by Peter Higgs, who gave his name to the sub-atomic particle known as the Higgs boson, died at the age of 94. He was always a modest man, especially when he considered himself one of the greats of physics of particles – the field of science concerned with the building blocks of matter.
In 1964, a few years after arriving in London to take up a post at Edinburgh University, Higgs read a paper by the American theoretical physicist Philip Anderson. At the time, physicists did not have a theory about how subatomic particles got their mass. (Mass can be described as the total amount of matter in an object, and weight is the force of gravity acting on an object.)
Anderson’s paper showed that particles can have mass. When a system in physics is changed – such as two different subatomic particles – physicists sometimes describe it as “broken symmetry”. This may lead to new properties.
During a walk in the Scottish Highlands, Higgs had the idea of a lifetime. He figured out exactly how to apply the symmetry breaking he read about in Anderson’s paper to an important group of particles called gauge bosons. It would lead to an explanation of how the building blocks of matter get their mass.
Two other groups of physicists had the same idea around the same time: Robert Brout and François Englert in Brussels, and Carl Hagen, Gerald Guralnik and Tom Kibble at Imperial College London.
An afterthought
The main distinguishing feature of Higgs’ work was that he predicted, as an afterthought, the existence of a new massive particle that had been produced by the process he had worked out in the Lowlands. This particle would later have its name: the Higgs boson.
I believe Higgs was always embarrassed that this symmetry breaking mechanism was sometimes shortened to “Higgs Mechanism”. He was always quick to point out what everyone else was saying, and he preferred the “Anderson-Brout-Englert-Higgs-Hagen-Guralnik-Kibble” mechanism.
In the next few years, it became clear how important the contribution of these scientists to our understanding of particle physics was – not least because the particle named after Higgs was not so obscure. Several machines, known as particle colliders, have been built to explore the limits of our knowledge in physics.
They explored and tested the most widely accepted theory to explain how elementary particles (those that cannot be broken down into other particles) and forces interact: the Standard Model. And the Standard Model was in almost every condition. The only missing ingredient, not found by a particle collider, was the giant particle predicted by the Higgs.
Frustration over the elusiveness of the Higgs boson prompted Nobel Prize-winning physicist Leon Lederman to come up with another monitor: the “Goddamn Particle”. This was later shortened to the “God Particle”.
It would take 48 years and the largest human machine ever, the Large Hadron Collider (LHC), to finally find evidence that Higgs and his colleagues were right. Cern, the organization that operates the LHC, announced that physicists were almost certain to have found the particle on July 4, 2012.
Further experiments confirmed that this was indeed the particle predicted by Higgs. But when it was time for the Nobel Prize in Physics to be announced in October 2013, Higgs went out for a walk instead of waiting on the phone.
The ‘fifth force’ of nature
It is now more than 10 years since the discovery of the Higgs boson. There is a big difference between just having a theory that (almost) everyone believes in, and finally having the evidence that it is, in fact, a good description of nature.
In fact, I’m not sure we still fully understand what Higgs and his colleagues brought to the world. It amounts to the discovery of a new interaction between particles that we had not seen before, known as Yukawa coupling. This is essentially a “fifth force” of nature to complement the gravitational force, the electromagnetic force, the strong nuclear force and the weak nuclear force.
However, there are many other issues to be resolved. Only 4% of the universe is made up of the matter we can see. The rest is dark matter and dark energy – but we don’t understand the nature of either. There is even a theoretical calculation that the Higgs boson is crucial to the stability of the universe.
The Cern Council has just reviewed the progress of a feasibility study to build a machine called the Future Circular Collider, which will succeed the LHC and aim to solve many unsolved questions about the nature of the universe. to answer, if allowed. I know where I’m trying to look for answers in the data of the collider: the Higgs boson.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Harald Fox receives funding from UKRI.
