The Quantum Experience - The Higgs boson explained (sort of)

Assistant Professor of Physics Nathaniel Cunningham takes a deep breath and tries not to grit his teeth when he reads most media descriptions of the recently discovered Higgs boson—the subatomic “God particle” announced on Independence Day at the Large Hadron Collider outside Geneva, Switzerland.

“Particle physicists everywhere cringe when they call it that,” Cunningham said. (So do theologians.) It’s easier to talk about what a Higgs boson isn’t than to pin down exactly what it is. For one, it’s not God. It’s not a particle, either—at least, not in the concrete sense. It doesn’t behave like a subatomic grain of sand.

Reality changes dramatically at the atomic level. (For instance, consider that the hydrogen and oxygen atoms in your glass of water are perfectly dry.) Understanding the Higgs field requires a similar step away from common reality. “The word ‘particle’ is an inadequate description of a Higgs boson,” Cunningham said. “So is ‘wave.’ A Higgs boson is more like a localized wiggle in a field.”

Okay… So what do these localized wiggles do?Illustration by Peter Worth / Local Hero

They lend the quality of mass to subatomic particles interacting with the field. Maybe you’ve seen the online videos. A red ball representing a quark (the building block for an atom’s protons and neutrons) is cruising along until it hits the Higgs field’s bluish ether. The quark starts to shimmy and quake as all these tiny electric-blue Higgs bosons blip into and out of existence, glomming onto the quark and putting on the brakes. As a result, a quark that would otherwise zip through space like light instead has mass and can cluster together to make cool things like atoms and molecules and water and planets and you.

Cunningham is okay with these videos. They help us visualize what’s happening subatomically. But it’s not quite accurate to think of Higgs bosons as the cosmos’s tiny brake pads. He said, “Those videos suggest friction,” as if the Higgs field were grinding these particles to a halt. “That’s not quite right. It’s about affecting inertia, not creating friction.”

The best metaphor Cunningham has heard for how the Higgs field works puts the quark in the role of celebrity and Higgs bosons in the role of paparazzi. “The paparazzi surround the celebrity and make it difficult for him to get moving,” Cunningham said. “Once he does, the paparazzi move, too. Now it’s hard for the celebrity to stop because they have this inertia.”

Cunningham said the discovery of the Higgs boson is significant because it validates the standard model of quantum mechanics. “We’ve known for many years that the Higgs field exists. It’s simply demanded by the mathematics of the standard model,” he said. Now that experimentation has revealed it, physicists have the last great piece of the puzzle of quantum mechanics’ picture of subatomic particles.

And while Cunningham may cringe at most media portrayals of this newest figure in particle physics, he empathizes with the science writer’s dilemma. “It’s hard to wrap words around what the math shows because the quantum experience is so different from the common experience.”

See an experimental physicist and cartoonist team up to explain the Higgs boson at vimeo.com/41038445.