Subatomic particles can be linked to each other even if separated by billions of light-years of space.
But this strange and spooky phenomenon hadn’t been proven until Walnut Creek-based physicist John Clauser performed a pioneering experiment at UC-Berkeley in 1972 – an accomplishment that on Tuesday was honored with the Nobel Prize in Physics.
Clauser, 79, shares the $900,000 prize with two fellow physicists who followed in his footsteps: Alain Aspect of Université Paris-Saclay and École Polytechnique in France, and Anton Zeilinger, of the University of Vienna in Austria.
This discovery, now a core concept of quantum mechanics, could revolutionize computing, cryptography and the transfer of information via what is known as “quantum teleportation,” according to the Nobel committee.
Working independently, the three scientists conducted experiments that demonstrated “quantum entanglement,” an odd phenomenon in which one particle can instantaneously influence the behavior of other particles — even if they are far away, such as at opposite sides of the universe.
Clauser’s work measured the behavior of pairs of tiny photons, which were “entangled,” or acting in concert. It showed, in essence, that nature is capable of sending signals faster than the speed of light.
This phenomenon, the foundation of today’s quantum computers and other modern quantum technologies, is so weird that physicist Albert Einstein called it “spooky action at a distance.”
“Today we honor three physicists whose pioneering experiments showed us that the strange quantum world of entanglement… is not just the microworld of atoms, and certainly not a virtual world of mysticism or science fiction, but the real world we live in,” said Thors Hans Hansson of the Nobel Committee for Physics during a news conference in Stockholm.
Clauser, now retired, spends his days racing his 40-foot yacht Bodacious in San Francisco Bay, “the greatest place in the world for sailing.”
In an interview Tuesday, he told the Bay Area News Group he was thrilled by the 3 a.m. news from Stockholm and the tsunami of congratulatory calls. “It took me over an hour to get my pants on,” he joked.
Clauser, born a year after Pearl Harbor in 1942, grew up in the suburbs of Baltimore where his father had been hired to create Johns Hopkins University’s aeronautics department.
He credits his father with his love of electronic tinkering, an essential skill for future experimental discoveries.
After school, when he was supposed to be doing homework, “mostly what I would do is just sort of wander around the lab and gawk at all of the nifty laboratory equipment,” he said in an oral history recorded by the American Physics Institute.
Say hello to our newest physics laureate John Clauser who took this photo just a few moments ago!
In addition to his work on quantum mechanics, Clauser is an avid sailer who has filled multiple patents to increase aerodynamic efficiency of boom-footed sails.#NobelPrize pic.twitter.com/EPG07Bsum1
— The Nobel Prize (@NobelPrize) October 4, 2022
“My dad was absolutely a marvelous teacher, my whole formative years,” he recalled. “Every time I asked a question, he knew the answer and would answer it in gory detail so that I would understand it. I mean, he didn’t force feed me, but he did it in such a way that I continuously hungered for more.”
Clauser first came to California in the early 1960s to study physics at the California Institute of Technology, then earned his PhD at Columbia University.
The study of Advanced Quantum Mechanics – a field he would later revolutionize – initially daunted him. He didn’t understand its mathematical manipulations, and repeated the class three times before earning the requisite B grade.
“I just didn’t really believe it all. I was convinced that there were things that were wrong,” he said. “My Dad had always taught me, ‘Son, look at the data. People will have lots of fancy theories, but always go back to the original data and see if you come to the same conclusions.’ Whenever I do that, I come up with very different conclusions.”
That skepticism paved the way for his future Nobel. While working at UC Berkeley, he stumbled upon a fascinating theory by Northern Irish physicist John Stewart Bell, which explored what entanglement’s “spooky action” said about photons’ behavior and the fundamental nature of reality.
“But where’s the experimental evidence?” Clauser wondered. He knew Bell’s theorem could be tested.
He told PBS’s Nova how he rummaged around the hidden storage rooms of Lawrence Berkeley National Laboratory, scavenging for old equipment to design the experiments he needed.
“There are two kinds of people, really. Those who kind of like to use old junk and/or build it themselves from scratch. And those who go out and buy shiny new boxes,” he said. “I’ve gotten pretty good at dumpster diving.”
He faced criticism from many fellow physicists. “Everybody told me I was crazy, and I was going ruin my career” by wasting his time on such a philosophical question, he recalled.
In an experiment in the sub-basement of UC Berkeley’s Birge Hall, conducted alongside the late fundamental physicist Stuart Freedman, he measured “quantum entanglement” by firing thousands of photons in opposite directions. They showed that the photons could act in concert — despite being physically separated.
This year’s #NobelPrize laureate John Clauser built an apparatus that emitted two entangled photons at a time, each towards a filter that tested their polarisation. The result was a clear violation of a Bell inequality and agreed with the predictions of quantum mechanics. pic.twitter.com/q9WJIYMhhe
— The Nobel Prize (@NobelPrize) October 4, 2022
“The experiment…was so novel that it was completely underappreciated at the time,” said Berkeley Lab Director Mike Witherell. “It was 10 years before physicists started to realize how quantum entanglement could be exploited. That was when the next decisive experiments were done, leading to the new quantum era we are now experiencing.”
Unable to find a job as a professor, Clauser moved to Lawrence Livermore National Laboratory to do controlled fusion plasma physics experiments but later left because he refused to do classified work.
His insights are now the scientific underpinning for today’s efforts to develop quantum cryptography, a method of encryption that uses the properties of quantum mechanics to secure and transmit data in a way that cannot be hacked.
Such powerful commercial applications were inconceivable at the time, he said.
“I was totally unaware of how much money and interest there was in cryptography,” he said. “Heck, most of my computers didn’t even require passwords. The only reason I have them on now is because we have all of the ones in the house all networked, and you can’t put it on a network without putting passwords on them. “
