By Matin Durrani
This year marks the 50th anniversary of the publication of a now-famous paper in the journal Physics by the Northern Irish physicist John Bell, in which he proved that making a measurement on one particle could instantaneously affect another particle – even if it’s a long way off.
As our regular columnist Robert P Crease writes in the November issue of Physics World magazine, that kind of instantaneous effect, which proved the concept of entanglement, was not something that Bell was originally keen on. In fact, Bell had actually set out to prove the opposite – that it was possible, using “hidden variables”, to have a theory of physics that could keep things nice and “local”, and so avoid what Einstein had dubbed “spooky action at a distance”.
But Bell reversed his thinking. “I made a phase transition in my mind,” he told Crease shortly before his death in 1990 aged 62.
Yesterday (4 November) marked the 50th anniversary of the day that Bell’s paper arrived at the journal’s offices and today (5 November) sees the opening of an exhibtion at the Naughton Gallery on the campus of Queen’s University Belfast, from which Bell graduated with a first-class degree in mathematical physics in 1949.
Entitled “Action at a distance”, the exhibition runs until 30 November and promises to “explore Bell’s life and the artistic response to his legacy by artists from across the world”. There is also an accompanying series of lectures from Andrew Whitaker, Maire O’Neill, Mauro Paternostro, Artur Ekert and Anton Zeilinger.
Anyway, just for fun, here are some facts about Bell taken from a feature article that Whitaker wrote for Physics World in 1998.
* John Bell was known by his middle name “Stewart” until he went to university and his childhood nickname was “The Prof”.
* He was a long-term vegetarian and in his version of Schrödinger’s cat paradox, the two states of the cat are being hungry or not hungry, rather than being dead or alive.
* Bell sported his trademark beard after a motorbike accident in his 20s left a deep cut around his mouth.
* He spent most of his career at CERN, where his day-job involved designing accelerators; quantum theory was just his “hobby”.
For more on the 50th anniversary of Bell’s theorem – including topical reviews and personal views on John Bell himself – check out a new special issue of Journal of Physics A.