John F. Clauser woke up in his California home to the news that he had been awarded a prestigious prize. He was one of three people to receive the prize for their work on quantumentanglement.

Clauser's experiments with particles of light helped to prove important elements of quantum mechanics.

Clauser said that everyone wanted to win a prize. I'm very pleased.

It wasn't always easy for Clauser to win the biggest prize in science.

Clauser was a graduate student at Columbia University in the 1960's. By chance, he found an article in the university library that helped shape his career and eventually led him to win a prestigious prize.

The article was written by John Stewart Bell and was published in the journal Physics in 1964. The phenomenon of quantumentanglement was at the center of the question.

When two or more particles link up in a certain way, their states remain linked even if they are not in the same place.

Imagine two particles flying off in opposite directions. The measurement of particle A will determine the measurement of particle B, if the particles are entangled.

Albert Einstein and his colleagues did not approve of this possibility in the 1930's. They argued that there is a part of reality that isn't accounted for in quantum mechanics.

Bell argued in his 1964 article that it was possible to experiment with quantum mechanics to see if they failed to describe reality. He called them hidden variables.

Bell thought about local variables. They only affect the setup in their immediate area. Clauser explained that the experimental parameters made in one box can't affect the experimental results in the other box.

Clauser decided to see if Bell's proposal would work. He was urged to reconsider by his advisor.

Clauser said the hardest part was to get the chance. Everyone told me that it wasn't possible.

The quantum laboratory 

Clauser was able to test Bell's proposal in 1972 while he was at Lawrence Berkeley National Laboratory. He collaborated with a student. They set up a lab full of equipment.

Clauser said that nobody had ever done this before. We had no money to do anything. Everything had to be built from the ground up. I got dirty, I got immersed in cutting oil, and I built a lot of electronics.

Clauser and Freedman were able to create a photon. The particles of light traveled into polarizing filters that Clauser and Freedman could use.

If the local and hidden variables were taken into account, a higher amount of photons would pass the filters.

The predictions of quantum mechanics were correct. They said in 1972 that the results were strong evidence against local hidden-variable theories.

A difficult start

Clauser's and Freedman's results were confirmed by two other people.

Clauser's work was in the 70s, Aspect's was in the 80s, and Zeilinger's was in the 90's. We improved the field in sequential order.

The impact of Clauser's experiment wasn't immediately noticed.

Clauser said things were hard. It was said that if you wanted to stop wasting time and money and start doing real physics, you should go out and measure some numbers.

It took 50 years for Clauser to win the prize. Stuart died in 2012

Clauser said that his associates are long dead. My claim to fame is that I have lived a long time.

Clauser said that if you prove something that everybody thinks is true, and you're the first one to do it, you probably won't be recognized for 50 years. The good news is that I had a great time doing this work.

Quantum reflections

The way for quantum computers and ciphers was paved by Clauser's and Freedman's experiments.

Clauser believes there is a more fundamental theory below quantum mechanics. I'm not sure what it is. I confess that I don't know what all of this means.

John F. Clauser's quotes have previously been published in an interview.