In Search of the God Particle

Article excerpt

Byline: Martin Rees

SCIENTISTS have spent decades looking for the elusive Higgs boson. They may have just gotten one step closer to finding it, and unlocking the mystery of how we all got here to begin with.

THE EXCITEMENT FROM Europe earlier this month was palpable. Experiments had hinted at the discovery of a new fundamental ingredient of nature--a particle called the Higgs boson. This wasn't just any particle, but one that could potentially tell us that the theory physicists have been using to understand matter's fundamental building blocks for the last half century is premised on a secure foundation.

Even nonscientists--those for whom terms like "Higgs field," "gigaelectronvolt," and "hadron" are almost a foreign language--were thrilled, inspired by the notion that we are on the verge of unraveling mysteries previously beyond our grasp.

"Hadron," in fact, refers to particles that interact through one of the four forces of nature known as the strong nuclear force. The Higgs-boson experiments are taking place at the Large Hadron Collider, an enormous particle accelerator crossing the French-Swiss border. In the LHC's underground labyrinth, scientists can observe the collision of protons--a type of hadron--that have been accelerated to nearly the speed of light. These protons collide a billion times a second in a tiny region smaller than a human hair. When they do, they can turn into energy, as predicted by Einstein's theory, and that energy can then create new types of matter, never before seen.

On the afternoon of Tuesday, Dec. 13, in Geneva, spokespeople from the two major LHC experiments, called ATLAS and CMS, announced the status of their respective searches for the Higgs boson. Named for the British physicist Peter Higgs, the particle--if it exists--would tell us that the Higgs mechanism, the half-century-old idea for understanding how elementary particles acquire their masses, is correct. Those masses are essential to much of the structure we see in the world. If electrons didn't have mass, atoms wouldn't form. And then neither would galaxies, planets, or life. There's a lot more to all this structure than the Higgs mechanism alone, so the name "God particle," coined by the Nobel Prize-winning physicist Leon Lederman and relished by the popular media, might be a bit misleading.

Nonetheless, the Higgs mechanism is critical to today's theory of the basic elements of matter. Higgs and his colleagues theorized that space itself contains a sort of charge. Elementary particles acquire mass through their interaction with the charge (you might think of this charge as a traffic camera that slows down traffic even without any actual policemen to stop the cars). Space isn't filled with Higgs-boson particles--you need a collider such as the LHC to make those--but the Higgs boson is the telltale sign that there really is such a "charge" in space.

But here's the catch: the Higgs mechanism hasn't yet been vindicated by experiments. The reason the news from Geneva was so momentous was that scientists at the LHC might have come one step closer to proving it. Such a discovery won't turn our world around tomorrow. But basic science is like that. For all the deep and fundamental truths we learn about nature, it's rarely clear right away what the implications will be. …