But by carrying out his work in the 1970s, he actually hoped to prove the opposite, and to prove Albert Einstein right, who did not believe in this phenomenon, said John Clauser in a telephone interview with AFP.

"The truth is, I really hoped Einstein would win, which would have meant quantum mechanics was giving incorrect predictions," the 79-year-old researcher said from his home in Walnut Creek, near San Francisco in the US. -United.

Born in Pasadena in 1942, Mr. Clauser links his love for science to his father, founder of the Department of Aeronautics at Johns Hopkins University in Baltimore.

"I was walking around his lab and I was like 'wow, when I grow up I want to be a scientist so I can have fun with these toys too'," he said.

As a student at Columbia University in the mid-1960s, he developed an interest in quantum physics, at the same time as a thesis in radio astronomy.

"Wacky"

According to quantum mechanics, two photons of light can be "entangled": what affects one immediately affects the other, even at a great distance.

The fact that this can happen simultaneously contradicts Einstein's theory of relativity that nothing can travel faster than light.

In 1935, Albert Einstein called this entanglement a "frightening effect at a distance".

Albert Einstein believes that as yet unknown "hidden variables" were at play -- a debate that sparked controversy with his friend but intellectual opponent Niels Bohr, one of the fathers of quantum physics.

In 1964, physicist John Bell proposed a theoretical means of verifying whether hidden variables were actually at work.

John Clauser then realizes that it is possible to resolve the long confrontation between Einstein and Bohr by creating the right experiment.

“My thesis supervisor thought it was a distraction from my work in astrophysics,” he recalls.

But after having written to John Bell, this one encourages him to continue his attempt.

Mr. Clauser was only able to begin to really work on his experience after taking a position at UC Berkeley, working with the now deceased Stuart Freedman.

By aiming a laser at calcium atoms, pairs of entangled photons are emitted in opposite directions, and are then measured to determine whether or not they are correlated.

After hundreds of thousands of tests, the two men are convinced to have proven the reality of this "frightening" phenomenon.

At the time, some prominent figures were unimpressed, including renowned physicist Richard Feynman, who told John Clauser that his work was "completely wacky" and "wasting everyone's time and money ".

Questioning the foundations of quantum mechanics was then not seen as necessary.

Practical applications

The Nobel Prize committee did not share this opinion, and awarded the physics prize to John Clauser, alongside the Frenchman Alain Aspect and the Austrian Anton Zeilinger, for their pioneering work in this field.

“It took time for people to realize the importance of this work,” says the American.

"I thought it was important at the time I did it, and I was having fun doing these things in physics," he recalls.

But being rewarded is finally "proof" that he was right.

John Clauser says he felt more attracted to the physics of Albert Einstein than that of Niels Bohr.

But over time, he realized the real value of his experience and that of his co-winners.

Having demonstrated that information can be distributed in space is today what allows the development of quantum computers.

And to quote the Chinese communications satellite Micius, using this quantum theory by relying on entangled photons located thousands of kilometers away.

"We haven't proven what quantum mechanics is -- we've proven what it isn't," says John Clauser.

"And knowing what it is not allows for practical applications."

© 2022 AFP