Our conversation with John Mather, Nobel laureate and FiO keynote speaker.
When asked about the key to his success, John Mather humbly replies, “The main thread of my life is that I’m willing to try the impossible; I have some faith that, if there’s no law of nature against success, then it’s worth trying.”
Mather began weaving a tapestry of discovery at an early age. Growing up on a farm in rural New Jersey, Mather, who is now a senior astrophysicist at NASA and the 2006 Nobel Prize co-winner in physics, performed scientific experiments in his home. He learned many of the fundamentals of research from his father, a researcher in animal husbandry and statistics. His love for science and his penchant for trying new things carry through more than 60 years later to his current work in infrared astronomy and cosmology, which have resulted in important discoveries about the origins of the universe.
Growing up, Mather explored the world through his love of reading and learning about science. His local library’s “Bookmobile” visited area farms every few weeks, and Mather borrowed several books each time it stopped. He often read about optics and saved his allowance to order lenses from Edmund Scientific so that he could assemble his own small refractor telescopes. He also frequently entered school science fairs, including one in which he kept eight baby rats in cages under his parents’ kitchen table, feeding them various diets to see which ones could best sustain them. His father showed him how to design a Greco-Latin square and to analyze the variance in the experiment. His results indicated that dog food and vitamins work well, while corn flakes were inadequate.
Mather earned his undergraduate degree in physics at Swarthmore College in Pennsylvania and went on to receive his doctorate at the University of California, Berkeley. There, he worked with Paul Richards, Charles Townes and Michael Werner on the newly discovered cosmic microwave background radiation. He first proposed his idea for the Cosmic Background Explorer (COBE)—the instrument that would eventually lead to the Nobel Prize—in 1974 while working as a National Research Council post-doctoral fellow at the Goddard Institute for Space Studies in New York. NASA accepted his team’s proposal to build the satellite and, by 1980, a team of scientists and engineers was working on the project at the NASA Goddard Space Flight Center in Greenbelt, Md.
COBE launched in 1989. After just nine minutes of observation, the instrument gave results showing that the cosmic microwave background followed a near-perfect blackbody spectrum; this confirmed the predictions of the Big Bang theory for this curve and verified what cosmologists suspected about the first moments of the universe. In addition, COBE provided a map of the very small temperature variation in the cosmic microwave background (anisotropy), which demonstrates how matter began to accumulate to form stars, planets and galaxies. Mather and colleague George Smoot of the University of California, Berkeley, won the Nobel Prize for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation.
The COBE team depended on cutting-edge optical technology for their measurement instruments, including the far infrared absolute spectrophotometer, for which Mather served as principal investigator. “We developed methods for extraordinarily accurate photometric calibration, using a full-beam blackbody to replace the sky,” Mather says. They also designed a differential photometer that could achieve the needed accuracy and a multiband IR photometer to map the entire sky in a search for the cosmic infrared background radiation. “We pushed the state of the art for IR detectors quite far, though by now the detectors would all be obsolete.”
Mather says several factors contributed to the ultimate success of COBE: The topic was vitally important; the innovation was capable of pushing the state of the art; and a dedicated team of engineers and scientists worked very closely together. Finally, he doesn’t discount cosmic luck. “Nature gave an anisotropy signal at just a level that was barely detectable with our equipment.”
Twenty years after the launch of the COBE satellite, Mather is once again leading a team of scientists and engineers preparing to launch a space-based mission that will explore the origins of the universe—the successor to the Hubble called the James Webb Space Telescope (JWST). Mather serves as the senior project scientist for JWST, a sort of liaison between the scientists and engineers working on the project. “I work with the scientists to ensure that the objectives have been properly translated into engineering requirements, and with the engineers to ensure that they understand the requirements and can push back on those that are too difficult or too imprecisely stated,” he says.
According to Mather, brainstorming with colleagues about new missions is one of the most thrilling aspects of his job. One of his greatest success stories comes from the early days of designing COBE. Mather’s team discovered that they had a serious problem with cosmic rays hitting the detectors. “My colleague Harvey Moseley saw that, if the detectors could be made far more sensitive, they could turn a problem into a tool.” According to Mather, they are now the best technology for measuring the energy of individual X-ray photons with a resolving power of several thousand. In fact, entire NASA missions are now designed around this method, and the idea has been extended to the search for dark matter in laboratories as well.
Mather says the important thing to remember when exploring seemingly impossible ideas is that technical progress is so rapid that the “impossible” can become routine within a decade or two. But he also recommends that scientists be strategic about the areas in which they focus their efforts. “Being ingenious about something nobody cares about is not that much fun, but pushing the state of the art for a problem that everyone thinks is important but difficult is very rewarding.”
Angela Stark is the public relations coordinator at OSA.