Professor George Smoot

is an astrophysicist and a cosmologist.
Address: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720

From April 1994 CURRENT BIOGRAPHY (Vol 55, No 4)

"We had observed the oldest and largest structures ever seen in the early universe," the cosmologist George Smoot explained on April 23, 1992, after announcing that his team of scientists had discovered wrinkles in the fabric that made up the early universe. "These were the primordial seeds of modern-day structures such as galaxies, clusters of galaxies, and so on. Not only that, but they represented huge ripples in the fabric of space-time left from the creation period." As team leader for the group that designed and studied information from one of the three instruments on the Cosmic Background Explorer satellite, Smoot is responsible for the best picture of the early universe available to science. Using instruments carried by balloon, on U-2 spy planes, and finally by satellite, Smoot has spent the last twenty years examining the faint but ever present microwave radiation remnants from the time when light first became visible in the universe, 300,000 years after the big bang and 15 billion years ago. Destroying the conception of the universe then held by most astronomers, in 1977 Smoot discovered that our galaxy is not only involved in the general expansion as is everything in the universe, but it is also travelling over a million miles per hour relative to the universe's expansion, demonstrating that matter was distributed unevenly throughout the universe, instead of uniformly as was thought. Smoot shook the scientific community again with his 1992 announcement of ripples in space. Called "the discovery of the century, if not of all time," by Stephen Hawking, Smoot's uncovering of ripples in space dating from the early universe has for the first time given theorists hard data to use in determining the mechanism of creation of the universe.

George Fitzgerald Smoot III, the older of two children, was born on February 20, 1945 in Yukon, Florida, but due to his father's work as a hydrologist for the United States Geological Survey, his family moved often while he was growing up. His father and mother, a science teacher and later a principal, instilled in George a respect for learning and an interest in science and math, which was abetted by reading science fiction, engineering, and science books by Arthur C. Clarke. George played football and ran track in junior high school, but by the time he reached high school, his interests had swayed toward academics.

After entering the Massachusetts Institute of Technology (MIT) he leaned to premed studies, Smoot soon changed his major to mathematics and physics. Interested in particle physics, he studied the subatomic remnants of collisions of deuterium nuclei for his senior thesis, on his way to earning B.S. degrees in mathematics and in physics, in 1966. Smoot continued to study the decay of subatomic particles for his doctoral thesis and received his Ph.D. in physics from MIT in 1970. At that time particle physics was becoming a crowded field, and Smoot, wanting more impact, jumped to the less crowded discipline of cosmology while a research physicist at MIT in 1970. The switch to cosmology was a natural transition, because subatomic particles were instrumental in the birth of the universe from a single point of energy smaller than a proton. "The science satisfied my need to be searching for something fundamental in nature," Smoot wrote in Wrinkles in Time. "Particle physics and cosmology are about as fundamental as you can get, in their scrutiny of the nature of the universe and its origin."

Smoot left MIT in 1970 to go to the University of California at Berkeley, where he worked with the 1968 Nobel Prize winner in physics, Luis W. Alvarez, on the NASA-funded High-Altitude Particle Physics Experiment (HAPPE, pronounced happy) at Lawrence Berkeley Laboratory. The goal of HAPPE was to design an experiment to find evidence of the big bang, which had become the favored explanation for the formation of the universe among scientists. The big bang theory was first proposed in the late 1920s by the Belgian priest and astronomer Georges-Henri Lema^itre, after Edwin Hubble discovered that distant galaxies were rapidly receding from us, hence the universe was expanding. The theory was scornfully called the big bang by its many critics, but the concept gained wide acceptance after 1964 when Arno Penzias and Robert Wilson of Bell Telephone Laboratories accidently discovered cosmic background radiation, microwave remnants from approximately 300,000 years after the creation of universe, the existence of which had been predicted by big bang theorists.

According to the basic big bang theory (there are many variations of it), 15 billion years ago the observable universe was formed through the explosion of an infinitely small but infinitely dense point in which energy and matter were one, and it has expanded at a steady rate ever since. After the explosion subatomic particles began to separate from energy and eventually formed protons, neutrons, and electrons, but for the first 300,000 years the temperature was too hot for the electrons to attach to the protons and neutrons and form atoms. The radiation that filled the universe, could not travel freely without being absorbed by the free electrons, therefore no light could escape and the universe was opaque. After 300,000 years of darkness, the universe cooled enough for electrons to affix to nuclei, freeing radiation to escape (a process known as decoupling) and allowing light to become visible. The radiation that filled the universe during the period of decoupling still fills the universe in the form of cosmic background radiation, but it has cooled from 3000o Kelvin to less than 3o Kelvin (Kelvin is a scale of temperature in which 0o, -273.15o Celsius, is the temperature that molecules stop moving). Following decoupling the atoms joined to form molecules, which joined to eventually form the universe known today.

Beginning in 1971, Smoot served as HAPPE team field leader in such remote areas as Palestine, Texas and Aberdeen, South Dakota on several balloon launches designed to study the sky from a high altitude, away from misleading signals on the ground. Searching for antimatter, which some theories of creation claimed should be abundant, on the first balloon experiments, the HAPPE team found no evidence of it, hence destroying those theories. One of the HAPPE flights was recognized in 1973 by the American Institute of Physics as one of the world's twelve outstanding physics experiments of the year. After reading James (P. J. E.) Peebles's 1971 book Physical Cosmology, Smoot turned his attention to the study of cosmic background radiation, which could indicate whether the universe was rotating, as some had theorized, or simply expanding without rotation. "I chose to work on measuring cosmic background radiation partly because I knew this: Whatever we learned would be fundamental," Smoot wrote in Wrinkles in Time. "Regardless of what we found, our observations would tell us about the early universe."

With the backing of Luis Alvarez and the help of NASA, Smoot used a differential microwave radiometer (DMR) mounted in a high- flying U-2 spy plane to study the cosmic background radiation in 1976. The DMR, which measured differences in temperature as small as one-thousandth of a degree in the microwave radiation between two points, consisted of two rotating measuring horns at sixty degree angles pointed through the upper hatch of the plane. Surprising Smoot, the data showed that the universe is not rotating and that it is apparently expanding with uniform speed in all directions. Those findings were important, but the most startling discovery was that a dipole effect (a dipole effect is the appearance that radiation is warmer in the direction that we are moving, thereby enabling scientists to determine the direction and speed of movement) appeared in the opposite direction of our galaxy's rotation. That dipole indicated that the Milky Way is moving at over a million miles per hour relative to the rest of the universe, meaning that an object of an enormous size, such as a supercluster of galaxies, must be exerting gravity on and pulling our galaxy.

The finding, announced in 1977, was received warily by astronomers, most of whom believed that objects were spread evenly throughout the universe, but Smoot won over skeptics by repeating the experiments in the Southern Hemisphere, thereby eliminating the possibility that they were misled by some effect caused by their location. Because in a homogeneous universe no objects large enough to produce that much gravity could have formed, the data showed that some regions of the universe are virtually devoid of galaxies while others are filled with billions of galaxies forming superclusters. That revelation demanded a reassessment of the origin of the universe. It had been believed that, at the era of decoupling, matter was evenly distributed throughout the universe, hence the cosmic background radiation that is a picture of that time should have a uniform temperature, as tests had indicated, but with the new knowledge of the uneven distribution of matter, scientists came to believe that for the universe to develop as it has there must have been some areas denser than others at decoupling, with the consequence that there should be variations in the temperature of the cosmic background radiation visible today.

In addition to the balloon and U-2 experiments, since 1974 Smoot had been working a proposal to NASA for a satellite to measure and map cosmic background radiation. Out of the 120 proposals submitted to NASA, the Smoot group and two others interested in cosmic background radiation were selected and told by NASA to join forces. The result was the Cosmic Background Explorer, or COBE (pronounced COH-bee), which carried three instruments to examine the beginnings of the universe: three DMRs like on the U-2 but more sensitive, to map the cosmic background radiation; a far infrared absolute spectrophotometer (FIRAS), to measure the spectral curve of cosmic background radiation, which would tell if it was truly from the big bang; and the diffuse infrared background experiment (DIRBE), to look for cosmic infrared background, the glow from the earliest galaxies. It took the three teams six years to convince NASA that they knew what they wanted to do and how to do it. During that time Smoot, who headed the DMR team, began commuting between Berkeley, where he was working on the balloon and U-2 experiments, and NASA's Goddard Space Flight Center, in Greenbelt, Maryland, where COBE was based.

NASA finally accepted the proposal and scheduled it for a late 1988 launch on the space shuttle, instead of on a rocket as proposed, but after the January 28, 1986 Challenger shuttle accident, twelve years of work were jeopardized when the COBE team was told that they would not have a place on future shuttles. Two other rocket mishaps in 1986 caused an indefinite postponement of all launches, leading the team to consider using a French rocket. Confronted by the possible embarrassment of having a major American science project launched on a French rocket, NASA gave the go ahead to launch COBE in 1989 on a small Delta rocket, which required the size and weight of COBE to be greatly reduced. Having less than three years to redesign the satellite forced a hectic schedule as scientists from the three teams worked closely with engineers to perfect COBE. According to the Goddard Engineering Newsletter, "the transformation of COBE from [the space shuttle] to a Delta launch is probably one of the greatest engineering challenges ever undertaken by the [Goddard Space Flight Center]."

During the development of COBE, several scientific announcements increased the sense of urgency. In particular, in 1980 a team claimed to have discovered a quadrupole effect in the cosmic background radiation (one of the things Smoot hoped to find with COBE, a quadrupole effect, two warm and two cold regions of the cosmic background radiation, is not an illusion caused by our motion through the universe, as a dipole effect is, and would be evidence of density fluctuations at the time of decoupling), and in 1987 a team released findings that apparently discredited the big bang theory. Both findings were proved to be mistakes, but they nevertheless intensified the pressure on the COBE team. On November 18, 1989 the $160 million COBE satellite was launched from Vandenberg Air Force Base in California. Controlled from Goddard, COBE travels about 16,800 miles per hour in a polar orbit about 560 miles above Earth and completes a survey of the sky every six months.

The first important discovery, that the cosmic background radiation definitely came from the big bang, came from FIRAS. The radiation measured by FIRAS perfectly matched a graph predicting what radiation from the big bang should look like. In early 1991 a quadrupole effect became evident in the data from the DMRs, and by the fall of the year, evidence of smaller ripples, or wrinkles, of temperature fluctuations had been detected by Smoot's team. In light of the many discoveries that had been proved a mistake, Smoot was obsessive about detecting possible causes of error and demanded absolute secrecy until he was sure that were seeing what they thought they were seeing instead of signals from the sun, moon, galaxy, the instruments themselves, or anything else. To inspire diligence in seeking errors, Smoot offered anyone on the team a free plane ticket to anywhere in the world if they could prove a mistake had been made.

The scientific community grew restless waiting for the results, and there were heated arguments among the COBE Team about whether the findings were ready for publication. By October 1991 Smoot had become convinced the analysis was correct, but he wanted to check for one more possible source of error: distortion from radio interference from our galaxy. There were already maps of our galaxy's microwave emissions, but if they were wrong, then so was the DMRs' data. Therefore, in November Smoot led a team to Antarctica for a month to make a celestial map themselves. Antarctica was chosen because in the cold, dry air there has less interference from earthly signals, but even though it was summer and the sun never set, the working conditions were literally deadly as the oxygen was thin and the temperature could easily reach seventy-five degrees Fahrenheit below zero. Withstanding the elements, they confirmed previous celestial maps, and after Smoot's return, at a meeting to brief NASA officials on the progress of COBE, he donned a tuxedo to announce that the COBE experiments were a success in terms of data quality, collection, and analysis, but he held back on what they found until the fluctuations could be examined more fully and characterized.

In Wrinkles in Time Smoot compared looking for the cosmic background radiation to "listening for a whisper during a noisy beach party while radios blare, waves crash, people yell, dogs bark, and dune buggies roar." Removing unwanted signals from the picture to identify temperature fluctuations of a mere 1/100,000 of a degree, they examined the hundreds of millions of measurements myriad ways. The team confirmed the dipole and the quadrupole with relative ease, but identifying the smaller wrinkles proved difficult. Finally, Smoot removed the quadrupole effect from the data and found wrinkles that fit predictions. To confirm his finding, he suggested to a graduate assistant, Charles Lineweaver, who was using a different version of the analysis program, to look at the data with the quadrupole removed, without telling him what he had found. When Lineweaver left the office in the early morning hours, he slipped his results under Smoot's door with the message: "Here are the plots you asked for. Eureka?"

After three more months of intensive work fine tuning the details, the team submitted manuscripts for publication in the Astrophysical Journal and prepared to announce the results at a meeting of the American Physical Society in Washington, D.C., on April 23, 1992. Speaking of those three months, during which he worked seven days a week, often late into the night and was commuting almost constantly between Berkeley and Greenbelt, Smoot told Tim Radford of the Guardian (May 12, 1992), "I didn't open my mail, I let my car insurance lapse, and I let everything slide, because I was just trying to make sure it was right." Adding to his nervousness was his knowledge that at the same meeting two other groups were scheduled to present evidence that there was no anisotropy. (It turned out that the other groups findings did not directly contradict those of the COBE team.) "I really am betting my career on this," Smoot told Donald Goldsmith of Discovery (October 1992).

Smoot led off the meeting and was followed by six other COBE members. By announcing that COBE had not only detected a quadrupole effect, the first evidence of structure in the early universe, but also smaller ripples in the temperature of the cosmic background radiation that are consistent with big bang theory, Smoot stunned the audience of scientists and touched off a media circus rarely seen at scientific conferences. Much of the excitement outside of the scientific world stemmed from Smoot's comment at the press conference that "if you're religious, it's like seeing God." Smoot did not intend to imply that the discovery offered proof of God's existence, but other scientists, nevertheless, added to the religious metaphors. Michael Turner, an astrophysicist at the University of Chicago, declared, "They have found the Holy Grail of cosmology," and Stephen Maran, the editor of the Astronomy and Astrophysics Encyclopedia, said "It's like Genesis." The commotion was capped off by a Newsweek headline reading "The Handwriting of God." In an interview with John Noble Wilford of the New York Times (May 5, 1992), Smoot elaborated on the statement: "It really is like finding the driving mechanism for the universe, and isn't that what God is? . . . What matters is the science. I want to leave the religious implications to theologians and to each person, and let them see how the findings fit into their idea of the universe."

Smoot believes the detected wrinkles, which measure a mere 31- millionths of a degree different in temperature, started as small lumps but over time expanded to the immense size that COBE observed. The denser areas of the early universe, which appear slightly cooler in the cosmic background radiation, would have had sufficient gravity to attract more matter, resulting in a snowball effect, in which more matter causes more gravity that attracts more matter, and the lumpy areas and voids become more and more defined. One problem, due to COBE's limited resolution (its resolution is seven degrees on the sky; the moon covers half a degree), is that the smallest wrinkles it discovered are larger than even the largest observed superclusters of galaxies. The appearance of wrinkles of varying sizes indicates the probability that smaller ones exist, and Smoot is working on two projects that may reveal wrinkles small enough to have formed the objects in the universe: the University of California Millimeter Wave Anisotropy Experiment (MAX) uses sensitive balloon-borne thermometers to measure the cosmic background radiation at a scale of one half degree, and he and an international group of collaborators have made a proposal for the Cosmic Background Radiation Anisotropy Satellite (COBRAS), which likewise would measure the radiation on a smaller scale than COBE.

The major importance of the COBE team's findings is that it gives quantitative measures for what had been merely speculation, providing firmer ground on which to base further study. The discovery of wrinkles neither confirms nor refutes many of the abundant variations of the big bang theory. Indeed, instead of weeding out the theories, the findings invigorated many theories, with scientists arguing over whether the wrinkles offer proof or refutation. Smoot and many other scientists have stated that the COBE data gives two theories, which can work together, particular weight: inflation and cold dark matter. The inflation theory, proposed in 1980 by Alan Guth of MIT, states that, less than one- trillionth of a second after initial explosion, the universe underwent a brief period (fractions of a second) of exponential expansion, from being smaller than a proton to at least ten meters across, before slowing to the steady rate it is expanding today. The expansion caused minute variations in space to grow into areas large enough (the wrinkles) for gravity to act on matter. According to the cold dark matter theory, as much as 99 percent of the universe may be made of an unknown type of matter that is invisible to us. Without the cold dark matter, there would have been insufficient gravity to form the structure of the universe in the time it has, meaning that other unknown forces must have been at work. The findings from COBE tend to fit predictions for inflation and cold dark matter, but there is definitely no consensus. In April 1993 Smoot offered another explanation for some of the wrinkles in space. While he still believes that many of them are caused by density fluctuations, he stated that as many as half may be caused by gravity waves, which were caused during the creation of spacetime less than one-millionth of one-millionth of a second into the big bang. The waves from the creation process were exaggerated during inflation and still distort space, including the microwaves measured by the DMRs, even today.

George Smoot, who is unmarried, has homes in Berkeley, California and in Greenbelt, Maryland, and he regularly commutes between the two. Often working seven days a week late into the night on the COBE project, he has had little free time, but when he does he enjoys cross-country skiing and discussing philosophy. He detailed the history of cosmology and his own experiences studying the universe in Wrinkles in Time (1993), written with Keay Davidson. Many scientists shy away from attention, but Smoot has used the publicity generated by the discovery of ripples in space to help further the goals of science. "I would be terribly embarrassed by the publicity if it weren't for the fact that I thought I was doing some good," Smoot told Donald Goldsmith. "Here's a story about science, about good science, that doesn't offend religion, that doesn't offend a lot of things, that's not going to be used to trash the environment. I already heard from one of my cousins that her kids want to be scientists now, because you get to be famous and you get to discover the universe."

Selected Biographical References: Guardian p3 My 12 '92 por; N Y Times C p1+ My 5 '92 por; People 37:105+ My 25 '92 pors; Smoot, George, and Keay Davidson. Wrinkles in Time; Who's Who in America