The Cathedral Of Science

If physicists didn’t sound so smart, you’d swear they were making half this stuff up. The universe began with a big bang called, well, the Big Bang. It’s filled with wormholes and superstrings, dark matter and galactic bubbles, and assembled from little specks of stuff called fermions and leptons, top quarks and charm quarks, all of it glued together by, yes, gluons–and if you claim you understand a bit of it, you’re probably lying too.

That’s the trouble with particle physics: it exists on a plane that the brain doesn’t visit–or at least most brains don’t–and wholly defies our intuitive sense of order and reason, of cause and effect, of the very upness and downness of up and down. So we throw up our hands and turn it over to the scientists, and maybe every few years we read a Stephen Hawking book just to keep up appearances.

But when something really big happens, all that can change. As the Internet buzzed with the news that a wonderfully named God particle had been found, as the term Higgsteria was trending on Twitter, as scientists around the world opened champagne, the non–physics speaking joined in, high-fiving about a thing called a boson and cheering that the standard model had, in the nick of time, been saved. Now quick, what’s the standard model?

There was an odd and merry disconnect between how little most people truly understood the breaking news from the physics world and the celebratory reaction that nonetheless followed it. SALK VACCINE WORKS! we get. MAN LANDS ON MOON! we get. Understanding reports that a team of scientists working for the European Center for Nuclear Research (CERN) had proved the existence of a particle called the Higgs boson–physics’ white whale since it was first postulated in 1964–is a far harder hill to climb.

But the climb is worth it, for the discovery of the Higgs boson helps explain nothing less than why our existence is possible. The particle–named for Scottish physicist Peter Higgs, who was one of the small team of researchers who developed the idea–is the very reason any mass at all exists in the universe. Energy is easy. But energy and matter are like steam and ice, two different states of the same thing. If you can’t ping energetic particles with something–the Higgs boson, we’ve now proved–then planets, suns, galaxies, nebulae, moons, comets, dogs and people don’t exist. A cold and soulless cosmos may not care either way, but we very much do.

“We are nothing but quarks and electrons and a lot of empty space,” says physicist Fabiola Gianotti, who headed one of the two experimental teams at CERN that nailed down the discovery using the Large Hadron Collider (LHC), a $10 billion particle accelerator that crashes protons into one another at 99.9999991% of the speed of light. “People ask why it is so important to discover the particle that gives mass. But without mass, the universe would not be the way it is.”

Having the Higgs in hand is not the end of the work. The particle may help physicists crack some of the other great cosmological mysteries: the nature of gravity, the invisible dark matter that makes up 80% of the universe, the dark energy that is forever pulling the cosmos apart. There’s a strange mixing of faith and physics in all this–a contemplation of puzzles so hard to grasp and findings so consequential that they take on a sort of secular religiosity.

“My God!” Gianotti exclaimed, jumping up in her chair after she was brought the readouts proving that the Higgs had been found. Maybe it was just an exclamation, but the empiricist nonetheless took care to correct herself at the press conference later. “Thanks, nature!” she called out. But it was too late; the cat was out of the bag. She and her colleagues were grappling with something bigger than mere physics, something that defies the mathematical and brushes up–at least fleetingly–against the spiritual.

Keeping the Cosmos Sane

Despite its bland name, the standard model of particle physics describes some pretty elegant stuff. Completed in the 1970s after decades of work by physicists all over the world, the theory describes three of the great engines that run the universe: the weak nuclear force, the strong force and electromagnetism.

The weak force is carried by two particles–the W and Z bosons–and, as its name suggests, bonds matter loosely and over very short distances. Its tenuous grip on things is what leads to radioactive decay and, much more happily, initiates the hydrogen fusion that keeps the lights burning in stars like the sun. The strong force is a more robust thing: it causes protons and neutrons to come together in the nucleus of an atom. Carried by gluons, it is also the force that binds the quarks that make up protons. Electromagnetism is the force behind such phenomena as light and other everyday waves from radio to X-rays.

Neat, simple, almost intuitive. Except for one thing: all the particles at play in the model–except photons, which transmit light–have mass. And mass needs something to coax it into existence. Enter the Higgs boson. As Higgs and his collaborators explained things, the universe is filled with an energy field through which energetic particles must move the way an airplane has to push its way through a stiff headwind. Higgs bosons suffuse the field and are drawn to the particles; the more energetic particles attract more bosons, the less energetic ones attract fewer. This clustering gives the particles the solidity we associate with matter–and it does something else too. “The Higgs boson has two functions,” says Gianotti. “One is to give mass. The other is to prevent the standard model from going bananas.”

Bananas, in this case, means the standard model would fall apart. Avoiding that mess was a half-century job, but the pace picked up dramatically in the past two years thanks to work conducted by the LHC and the recently shuttered Tevatron collider outside Chicago. In both facilities, physicists didn’t study the proton collisions themselves so much as the quantum debris in the form of other particles that results from them. The goal was to find some that weigh in at 125 billion GeV (or electron volts), the mass predicted for the Higgs.

Lots of bumps appeared in the data at or around that target weight, but the Tevatron was never powerful enough to pin things down firmly, and the LHC, which went to work in 2008, has come online slowly over the years and did not achieve enough propulsive oomph to prove the Higgs case until 2011. Even then, it took trillions of proton crack-ups to produce enough readings to get to what physicists call the five-sigma level of certainty–and what everyone else calls the eureka moment.

That happened in late spring. Gianotti’s team and another led by Joe Incandela worked separately, and both turned their findings over exclusively to CERN research director Rolf Heuer. Thus, while the two team leaders knew that their own work was yielding positive results, only Heuer knew that they had both shot bull’s-eyes.

“When I saw the first plot from Joe and the first plot from Fabiola, I thought, O.K., we have it,” says Heuer. “When we all sat down together, I had to spell it out to them. They were reluctant to use the word discovery, but I persuaded them that yes, we can use it.”

The announcement of that discovery was made on July 4 to an exuberant crowd of physicists at the International Conference on High Energy Physics in Melbourne. A somewhat dazzled-looking Peter Higgs, now 83, was in attendance and received a long and warm ovation. “It’s an incredible thing,” he said, “that it happened in my lifetime.”

Through the Looking Glass

To fully fathom the implications of the find could take well beyond not only Higgs’ lifetime but also those of many other, much younger physicists. Particles produced in colliders last only a few trillionths of a second before decaying into smaller, more fundamental ones. If the Higgs just discovered is merely part of an extended Higgs family–a real possibility–each of those members will have its own particular decay channel and could lead down different research paths.

Take dark matter. Galaxies are large enough and spin fast enough that by rights they ought to fly apart. The fact that they don’t means the gravity from some unseen form of matter is holding them together. And in order to exert so much pull, it would have to be an awful lot of that matter–fully 80% of the universe. Most physicists believe that the invisible stuff is made of a particle of some kind. If that particle has mass, it’s interacting with the Higgs. Find the Higgs responsible and you may pull back the curtain on what the dark particles are.

Dark energy is a different matter–a force that pulls the universe apart rather than holds it together, contributing to the steady expansion that has gone on since the Big Bang. Part of the chatter after the Higgs was found was that it could help explain that too. No one remotely knows how–dark energy is a much newer concept than dark matter–but there will likely be a stampede to publish all the same. “Oh my dear,” says LHC and Caltech physicist Maria Spiropulu, “there will be approximately 2,000 papers next week connecting the Higgs to dark energy. Theorists are beasts like that.”

Gravity itself, the universe’s fourth great force and the one that is not addressed at all in the standard model, could also come in for some new understanding. One possibility is that gravitational attraction is also carried by a particle: a graviton. If so, one of the mysterious decay channels the Higgs travels may lead to its door too. All that, however, is for the years and the generations to come. And with the LHC still in its go-slow power-up mode and not even set to hit full throttle till the end of 2013, the hardware to do that work will only get better.

In the meantime, the rest of us can take a moment and reckon with what just happened. There will never be much return on investment–at least in the traditional sense–in the work at CERN. The field will spin out no Teflon or faster processors or global wireless service the way the space program did. But it is already paying other, far more valuable dividends. The boson found in the deep tunnels at CERN goes to the very essence of everything. And in a manner as primal as the particles themselves, we seemed to grasp that. Despite our fleeting attention span, we stopped for a moment to contemplate something far, far bigger than ourselves. And when that happened, faith and physics–which don’t often shake hands–shared an embrace.