Bell’s Theorem Crescent

20 February 2015

Belfast-born physicist, John Bell, has been honoured in his home city with a street named for him and his seminal discovery – Bell’s Theorem Crescent.

Bell’s Theorem Crescent
Credit: Northern Ireland Science Festival
Aidan Browne, Belfast Met and Lord Mayor of Belfast, Nicola Mallon

The naming ceremony at the Belfast Metropolitan College in the Titanic Quarter was also the opening event of Northern Ireland’s first Science Festival. The Lord Mayor of Belfast, Councillor, Nicola Mallon cut the ribbon at the event which was organized jointly by the Institute of Physics in Ireland, Belfast Met, Northern Ireland Science Park, Titanic Quarter, Queen’s University Belfast and the Royal Irish Academy.

Born in 1928 in Tates Avenue, Belfast, John Stewart Bell attended the Belfast Technical College which was the fore runner for Belfast Met. Trained as a technician we worked in the physics department at Queen’s University Belfast where he used his earnings to fund his degree studies at QUB. He took his PhD at Birmingham University and then worked at CERN - becoming one of the world's leading physicists, breathing new life into the foundations of quantum theory.

Bell formulated a theorem that physicists now consider to be one of the most significant developments in quantum theory. His proof of non-locality, which was published on 4 November 1964, revolutionized the understanding of quantum theory and the nature of the physical universe.

Speaking at the event, Aidan Browne of Belfast Met, welcomed many members of John Bell’s family to the event, including his sister Ruby McConkey and brother Robert Bell,  while Basil McCrea, MLA and Chair of the All-Party Group on Science at the N. Ireland Assembly noted the impact which Bell’s work has had on local companies such as Andor Technology.

Bell’s Theorem Crescent
Credit: Northern Ireland Science Festival

Dr Joanne Stuart, Director of Development at the N. Ireland Science Park outlined Bell’s Belfast roots and his path to world-renowned physicist while the group also heard from a physics student at Belfast Met, Nick Long who outlined his own passion for engineering and technology.

The background to Bell’s Theorem goes back to the late 1930s and Albert Einstein’s dislike of quantum mechanics, which he argued required “spooky actions at a distance”. According to quantum theory, a measurement in one location can influence the state of a system in another location. Einstein believed this appeared to occur only because the quantum description was not complete.

The argument as to whether quantum mechanics is indeed a complete description of reality continued for several decades until Bell, who was on leave from CERN at the time, wrote down what has become known as Bell’s theorem. Importantly, he provided an experimentally testable relationship between measurements that would confirm or refute the disliked “action at a distance”.

In the 1970s, experiments began to test Bell’s theorem, confirming quantum theory and at the same time establishing the base for what has now become major area of science and technology, with important applications, for example, in quantum cryptography, quantum computing and quantum teleportation - set to become some of the most important growth areas in science in the 21st century.

At the time of his death in 1990, Bell had been nominated for a Nobel Prize, which he was expected to win. That would have entirely changed Bell’s legacy. He is well remembered by many working on the foundations of quantum mechanics but not well known by people in other areas.

Liz Conlon, Education and Outreach advisor for IOP Ireland and chair of the N. Ireland Science Festival, noted: “The Institute of Physics cites John Bell as one of the top ten physicists of the 20th century, he came up with an answer when Einstein couldn't - we are honoured to have a luminary of his incredible standing as one of our own”. She continued: “The physics base in Northern Ireland is worth £1.5 billion to the local economy and supports nearly 27,000 jobs”.

It was appropriate that passing by Bell’s Theorem Crescent at the time of the event was a local city bus, carrying an IOP Ireland poster noting the breadth of jobs for physicists.