Does it exist, what is its raison d'être - and do the answers lie in the stars?
The Higgs boson, also known as the God particle, was in the news lately. Two teams of scientists from the CERN laboratory in Geneva reported possible sightings of this elusive particle last week.
As a physicist who had a hand in formulating today's standard model of particle physics, I was asked about this. Does a God particle really exist, what is its raison d'être, why the unusual name?
I believe Rutherford would have urged caution. Rutherford arguably contributed more than any other person to our understanding of the structure of matter.
His discovery of the nuclear atom, with electrons orbiting a nucleus comprised of neutrons and protons, was based on irrefutable observations. Today's work is less secure.
Modern physics departed from Rutherford's world of certainty in the 1960s with the assumption that neutrons and protons are composed of even smaller particles, known as quarks, with unprecedented properties.
It was assumed, for instance, that quarks are permanently trapped inside the neutrons and protons they inhabit, and are therefore unavailable for study in isolation.
This differentiated them from the particles observed by Rutherford and his collaborators, and introduced uncertainty into the theory. Imagine trying to figure out how a grandfather clock works without being able to open the case.
In the theory, the quarks were initially introduced in pairs of identical twins. But in the world of particle physics, no two particles are identical. Nature does not repeat herself.
The neutron, for example, is slightly heavier than the proton. Also, their charges differ. Hence the Higgs boson.
It was introduced to break up the pairings by giving quarks different masses and charges. But the process was unpredictable, and some quarks (and other particles) ended up outweighing their partners by surprisingly large amounts.
Cubist paintings illustrate the process. These are usually interpreted as depicting multiple perspectives of a single subject. Taken literally, however, they appear to portray objects surprisingly asymmetrical when we expect symmetry. The process appears to be unpredictable, but of course it is not.
Behind the image there is the mind of a master painter. The standard theory is surprising on several counts besides those mentioned above.
Nevertheless, belief in it is strong, and the title 'God particle' that the Higgs boson has inherited is not entirely out of court.
But belief in science counts for little unless it is backed by observation. The data obtained at CERN during 2011 on the Higgs boson were not definitive. A significantly larger data sample will be gathered in 2012, and this may determine unequivocally whether or not the Higgs boson exists. Data from a rival laboratory in the United States will serve as a check.
Many have remarked that a negative result would be as interesting as a positive one. It would open the door for alternative ideas that were side-lined over the years, and encourage the development of new ones.
Other long-standing puzzles could be addressed. For example, the standard theory assumes the existence of 18 types of quarks, but most of these appear to be redundant. The nuclei of the chemical elements we are familiar with, from hydrogen to uranium, are comprised of just six types of quarks. The remaining 12 appear to be superfluous. Their existence is unexplained.
A speculative alternative to the experiments being conducted at CERN would be to listen for radio signals from a more advanced civilization, in the hope they might beam us a blueprint of their findings. Murray Gell-Mann, the inventor of the quark hypothesis, proposed this in 1995. At the time, no planets orbiting stars where life might exist had been found, and the idea seemed unlikely. However, more than 1000 "exoplanets" have since been found, and the idea is perhaps not completely far-fetched.
These and related ideas engage the interests of physicists worldwide. The author's experience with students at the University of Auckland suggests that breakthroughs could emerge anywhere on the globe. It will be interesting to learn if the God particle is still centre stage in the world of physics this time next year.
*Philip Yock is an associate professor of physics at Auckland University.