Many people who are involved in the physics community were not surprised by the announcement of the winners of this year’s Nobel Prize in physics last week. I wasn’t surprised either when I saw the names Francois Englert and Peter W. Higgs listed as the recipients. The word “Higgs” is familiar to pretty much everyone, not only those involved in physics.
The official description of the award from the Nobel Prize website: the Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider.”
So what exactly did these guys do? I’m sure we all remember the news headlines from July 2012 (Independence Day, actually) saying “The God Particle” had finally been detected. What is this particle, why is it significant, and how was it found?
One could say that the main objective of physics is to describe the universe in the simplest, most elegant way possible. Through centuries of work, physicists have been advancing this goal from all angles. The most significant advances, though, occur when some sort of unification is made. For example, Newton unified the laws of planetary motion with physical phenomena here on Earth (a huge accomplishment at the time, though obvious now.) Maxwell united electricity and magnetism into electromagnetism. Einstein unified mass and energy in his ever so famous formulation. The list goes on.
The hunt for one Grand Unified Theory has classified all forces in the universe into four categories: gravitational force, electromagnetic force, weak nuclear force and strong nuclear force. The weak nuclear force is involved in radioactive decay, and the strong nuclear force is responsible for holding together the atom’s nucleus. Three of these four forces, excluding the gravitational force, can be modeled by quantum mechanics. This isn’t the case for gravity, which is still described by continuous, or classical mechanics (albeit altered by Einstein’s general theory of relativity.)
One of the coolest attributes of the electromagnetic, strong, and weak forces is that each associates with an actual elementary particle. These particles are classified in what is known as The Standard Model of Particle Physics. The Standard Model was developed during the 20th century, and finalized in the 1970’s. So all is well and good; the Standard Model contains all of the fermions, the particles that compose matter, and the bosons, the particles that compose forces.
Except not really. The Standard Model falls short. Essentially, because the Standard Model fails to incorporate the full theory of gravitation, it has no way of attributing mass to particles. There was just no way to explain how particles acquire mass. Not until July 2012, at least. The experimental results announced last summer verified the Higgs Mechanism, originally proposed by the Laureates in 1964. This mechanism is the process that gives mass to the elementary particles through a transformation called spontaneous symmetry breaking.
On July 4th, two experimental groups working at the CERN Large Hadron Collider, the highest-energy particle collider ever created, broke the news. The collider has a 17 mile circumference, and is able to smash particles together at formerly unprecedented energies, at nearly the speed of light. The Standard Model predicts that the Higgs Boson will be formed any number of ways from certain collisions. In order to prove the theory wrong or right, scientists at CERN set off to find the elusive “God Particle.”
The choice of recipients for the Nobel Prize in physics wasn’t surprising, but that doesn’t mean it wasn’t controversial. There’s a bit of a problem with Nobel Prizes, especially in the sciences, due to the fact that one prize can be shared by a maximum of three people. The prize went to Englert and Higgs, the first two scientists to publish the idea, but what about Gerald Guralnik, Carl Richard Hagen and Tom Kibble, who developed the theory on their own and published it only a month later? Additionally, Englert had been working with the late Dr. Brout, who could have also shared in the prize, except for the fact that it is not awarded posthumously. Finally, and most importantly of all, what about those thousands of experimental scientists who devoted years of their lives to the pursuit of the Higgs Boson at the LHC?
Other Nobel Prizes have been awarded to entire organizations, but no such thing has happened in physics. And while some are bitter that the award wasn’t also presented to others who contributed to the discovery, most scientists respond affably. Young experimental physicists at CERN, for example, are excited just to be part of the Nobel-worthy success. According to some, experimentalists are used to missing out on the glory generally bestowed on theorists like Higgs and Englert.
Overall, the prize isn’t the important thing. Those who hold a romantic viewpoint when it comes to physics care more about the completion of the Standard Model; just one more achievement by amazingly smart, talented and passionate people in an effort to unify and understand the world around us.