagements. Over the ensuing weeks, they hosted a dinner for the director of the Los Angeles Philharmonic (with Einstein briefly playing the violin for his guest), visited a Hollywood studio, had dinner at the home of film comedian Charlie Chaplin, and motored out to Palm Springs for a four-day holiday. They did put up with the glare of the celebrity spotlight on one special occasion. The couple, he decked out in tuxedo and she in full-length evening gown, attended the premiere of Chaplin's latest movie, City Lights, where Einstein laughed like a little boy. There was a simple reason for this exceptional night on the town: Chaplin, instantly recognizable throughout the world, was Elsa's matinee idol. “They cheer me because they all understand me, and they cheer you because no one understands you,” Chaplin told Einstein as they walked into the theater to shouts and clapping that night.

Einstein's days, though, were solely devoted to research, with visits to either Caltech or Mount Wilson's Pasadena headquarters for talks and consultations with fellow scientists. For his convenience, he had a small army of chauffeurs at his beck and call, including Grace Hubble. When driving Einstein to an engagement one day, he turned to her and said, “Your husband's work is beautiful—and he has a beautiful spirit.” Einstein had been given a room at Mount Wilson's main offices right across from Hubble's. The observatory made every attempt to shelter him from the press and allow him maximum time to interact with his colleagues, even keeping the doors locked at the headquarters and issuing keys. Hale, though, stayed away from all the partying. “I have kept completely out of the Einstein excitement,” he told a friend, “and have not seen him at all until he dropped into my lab the other day, fortunately with no reporter. He is very simple and agreeable and greatly dislikes all the newspaper notoriety. But as the town is swarming with reporters, several of them sent out here for the occasion by eastern papers, he cannot escape entirely.”

Einstein and his wife, Elsa, with Charlie Chaplin at the premiere
of Chaplin's film City Lights, January 1931 (Copyright Jewish
Chronicle Ltd/HIP/The Image Works)

That was certainly the case on January 29, 1931, when a carefully orchestrated expedition was arranged for Einstein. That morning the world's premier physicist and Hubble, its foremost astronomer, settled into the plush leather seats of a sleek Pierce-Arrow touring car and traveled, along with a number of other observatory staffers, up to the site of Hubble's astronomical triumphs—the sprawling telescope complex atop Mount Wilson. Despite warnings from his doctor to avoid high elevations, Einstein was eager to make the trek, so he could view up close the machinery that had had such a direct bearing on his theoretical investigations.

This event was considered so noteworthy that a young filmmaker named Frank Capra, still three years away from his first Academy Award for the screwball comedy It Happened One Night, came along to document Einstein's every move on the mountain that day. Clambering with a few others into an open steel box, operated by cables, Einstein was first carried to the top of the 150-foot-high tower telescope, used exclusively for the study of the Sun. After admiring the view of southern California and duly photographed in the cold, stiff breeze, he again went aboard the miniature elevator back to the ground. “And here he comes,” said the announcer in the newsreel's opening, “down from the sun tower, after a hard morning, looking a few million miles into his favorite space.”

After lunch came the opportunity to visit the 100-inch telescope, where Einstein again dutifully posed for Capra, peering through the eyepiece while Walter Adams stiffly spoke, directly to the camera. “This hundred-inch reflector was completed about thirteen years ago and has contributed in three or four notable ways to progress in astronomy,” he droned. All the while Hubble was also in the frame, wearing his sporting plus-fours (golf trousers cut four inches below the knee) and silently puffing away on his ever-present pipe. Away from the camera, Einstein delighted in the telescope's instruments. This was his first view of a large reflecting telescope, and he was quick to grasp the intricacies in its construction and operation. Like a child at play, the fifty-one-year-old physicist scrambled about the framework, to the consternation of his hosts. Nearby was Einstein's wife. Told that the giant reflector was used to determine the universe's shape, Elsa reportedly replied with wifely pride, “Well, my husband does that on the back of an old envelope.”

For the cameras Einstein pretends to peer through the 100-inch
telescope during his visit to Mount Wilson. Edwin Hubble (center)
smokes his pipe and observatory director Walter Adams (right) looks on.
(Courtesy of the Archives, California Institute of Technology)

After an early dinner the party returned to the 100-inch telescope, when Einstein was at last able to do some real observing, peering at Jupiter, Mars, the asteroid Eros, several spiral nebulae, and the faint companion of the star Sirius. He remained in the dome until after one o'clock, finally retiring under protest and with the stipulation that he be called in time to see the sunrise. Everyone returned to Pasadena at about ten o'clock that same morning.

Five days later, astronomers and theorists gathered in the spacious library of the observatory's Pasadena offices, books lining the walls from floor to ceiling, to hear Einstein's assessment of what he had learned and absorbed from his visit to the mountain. Up to this point, he had been very wary of considering a universe in restless motion, curtly dismissing the models fashioned by both Friedmann and Lemaître. Einstein, by far, preferred a universe that stayed put. But on that day he at last conceded that the secret of the cosmos had undoubtedly been revealed by Hubble's observations. Einstein at last let go of his spherical universe. “A gasp of astonishment swept through the library,” according to an Associated Press reporter in attendance. At a follow-up session a week later, Einstein went further and announced that “the red shift of distant nebulae has smashed my old construction like a hammer blow,” swiftly swinging down his hand to illustrate the point to his audience. Einstein at this stage recognized that he no longer needed his cosmological constant to describe this dynamic universe. His original equations could handle the cosmic expansion just fine, which pleased him immensely. From the start, he had had qualms about the ad hoc addition, believing the constant tarnished the formal beauty of his theory. Tacking on the extra term, he reportedly said, was the “biggest blunder” he ever made in his life. The cocky kid was getting older. If he had trusted his equations from the start, he could have predicted that space-time was in motion years before Hubble and Humason confirmed it, which would have rocketed Einstein's reputation, towering as it was, into the stratosphere.

Einstein with Hubble (second from the left) and others from Caltech
and the observatory outside the dome of the 100-inch telescope during
his visit to Mount Wilson on January 29, 1931 (Courtesy of the
Archives, California Institute of Technology)

Given his role in this turnabout, Hubble was soon revered as the man who “made Einstein change his mind.” Aside from perhaps receiving a Nobel Prize, there was no higher accolade in science at the time.

A few weeks before Einstein roamed over the summit of Mount Wilson, Eddington delivered an address to the British Mathematical Association, where he called attention to the notorious elephant in the room, present ever since Lemaître first introduced the concept of an expanding universe. In his masterly 1927 journal article, Lemaître had coyly asked the question that likely arose in the mind of anyone reading the paper: How did this expansion get started? “It remains to find the cause,” he answered at the time.

Eddington in his January 5 talk to the British mathematicians faced this conundrum head-on. In his mind's eye, he mentally put the expansion of space-time into reverse and pondered the condition of the universe at earlier and earlier epochs, back to the very launch of space, time, and all of creation. Could you reach a “beginning of time,” he asked, when all matter and energy had the highest degree of organization possible? Eddington was horrified by this thought. The Cambridge theorist concluded that “philosophically, the notion of a beginning of the present order of Nature is repugnant to me…. By sweeping it far enough away from the sphere of our current physical problems, we fancy we have got rid of it. It is only when some of us are so misguided as to try to get back billions of years into the past that we find the sweepings all piled up like a high wall and forming a boundary—a beginning of time—which we cannot climb over.” A few years earlier, before the reason for the retreating galaxies was even known and he was simply contemplating an early universe with more energy and order, Eddington had already declared that he did “not believe that the present order of things started off with a bang” (a precursor to British astronomer Fred Hoyle using a similar description on a 1949 BBC radio program, this time with an added adjective, which secured the scientific name—Big Bang—for the moment of creation). Eddington, though, preferred a commencement less abrupt and more restrained. “I picture…an even distribution of protons and electrons, extremely diffuse and filling all (spherical) space, remaining nearly balanced for an exceedingly long time until its inherent instability prevails… There is no hurry for anything to begin to happen. But at last small irregular tendencies accumulate, and evolution gets under way…. As the matter drew closer together in the condensations, the various evolutionary processes followed—evolution of stars, evolution of the more complex elements, evolution of planets and life.” The universe, in effect, eased into its expansion, like a massive train starting up slowly and then gaining speed.

Lemaître, however, was far bolder and had no hesitation at all in contemplating a more dramatic genesis. In response to Eddington's repulsion at an abrupt cosmic beginning, Lemaître submitted a short note to the journal Naturewith the splendiferous title: “The Beginning of the World from the Point of View of Quantum Theory.” “If we go back in the course of time,” replied Lemaître, “… we find all the energy of the universe packed in a few or even in a unique quantum…. If this suggestion is correct, the beginning of the world happened a little before the beginning of space and time. I think that such a beginning of the world is far enough from the present order of Nature to be not at all repugnant… We could conceive the beginning of the universe in the form of a unique atom, the atomic weight of which is the total mass of the universe. This highly unstable atom would divide in smaller and smaller atoms by a kind of super-radioactive process.” He called his initial compact cauldron the “primeval atom.” Today's stars and galaxies, he surmised, were constructed from the fragments blasted outward from this original superatom.

Lemaître was spurred by the revelations of atomic physics in the early decades of the twentieth century, where radioactive elements were seen to endure over times similar to the age then calculated for the universe, a few billion years. “The evolution of the world can be compared to a display of fireworks that has just ended: some few red wisps, ashes, and smoke,” the Belgian cleric would later write. “Standing on a well-chilled cinder, we see the slow fading of the suns, and try to recall the vanished brilliance of the origin of the worlds.” This idea would later be revised by others to show how our universe evolved, not from a super-atom, but from a cosmic seed of pure energy. From Lemaître's poetic scenario arose today's vision of the Big Bang, the cosmological model that shapes and directs the thoughts of cosmologists today as strongly as Ptolemy's crystalline spheres influenced natural philosophers in the Middle Ages.

Though ordained as an abbé, later rising to the rank of monsignor, Lemaître did not endure the fate of Galileo in contemplating a scientific explanation for heaven's workings, in this case the universe's creation. As Helge Kragh has noted, “Lemaître believed that God would hide nothing from the human mind, not even the physical nature of the very early universe.” Times had assuredly changed—while Galileo was condemned by church officials to house arrest for his defense of a Sun-centered universe, Lemaître was lauded by the Church for his cosmological breakthrough. However, nothing could upset Lemaître more than assuming his cosmological model had been inspired by the biblical story of Genesis. His contemplation of the origin of space and time, he persistently asserted, arrived exclusively from the equations before him. As a scientist/priest, Lemaître religiously kept his physics and theology in separate, unattached compartments.

But the Big Bang model faced a number of challenges before it could be fully accepted. The biggest hurdle was the estimate of the universe's age, based on early (and incorrect) measurements of the rate of cosmic expansion. Hubble's initial rate, calculated from a relatively small sample of galaxies, suggested that the universe originated just two billion years ago, but astronomers already knew of stars around ten billion years old. Looking closer to home, it was also less than the estimated age of Earth. Geologic evidence at the time indicated that Earth's crust was at least three billion years old, likely more. This paradox posed a dilemma for the model for quite a while. How could Earth possibly be older than the universe?

There were other loose ends. For one, the Milky Way still appeared to be far larger than the other galaxies. The Andromeda galaxy, the closest spiral to us, shared so many features with the Milky Way—the same disk of stars, the same system of globular clusters arranged in a halo around it, the same variable stars blinking on and off—and yet all these objects appeared fainter than those in the Milky Way, based on Hubble's initial distance measurement. More than that, Andromeda was smaller. This greatly bothered astronomers, who were now readily applying the Copernican rule to the entire universe: It is unlikely that we occupy a privileged place in the cosmos.

This puzzle persisted until 1952, just when Hubble's long reign as the emperor of cosmology was coming to an end. Having gone into military work during World War II, Hubble had a lot of catching up to do at the war's end, but ill health prevented him from getting back on top. By then Walter Baade, a gifted observer, was beginning to overshadow Hubble with his revelatory work that at last put the universe (and the Big Bang) in better shape. Using both the 100-inch telescope during the war and later the 200-inch launched in 1948 on Palomar Mountain in California, Baade was able to prove that there were two distinct kinds of Cepheid stars. The Cepheids that Hubble used to determine the distance to Andromeda and other galaxies were actually more luminous than the Cepheids that Shapley used to determine his distances to the globular clusters surrounding the Milky Way. Consequently, Hubble had been underestimating his distances to Andromeda and the other galaxies. Hubble's distances had to be completely reworked. Andromeda, for example, was actually twice as far out, which also meant it was bigger than anyone had perceived and so made it more like the Milky Way's twin. Andromeda wasn't smaller or fainter at all, just more distant than previously thought—and that meant the Milky Way was no longer the special kid on the block. Those who desired nature to be uniform breathed a huge sigh of relief. This adjustment had to be made to all the galaxies then measured, essentially doubling the size and age of the universe. This modification at last took the Big Bang model out from under its cloud. With Hubble's rate of expansion determined more accurately as well, as more and more galaxies were measured, the estimated age of the universe was further increased, which at last allowed enough time for all the stars and planets to form after an explosive birth of space and time.

“Never in all the history of science,” said Willem de Sitter in 1931 at a Boston lecture, “has there been a period when new theories and hypotheses arose, flourished, and were abandoned in so quick succession as in the last fifteen or twenty years.” And perhaps never again will astronomy face such a dramatic shift in its conception of the universe. It took only three short decades—from 1900 to 1930, virtual seconds into our past when weighed against humanity's life span—to make this mind-altering transition. The Milky Way, once the universe's lone inhabitant floating in an ocean of darkness, was suddenly joined by billions of other star-filled islands, arranged outward as far as telescopes could peer. Earth turned out to be less than a speck, the cosmic equivalent of a subatomic particle hovering within an immensity still difficult to grasp. It didn't stop there. Astronomers barely had time to adjust to this astounding celestial vastness when they were faced with the knowledge that space-time, the universe's very fabric, was expanding in all directions, carrying the galaxies with it. It was a rapid one-two punch from which astronomy is still reeling, as observers and theorists alike try to make sense of all its details: how the Big Bang was ignited, how the myriad galaxies were born and evolve, how (and if) the expansion will end.

James Keeler could not possibly have imagined where his pioneering explorations were going to lead when in 1898 he first walked over to the Crossley reflector, a pip-squeak of a telescope compared to Lick Observatory's grand refractor, and made the simple decision to focus his research on the spiral nebulae. But his observations from Ptolemy Ridge had broad repercussions. He at last made the professional astronomical community sit up and take notice of celestial objects other than planets and stars. Reigniting up the cause after Keeler's death, Heber Curtis generated even more momentum. The arsenal of data he gathered throughout the 1910s with the Crossley supported a very strong case that the spirals were no less than separate galaxies. Though it was all circumstantial evidence, Curtis's observations laid down a substantial foundation that made it far easier for Hubble to place the final capstone, his distance measurements to the closest spirals, that at last persuaded his fellow astronomers. Both Keeler and Curtis were vital pathfinders, carving out a route that led to Hubble's ultimate triumph.

In a similar fashion, Vesto Slipher spent many lonely hours at his Lowell Observatory telescope, year after year, building up the reservoir of galaxy velocities that Hubble then used to establish his historic link between a galaxy's redshift and its distance, a systematic pattern that served as powerful proof for the expanding universe predicted by Georges Lemaître. Yet Hubble remained remarkably silent about the meaning of what he and Humason had found. Neither in his personal conversations nor in his writings did Hubble discuss the implications of his finding on ideas concerning either the evolution of the universe from a primitive state or the necessity of a creation event. That would come from others. Hubble was not comfortable with imaginative speculation, beyond what his observations could plainly demonstrate. Hubble was always the skeptical scientist, forever the questioning lawyer.

Nevertheless this image of Hubble, someone aloof and hesitant to embrace a dynamic universe, slowly faded and was replaced by another portrait entirely. Over time, the story of the expanding universe's discovery evolved. Particularly after Hubble's death, more and more references were made to him as the sole discoverer of the universe's expansion. Poor Humason was shoved off to the shadowy sidelines of popular history, Slipher largely forgotten, and Lemaître's crucial theoretical interpretation diminished. Fine distinctions and the sharing of credit got lost. A rousing narrative is now usually drawn with Hubble as the main protagonist, even though in reality he was not the expanding universe's champion at all. But, as historians Kragh and Smith put it, “a growing community of American astronomers… by the 1960s were concentrating to an unprecedented degree on the study of galaxies [and] fashioned a hero, a founding father and a figure around whom they could drape a single version of the history of the discovery of the expanding universe.” The public seems to yearn for heroes, and thus Hubble—so handsome, so manly, so erudite—easily joined the scientific pantheon, along with Newton and his apple, Galileo and his telescope, Darwin and his finches.

It is the victorious leader who is now best remembered in the public's mind, not his accomplished predecessors or productive partner. Humason became Sancho Panza to Hubble's Don Quixote. Only this time, the twirling windmills are replaced with spiraling nebulae, and the celestial man of la Mancha ends up conquering them all with dazzling success.