The Perfect Machine (28 page)

Ellis’s spray process for the sixty-inch mirror transformed the working area inside the steel building at West Lynn into a self-enclosed hell on earth. A bank of transformers along one wall hummed with the eight hundred kilowatts of power needed to heat the twelve-foot-diameter furnace. The steel walls reverberated with a low-frequency hum that made talk impossible. The temperature inside the furnace was over 1900°F, and heat waves caused the air in the building to undulate until the walls and equipment seemed to shimmer. The temperature at the nozzles of the burner was double that of the disk itself, close to 4000°F, so hot that the burner had to be shielded in an enclosure of fused quartz to withstand the temperature. A heavy outer pipe shielded the smaller pipes for quartz powder, hydrogen, oxygen, and cooling water to the burner. Technicians could only view the process through a thick, green glass window set into a steel viewing protector.

In the first trials the new burner apparatus worked exactly as Ellis had planned, laying down fused quartz at a much higher rate than even his optimistic predictions. The intense sleet storm of quartz that fell into the mold surface appeared to fuse readily with the material
laid down behind it, and the disk built up quickly. It wasn’t until the trial disks cooled that Ellis discovered that the layers of quartz had failed to fuse. Instead of a single, fused disk, what emerged was a lamination of partially fused layers, a quartz
millefeuille
pastry.

Ellis’s answer was more tests. Each cycle of heating and cooling the furnace took at least a week and an incredible quantity of fuel, so Ellis went back to the small furnace for testing. The only way he could get the quartz to fuse completely was to slow down the rate of spraying until it was too slow to be practical. More tests finally identified the problem: The new process for pulverizing and filtering the quartz filtered out exactly those fine particles that would have provided the fusion between the layers of sprayed quartz.

Ellis decided to start over again and prepare new batches of quartz instead of reprocessing the quartz that had already been prepared. He would use cheap native quartz for the body of the disk, instead of expensive Brazilian quartz. The native quartz had to be hand selected to avoid white streaks, which seemed to produce bubbles. Ellis assigned three men to the job of sorting an enormous rock pile of quartz into three smaller piles of quartz with no white streaks for the faces of disks, pieces with minimal white streaks for the base material, and a discard pile with excessive white streaks. Seventy-five percent of the quartz fell into the first two categories and was then ground in the ball mill.

Ellis tried the newly prepared quartz in another experimental disk. If the quartz had even minimal white streaks, disks came out looking “more like porcelain than quartz because of the great number of small bubbles.” When he tried to fuse a layer of pure Brazilian quartz onto the bubble-laden base, the heat transferred to the base during the process expanded the bubbles, raising the mass “like yeast raises bread.”

Guessing that the problem might be moisture in the quartz, Ellis tried drying samples for periods from one hour to one week, at a temperature of 450°C. The drying made no difference. No matter what he tried, he could not produce a satisfactory disk. He kept turning back to an earlier experimental disk, number thirteen, made by the older procedure, from the identical quartz, from the same quarry, even from the same part of the quarry as the material they were currently using. That blank had come out essentially bubble-free. When he tried a sample of quartz left over from the earlier disk, it fused beautifully. It was as if he had left out a magic ingredient that had made the earlier tests work.

Hands-on experimentation was the specialty of the West Lynn laboratory, the core of Thomson’s reputation. Ellis had notes from the various stages of their experiments, but his methodology was trial and error, adding more or less of one ingredient or another, or substituting one grade of quartz for another. No one at GE fully understood the processes at work inside the furnaces. When Ellis offered a description
of the problems, it wasn’t the sort of rigorous explanation scientists like Anderson or Hale would expect:

The pulverized quartz does not become melted while passing through the flame from the burner to the work, but is caught in the sticky surface of the work and melted there. Some of the quartz is vaporized from the surface and perhaps from some of the extremely fine material passing through the burner. This vapor condenses on the cooler parts of the surface and furnace forming a white spongy layer of varying thickness. To this deposit is added some of the larger particles of pulverized quartz by the action of the flame, or by pieces bounding from surfaces that have not yet reached the sticky state. The surface layer thus formed seems to be a very good heat insulator, and which must be melted by heat transferred through the layer of quartz being laid down by the burner as it passes over the surface.

Ellis concluded that even a trace of “white material” in the quartz would contribute excessive bubbles or contaminants of iron or chromium to the laid-down quartz layers. The bubble-filled material then became so effective as an insulator that it did not pass the heat to the layers beneath, preventing complete fusion of the layers.

Desperate to get the process working again, Ellis tried alternate materials, like flint shot, a pure silica sand from an enormous deposit in Ottawa, Illinois. He had used the sand successfully when he molded the bases of the earlier disks, but when he tried pulverizing a new batch for the sprayer, the quality and purity varied so much that a process to prepare production quantities would require “more development.” He finally went back to the quartz pile in the yard outside the laboratory. For the next batch Ellis had a single man grade the quartz in an effort to assure uniformity of the grading standard. The man would study each piece of quartz against a black background, holding the samples underwater to minimize reflections that might hide the white streaks. A quick test of the new quartz appeared to fuse, and Ellis hoped that by December 1930 he would have enough quartz on hand to begin the long-awaited sixty-inch mirror blank.

At least, Ellis assured Hale and Anderson, the current problems were the last they would encounter. “Every man on the work is doing everything he can to produce a 60-inch mirror at the earliest possible date, for with this experience behind us the rest will be easy. There will, of course, be problems to be solved in making the 200-inch mirror, but it does seem to us that practically everything that can happen has already happened, and we have every hope that the coming year will be brighter.”

He finally started spraying a sixty-inch mirror for the telescope on December 8, 1930. Miraculously, everything worked. On January 6, 1931, Ellis triumphantly telegraphed Hale: “We have laid one more ghost. The first sixty inch mirror blank has been reduced from annealing
temperature approximately 1100 degrees C. to room temperature in eight days, an astoundingly short time compared with glass.” Finally, it seemed, Ellis had licked the fused-quartz demons. Hammond in the GE publicity department prepared another article for the journal
The Glass Industry,
celebrating the achievement. A GE executive named McManus, at the main office in Schenectady, began negotiating with representatives of other observatories, including Harlow Shapley at Harvard, for future orders.

In Pasadena, Hale and his colleagues were delirious with excitement. Walter Adams and Theodore Dunham of the Mount Wilson staff traveled to West Lynn to see the sixty-inch when it came out of the annealing oven. They liked what they saw. Even Hale was encouraged. “If it were not for the ‘fierce’ cost,” he wrote, “I should feel much encouraged. Their capacity for spending is appalling…. although they are two years behind their original time schedule some of us may live long enough to see a 200-inch disk, if the money holds out.”

14
Change of Guard

Caltech was a tiny school with a big reputation. Only a decade after its founding, the superb faculty Hale, Noyes, and Millikan had recruited had brought the institution to the front ranks of the hard sciences. There were still only few dozen regular faculty members, but the list of speakers who trekked to the red-tile roofed stucco buildings under the visiting scholars program included Albert Michelson, Michael Pupin, and the cream of European physics: Niels Bohr, Max Born, Paul Dirac, Erwin Schrodinger, and Werner Heisenberg. Caltech had come a long way from its shaky beginnings as a polytechnic school.

In the spring of 1931 Einstein joined the faculty as a visiting professor. Einstein was a celebrity, his name celebrated in Cole Porter songs,

Your charm is not that of Circe with her swine
Your brain would never deflate the great Einstein.

and his theory in e. e. cummings’s poems,

… lenses extend
unwish through curving where when till unwish
returns on its unself.

In Southern California, Will Rogers wrote, Einstein “ate with everybody, talked with everybody, posed for everybody that had any film left, attended every luncheon, every dinner, every movie opening, every marriage and two-thirds of the divorces. In fact, he made himself such a good fellow that nobody had the nerve to ask him what his theory was.”

Except at Caltech. Richard Tolman, professor of physical chemistry and mathematical physics and dean of the graduate school, had been at Caltech for almost a decade, working on relativity, statistical mechanics, and cosmology. Ever since Hubble had discovered red shifts in the light from distant galaxies and had begun to calculate the
speed of recession of those galaxies, Tolman had worked to integrate Hubble’s findings into a workable cosmology of curved space. Hubble wasn’t much of a relativity scholar, but he loved the publicity, especially the photographs, always in a tweed jacket with his trademark pipe. When Einstein went to Mount Wilson and posed for photographs at the one-hundred-inch telescope, Hubble gave his usual explanations about how the giant telescope was used to determine the structure of the universe. “Well, well,” Mrs. Einstein said, “My husband does that on the back of an old envelope.”

The one-hundred-inch telescope was working hard. Hubble and Humason had a near monopoly of dark time on the telescope to carry on their search for distant galaxies. They used every trick to reach farther and farther out with the one-hundred-inch telescope, including new emulsions for the spectrograms, and new auxiliary lenses. Hubble soon had images from enough nebulae to derive a classification scheme for galaxies, his famed tuning fork with elliptical galaxies on the handle and the spiral and barred-spiral types classified by their position along the two tines. The derivation of a morphology of distant galaxies, less than a decade after the very existence of “island universes” had been demonstrated, elevated cosmology into a hard science.

With each improvement in technique, Hubble and Humason measured bigger red shifts, which translated into larger velocities of recession and more distant objects. In February 1931, using a new Payton spectrograph objective, which had been developed as part of the two-hundred-inch project, they succeeded in recording the spectrum of a minute spiral nebula of the seventeenth magnitude, “far beyond the reach of all other instruments.” To record the spectrum Humason had to keep the faint object centered on the slit of the spectrogram for seventeen hours, over three nights. “The nebulae are becoming so faint,” he wrote, “that they are difficult to see.” From the measured red shift, Hubble calculated that the galaxy was receding at close to twenty thousand kilometers per second. “Either the entire universe is flying apart,” Hale wrote when he heard the report, “or a new and fundamental physical law must be elucidated to account for these extrordinary phenomena.”

The consequences of Hubble’s work were as exciting for cosmology as for observational astronomy. The universe was no longer the stable constant it had always seemed. Hubble and Humason had discovered thousands of “island universes,” of infinite variety, streaming away from one another at inconceivable velocities. What could account for this seeming entropy? Tolman set to work on the problem and gradually concluded that the match between Hubble’s data and Einstein’s theory of gravity
without
the cosmological constant was too compelling to ignore.

For Tolman, Einstein’s visit to the campus was a grand opportunity.

Tolman, a witty man with a deadpan delivery, also served as campus toastmaster, a duty that reached fever pitch when Einstein arrived in Pasadena. In the evenings he would introduce Einstein at various functions. During the days Einstein attended colloquiums and private meetings with faculty and graduate students, including enough sessions with Tolman that he was finally persuaded that the cosmology of an expanding universe was probably correct. Einstein had actually wavered on the cosmological constant in a paper. When Sir Arthur Eddington chided Einstein about dropping the constant, Einstein said, “I did not think the paper very important myself, but de Sitter [Willem de Sitter, coauthor of the paper] was keen on it.” De Sitter also didn’t want the rap. “You will have seen the paper by Einstein and myself,” he wrote to Eddington. “I do not myself consider the result of much importance, but Einstein seemed to think that it was.”

Five months after he left Caltech, Einstein wrote Millikan from Berlin to report that “further thought regarding Hubbel’s
[sic]
observations have proved that the phenomena adapts itself very well to the theory of relativity.” The big telescopes in Southern California had already reached far enough to correct Einstein’s original theory.
^*

Hale had envisioned a broad program of cooperation between the faculties at Caltech and the staff of the Mount Wilson Observatory. With Hubble, Walter Baade, who had originally come on a visiting fellowship from Hamburg, van Maanen, and a constant influx of bright younger fellows, Mount Wilson was the preeminent group of observational astronomers. Their offices on Santa Barbara Street were a short drive or a long walk from the Caltech campus. Despite the proximity, and Hale’s hopes, the only open cooperation was the Astronomy and Physics Club, a joint effort of the Bridge Laboratory and the Mount Wilson Observatory, which met in a weekly colloquium for featured speakers.