The Day We Found the Universe (42 page)

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 spacetime 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 spacetime 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
Nature
with 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 superatom, 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.