From Maxwell to Higgs
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newsletter OF THE James Clerk Maxwell Foundation Issue No.4 Spring 20 14 From Maxwell to Higgs by Alan Walker, MBE, FInstP, BSc, Honorary Fellow School of Physics and Astronomy, University of Edinburgh Higgs found Professor James Forbes At about 3.00pm on the afternoon of John Clerk Maxwell, Maxwell’s father, an Tuesday 8 October 2013, a car pulled to advocate and Fellow of the Royal Society a halt in Heriot Row in Edinburgh. An of Edinburgh, probably took young James ex-neighbour got out and raced across to along to meetings there. At the age of 14, street to intercept Professor Emeritus Maxwell authored a paper ‘On Oval Peter Ware Higgs walking home. She Curves’ which in 1845 was read to the stopped him and said “Congratulations! Royal Society of Edinburgh on his behalf My daughter just called me from London by Professor James Forbes. Maxwell and told me about your award!” to which attended the University of Edinburgh Peter Higgs replied “What award?” This where one of his mentors was the same was the moment when Peter Higgs first James Forbes. After three years at heard that the Nobel Foundation had Edinburgh, Maxwell decided to complete awarded the 2013 Nobel Prize in Physics his degree at Cambridge. Professor Emeritus Peter Ware Higgs jointly between himself and the Belgian physicist Francois Englert. Cambridge as the better teacher. Maxwell offered Peter Guthrie Tait was already at to come to Edinburgh unpaid but the Maxwell’s territory Peterhouse College, Cambridge when University turned this offer down! James Clerk Maxwell was born on Clerk Maxwell came to Cambridge. In Kings College London 1852, Tait became Senior Wrangler at 13 June 1831 at 14 India Street in In 1860, Maxwell was however appointed Cambridge whilst, in 1854, Maxwell Edinburgh’s New Town, by coincidence to a chair at Kings College, London. became Second Wrangler. They both a short distance from Peter Higgs’ During his time there he published won the Smith’s Prize. Maxwell became home since 1967. In 1841, James’s father research on the theory of colour, the a Fellow of Trinity College in 1855. decided to send James to the Edinburgh dynamics of the electromagnetic field Academy to complete his schooling. and the kinetic theory of gases. During that time James stayed with his Aberdeen aunt Isabella Wedderburn at 31 Heriot In 1856, Maxwell was appointed Maxwell’s Row, the very same street where our Professor of Natural Philosophy at Electromagnetism tale began. Marischal College, Aberdeen. Despite having married the Principal’s daughter, In 1865, Maxwell resigned from Kings Katherine Dewar, he was made College, London and returned to Glenlair, Peter Gu thrie Tait redundant when, in 1860, Marischal where he wrote most of his ‘Treatise on The secretary to the Duke of Buccleuch College merged with King’s College to Electricity and Magnetism’ . In March 1871, sent his son, Peter Guthrie Tait, to form the University of Aberdeen. Maxwell was appointed to a Chair of Edinburgh Academy and, although they However, James Forbes had recently Experimental Physics and to the were of the same age, Maxwell ended up accepted the post of Principal of Directorship of the Cavendish Laboratory in a class a year ahead. They struck up a St. Andrews College (later the University) at Cambridge. Sadly, Maxwell died of friendship that was to last for the rest of and his chair at Edinburgh became cancer on 5 November 1879. Maxwell’s life. vacant. Maxwell was unsuccessful and Tait was appointed because he was seen newslette r OF THE James Clerk Maxwell Foundation The Tait Chair chemistry and mathematics than physics, successful and in particular Jeffrey of Natural Philosophy Peter took up theoretical physics on his Goldstone, then of Trinity College, arrival at Kings College, London where Cambridge showed that in such models Tait made a great success of his time at got a First Class degree in 1950. He then there would exist zero mass scalar Edinburgh and died at the age of 70 in completed an MSc and a PhD in what he particles. This work was published jointly 1901. During his time there, he worked on himself describes as theoretical quantum with Abdus Salam and Steven Weinberg quaternions, knot theory and the physics chemistry. who re-appear in this story later. This of golf. At his death, he bequeathed In 1949, Peter and a fellow undergraduate became known as the Goldstone Theorem funds to set up a lectureship in natural and was a serious problem for the Nambu philosophy and, in 1925, this was hitchhiked to the Scottish Highlands and they found themselves in Edinburgh. programme as such massless spin-less converted into the Tait Chair of Natural particles would be easily found and would Philosophy. The first incumbent was Peter immediately fell in love with the city. He was awarded an 1851 Exhibition be more readily emitted by stars than Charles Galton Darwin, the grandson of photons. the Charles Darwin. When he took up the Senior Postdoctoral Studentship and in post of Master of Christ’s College in 1954 – 56 spent part of his time at the University of Edinburgh. He subsequently A symmetric bowl Cambridge in 1936, he nominated his Imagine you have a bowl that has a shape successor to be Professor Max Born, one spent time as an ICI Fellow at Imperial College in London and was disappointed that is rounded and not flat at the bottom of the founding fathers of quantum and is symmetric about an axis through theory. Max Born had found his way to at not being able work with Abdus Salam. In 1960, after a temporary lectureship at its centre. You can rotate such a bowl Cambridge after being driven out of around that axis and it always looks the Germany by National Socialism. Professor University College, London, he was appointed as a lecturer at the Tait Institute same. If you were to put in a small ball Nicholas Kemmer succeeded Max Born in bearing, it would sit at bottom. This is the 1952. In 1954, Max Born rather belatedly in Edinburgh headed by Nicholas Kemmer, Abdus Salam’s former supervisor . lowest energy state of that ball and rotating received a Nobel Prize in Physics for his the system about the symmetry axis does earlier contribution to the development Spontaneous not change anything. It still has the of quantum theory. symmetry breaking symmetry it started with. If we push the The Tait Institute Peter continued his interest in the ball away from the bottom of the bowl, of Mathematical Physics symmetries underlying many physical we have to do work to push it up the sides. phenomena. He took an interest in We have two distinct ways of doings this. In 1954, Nick Kemmer was instrumental condensed matter theory and, in Either E-W or N-S. Any other direction is in the establishment of the Tait Institute particular, in what is known as just a combination of these two. Since we of Mathematical Physics across the spontaneous symmetry breaking in do work in both cases this corresponds, road from the Department of Natural systems such as ferromagnets and in what we talk about later, to two Philosophy. In 1966, Kemmer’s post was superconductors. In a ferromagnet, the massive scalar particle modes. renamed the Tait Chair of Mathematical iron atoms behave like dipole magnets Physics. with north and south poles at opposite The wine-bottle or ends, rather like compass needles. In a Mexican hat potential Peter Ware Higgs system above the Curie temperature, The particular shape of the bowl we have Peter Ware Higgs was born in the Elswick these magnetic dipoles are randomly just been discussing will depend on two district of Newcastle on 29 May 1929. oriented and the overall magnetization parameters, which, in the above case, we His father Thomas Higgs graduated disappears. Thus, above the Curie can take to be both positive numbers. If, from Bristol and joined the BBC as a radio temperature, rotating such a ferromagnet however, we make one of these parameters engineer. He was moved to Newcastle makes no difference as it has a rotational negative, the bowl now takes on the shape where Peter was born. Peter’s mother, symmetry. However, below the Curie similar to that of a sombrero or, if you Gertrude Maud Coghill, came from an temperature, these elementary magnetic prefer, the bottom of a champagne bottle. Edinburgh family many of whom were dipoles may align themselves in a If we rotate about the symmetry axis, the eminent physicians. The paternal Higgs’ particular direction because this has system is still symmetric. However, if we ancestors came from Bristol and from the advantage of having lower energy. were to put into this our small ball bearing, surrounding Gloucestershire. The system itself still has the original then its lowest energy state is no longer in symmetry but the symmetry of the the centre but away from the centre at the Peter’s family moved from Newcastle to lowest energy state does not exhibit bottom of the depression or trough in the Birmingham when he was about a year the same symmetry. It now has a bottle or hat. This ball bearing will have old. Early in WWII, he moved to Bristol ‘spontaneously’ chosen preferred chosen to sit at some angle in the trough with his mother. In Bristol, he attended direction breaking that symmetry. and, when we turn the bottle or hat about Cotham School and was fascinated by the its symmetry axis, the lowest energy state name, Paul Dirac, that appeared frequently The Goldstone Theorem chosen by the ball bearing will move with on the honours boards.