During his junior high days in Temple City, California, Kent Cullers ’71 spent countless hours maneuvering the dials on his ham radio in an effort to communicate with far-off people. In a sense, the ham radio became Cullers’ window to the world, enabling the youngster to experience distant peoples and places in much the same way as he experienced his own neighborhood—through his remarkable sense of hearing.

Blind since after birth, Cullers leaned heavily on his hearing to slake an unremitting thirst for interaction. Constantly honing his radio know-how and upgrading his equipment, he endeavored to stretch his communications horizons beyond oceans and continental boundaries. Eventually, his conversations reached half way around the globe—from Alaska to Africa—but they weren’t enough. For like most ham radio enthusiasts, Cullers always searched for an even more distant signal.

His game hasn’t changed, but over the years the playing field has expanded, going from global to stellar, and the stakes have multiplied. If Cullers achieves his lifelong goal and detects the most distant radio signal—the one he grubs the skies looking for—the discovery will leave an imprint on every earthbound individual forever. Not to mention a few born on another planet.

While the rest of us ply our tellurian trades, Cullers reconnoiters the stars looking for signs of intelligent life. He’s a key player on a team of National Aeronautics and Space Administration (NASA) scientists and engineers scanning the cosmos for radio signals and plotting the most sophisticated listening operation ever mounted to detect communications from distant civilizations.

The 10-year listening effort is scheduled to begin on Columbus Day in 1992—part of the nation’s commemoration of the Italian explorer’s discovery of America. It could cost $95 million, and it will bear the mark of one of Pomona’s top physics graduates and the first blind person to receive a Ph.D. in physics from an American university.

Cullers, one of the nation’s leading signal processors, is busy programming SETI (Search for Extraterrestrial Intelligence) project computers at the Ames Research Center in Mountain View, California. His programs enable the computers to differentiate signals given off by microwave transmitters, aircraft, satellites, and other earthly devices, as well as random noise from distant space.

The aggregate of earthly signals contaminating ever-increasing numbers of radio bands poses a major obstacle to recognizing other-worldly communications. “It is imperative that we perfect our signal-finding techniques quickly, notably the techniques that work against the background of radio frequency interference,” says Cullers. “If we are going to detect from earth what signals might be coming from distant civilizations in space, we must do so before we have to move beyond our own interference by placing an antenna somewhere in space—probably the backside of the moon.”
The cost of erecting a lunar antenna would be staggering; thus NASA’s plans for a concentrated earth-fixed effort beginning in 1992. That effort will involve computerized searches by teams based at Ames and the Jet Propulsion Laboratory in Pasadena. The Ames group will concentrate on 773 solar-type stars within 80 light years, surveying the narrow low-frequency microwave window, the region of minimal galactic noise. The JPL crew will conduct a less sensitive full-sky survey, rapidly scanning the full dome of the heavens. The searches will use huge dishes in the United States, Canada, Australia, and Puerto Rico.

Antennas will receive signals and process them through computer-driven multichannel spectrum analyzers (MCSA), programmed to sort out and eliminate all the garbage noise from earth and space and to identify any intentional or unintentional signals aimed at earth from outer space.

Programming the computers with signal detection procedures is Cullers’ job. It’s something he came to out of a love of radio communications, a near lifelong desire to work for NASA, and a topflight physics education.

“For as long as I can remember I have been a ham radio enthusiast, trying to pick up signals from around the earth, and one of my ambitions through the years has been to detect the most distant radio signal I could find,” says Cullers.

Hooked on NASA
Cullers became interested in NASA’s SETI program in graduate school at UC Berkeley when his wife, Carol, read him a copy of Project Cyclops, a report of a design study of a system for detecting extraterrestrial intelligent life. The study was headed by Bernard M. Oliver, a winner of the National Medal of Science. Oliver, now chief of the SETI office and Cullers’ boss, used the report to propose in detail the design and development of transmission, receiving, and processing systems for searching the microwave window for signals from distant civilizations.

“I was amazed and fascinated, in fact, hooked,” says Cullers. “I visited NASA/Ames while still a student at Berkeley and made friends with several SETI scientists.” He also happened into Jill Tarter of the NASA/SETI project at a wedding reception and their conversation led to a job shortly after Cullers received his Ph.D. in space physics in 1980.

And for nearly a decade Cullers has been drawing on his boundless imagination, his knowledge of radio signals, and his mathematics expertise to program computers to detect extraterrestrial signals against the background of cosmic noise and spurious earthly radio signals. The computers must be especially fast, both because the incoming data rate is very high and because the computers are only able to store briefly the oceans of stellar data they’ll be fed.

“The computers are sorting through mountains of gibberish, looking for that one small signal,” says Cullers. “The galaxy has billions of stars, and we will attempt to sample as many of them as possible during the 10-year study. This is just the first step along what could be a very long road.”

Despite the enormity of the task, Cullers remains optimistic SETI scientists will find what they’re looking for.
“I am utterly convinced there is life out there. It is absurd to think that if we are the outgrowth of normal physical conditions in the universe, there is not other life out there,” says Cullers. “That doesn’t mean it’s going to be easy to find. We would not see another planet the size of earth with present telescopes, even if it were orbiting the nearest star to us; but we could find it by radio. Right now that is the only way we could. Rocket searches are just beyond our capabilities—cost- and technology-wise—at this time.

“I think it would be a mistake not to use the technology we have at hand to search for other civilizations like ours. If we do we’ll know a great deal about how life came to be in the universe and we will have proved it overnight.”

The odds appear to be stacked heavily against NASA scientists locating and identifying that one set of intelligent signals from space, considering the billions of different frequencies the could use and the constant babble of interfering radio noise from earth. But Cullers and his colleagues are believers.

“Most of us probably would not be involved in this if we didn’t believe strongly in the likelihood of finding what we are looking for,” he says.

Culling Signals
If the signals Cullers and his colleagues are searching for is out there, pulsing away, how will SETI scientists or other cosmos detectives recognize it?

“It will be easily distinguishable from natural and interference sources, a clear signal with certain intelligent transmission characteristics that we will recognize,” says Cullers. “We know that signals are easier to find when they are concentrated in frequency and time, and we know another intelligent civilization would know the same thing. We are likely to be dealing with a civilization that is far advanced compared to ours in terms of its discovery and utilization of radio.”

In short, the signal will probably be narrow band and continuous or regularly pulsed and transmitted on a single frequency, according to Cullers. The Ames-based search is designed to focus on a signal with those strongly defined components.

Over the years, Cullers has designed most of SETI’s detection systems, including those for both the big NASA fishing trips that get underway in 1992. His most recent contribution, introduced at a SETI staff meeting in December, is a technique for measuring the constancy of the rate of frequency change in a signal traveling in space.

The test, if it proved successful, could represent a breakthrough in detection techniques, doubling the sensitivity while increasing the system cost by only a few percent. It has been through years in coming and is a good example of Cullers’ value to the SETI team, according to Oliver, who says Cullers’ colleagues at SETI “don’t consider him in any way handicapped.”

That’s probably because Cullers has never seen himself as handicapped. Overexposure in an incubator to pure oxygen as a premature baby destroyed his retinas, but as a child he was encouraged by his parent to play like an ordinary kid. He made up for his sightlessness by cultivating heightened senses of tough and hearing. He climbed trees, roller-skated, rode a bicycle, played baseball (his playmates bounced the ball to him, so he could judge its position by sound and catch or hit it), and excelled at judo.

“His capacity to visualize abstractions never ceases to amaze me. Kent is certainly at the forefront of his field. The things he is doing are original and extremely valuable to our efforts,” says Oliver. “And the delightful thing about Kent is that he doesn’t appear to know he is blind. He has traded sight for insight.”

Blindness No Handicap
In an effort to minimize his sightlessness and build on his normalcy, Kent’s parents, Wanda and George Cullers, moved in 1955 from El Reno, Oklahoma, to Temple City, where blind children were being mainstreamed in the public schools.

Cullers’ father went from oilfield engineer to aeronautical engineer and his company, North American Rockwell, rewarded Kent’s outstanding high school academic achievements with a college scholarship, which he combined with a California state scholarship to attend Pomona.

“I wanted to major in psychology and Pomona had an outstanding program. Back then I thought I’d like to unlock the mysteries of the mind,” says Cullers. But a growing interest in physics forced a decision midway through his college career, and Cullers chose physics. The choice turned out to be the path of greatest resistance.

Along the way, Cullers has had to master seven distinct Braille languages and several computer tongues and become adept at manipulating a wide range of electronic gadgets. It helps that he has world-class patience and a positive attitude that tests the imagination.

Where many people would harbor an abiding resentment for the conditions of fate that left them sightless, Cullers remains grateful that it happened at a time when the world was being overtaken by electronics.

“Without the electronic revolution and the computer age, I wouldn’t be able to take an aptitude for math and physics and a good education and, with the aid of computer technology, parlay them into a career as an experimental physicist,” says Cullers. “In high school they told me I should be either a pianist or a lawyer.”

Consider that physics is taught largely at the blackboard and you begin to realize the hardships involved in Cullers’ schooling. His remarkable listening skills and sagacity for mental math carried him through his undergraduate studies, and those laid a solid foundation for graduate work at Berkeley.

“In a way, physics in graduate school was easier than physics at Pomona. My Pomona professors always gave extremely difficult examinations. You could only expect to get half the answers correct, no matter how well prepared you were,” says Cullers. “Those tough examinations and the personal attention every student received were excellent preparation for graduate study.”

The challenges continued throughout Cullers’ years at Berkeley, where professors cut him not slack (“50 percent of the class was suppose to flunk out, and for a while I was expected to be a part of that group”).

“But I managed to borrow enough class notes and get enough assistance from classmates to keep up,” says Cullers, who graduated in the top 10 percent of his UC Berkeley class.

As he progressed further into his physics education and the march of computer/electronics technology proceeded, Cullers connected to one piece of machinery after another. He takes three computers home every night and Cullers’ Ames office, Room 207 of Building N229 at Moffett Field, is a machine fortress. Braille’N Speak is attached to a Keynote laptop computer, which is attached to a Versa Brailler, which is attached to a Leading Edge computer, and so on. There’s a Crammer Modified Perkins Brailler, an Apple II computer, a Braille terminal, a reel-to-reel tape recorder, and an integrated telephone answering machine. All the hardware it takes for a signal processor to crank out his work.

Juxtaposed to all that high-voltage paraphernalia is an old wooden rocking chair that Cullers refers to has “the most important piece of equipment I own”.

It’s a favorite seat and the spot we can assume he conjures up those “brilliant thoughts” his boss, Barney Oliver, refers to—the ones that will enable SETI scientists someday to answer the phone when E.T. calls.

Tipped off to Kent Cullers’ work by an article in the August 1988 California magazine, Wood, associate editor of Pomona College Today, visited Cullers at the Ames Research Center in December.

—Tom Wood
Spring 1989, Pomona College Today