The difficulty of trying to explain the hunt for the Higgs boson
shows that nature will not be so easily defined.
In the early 80s, the US decided to build a massive particle accelerator which was called – with typical American excess – the Superconducting Super Collider. During its early planning stages, the great machine was enthusiastically supported by the vast majority of US congressmen who each hoped the $4.4bn project would be based in his or her state, bringing jobs and prestige.
The Particle at the End of the Universe: The Hunt for the Higgs and the Discovery of a New World, by Sean Carroll
Texas was eventually selected to be the SCC’s home – at Waxahachie, near Dallas. Forty-nine out of the 50 state delegations in Congress promptly dropped their interest in the SSC, leaving it fighting for its life. The Nobel laureate (and SCC defender) Steven Weinberg subsequently appeared on radio with a congressman who wanted to stop the project. “I explained that the collider was going to help us learn the laws of nature and asked if that didn’t deserve a high priority,” Weinberg recalls. “I remember every word of his answer. It was ‘No’.”
A few months later the SSC was cancelled and so Europe took over responsibility for the next-generation collider that physicists said they needed. The Large Hadron Collider – built at the laboratories of Cern, near Geneva – eventually began operations in 2009 when scientists started smashing beams of protons into each other to seek new sub-atomic entities in the debris. Three years later, they found the Higgs boson, the fabled particle responsible for giving mass to objects. Peter Higgs, a Brit, and the Belgian François Englert, who first proposed the particle’s existence, subsequently shared the 2013 Nobel prize for physics.
Crucially, the LHC probably has another 20 years of use and further glories can be anticipated – though Sean Carroll makes it clear that these are unlikely to bring wealth or vast industrial returns. We construct machines such as the LHC, and try to uncover the building blocks of the cosmos, primarily as cultural exercises, he argues in The Particle at the End of the Universe. “Basic science might not lead to immediate improvements in national defence or a cure for cancer but it enriches our lives by teaching us something about the universe of which were are a part,” he tells us. “That should be a very high priority indeed.”
It is a fair point though it begs the simple question: just what have we learned from the billions of euros we have invested in particle physics? What cultural benefits have they brought? A great deal, says Carroll. We now know that sub-atomic particles come in two varieties: fermions that make up matter, and bosons that carry forces. The latter include gluons, photons, gravitons (which carry gravity) and of course the Higgs. The former, the fermions, include leptons such as the electron and quarks of which there are six types: up, down, charm, strange, top and bottom. On top of that we have issues of symmetry, force fields and wave functions.
And that, I am afraid to say, is just the start, for as Carroll makes abundantly and wearisomely clear, these particles, forces and processes combine in highly complex, intricate ways, often inducing numbing incomprehension in the process. “Whenever we have symmetry that allows us to do independent transformations at different points (a gauge symmetry), it automatically comes with a connection field that lets us compare what is going on at those locations,” we are told at one point. I confess the sentence makes no sense to me despite several readings. Nor is it the only chunk of Carroll prose that left me reeling in bafflement.
To be fair to the author, he is dealing with a subject of mind-spinning complexity. Things get messy, he admits. “It’s not supposed to be simple; we’re talking about a series of discoveries that resulted in multiple Nobel prizes,” he states.
It is a good point and Carroll does try to pace his book carefully – at least during the opening sections. New concepts are introduced with restraint and, by adopting a light, slightly gossipy style, he occasionally lightens the reader’s load. On the work of the experimentalists at Cern who strive day and night to drive their machines to the limits, he tells us that “occasionally they are allowed to visit their families, or see the sun, though such frivolities are kept to a minimum”. That perfectly captures the intense, massive collaboration – involving thousands of scientists – that was required to build and run the Large Hadron Collider.
Unfortunately, such levity makes only rare appearances in a book that is sadly disfigured by the over-weaning ambition, of an otherwise talented author, to write the definitive account of the laws of nature for the layman. The resulting confusion suggests such an account is simply not feasible. Nature will not be so easily defined, it seems.