Tara Shears spent the first 15 minutes of her hourlong Nobel Conference talk outlining our modern understanding of particle physics: 12 types of particles, four forces and an explanation for how they work together.
“The very fact that I’ve spent such a small fraction of my talk on what we understand should tell you that the entire universe is up for grabs when it comes to understanding it,” she said.
It was a happy dilemma, too, for the audience, considering that the mysteries of physics — like antimatter, dark energy and dark matter — capture the public imagination more than the quarks and leptons of the standard model.
Many of those mysteries are being studied at Shears’ workplace, the Large Hadron Collider near Geneva, Switzerland. Shears, also a physics professor at the University of Liverpool, was the second speaker at Gustavus Adolphus College’s 49th annual Nobel Conference. The conference, called “The Universe at Its Limits,” began Tuesday and continues today.
The conference’s title refers both to the tiniest bits of matter and the far reaches of the universe. Shears reinforced that link early.
As it smashes protons together at nearly the speed of light to see what comes out, the Large Hadron Collider is also investigating the primordial universe.
“It tells us what matter is made of at the very tiny scales, but also what the universe was doing in its first seconds of existence,” she said.
The collider is a 16-mile ring about 110 yards under the ground. Inside, a long chain of blue magnets keeps two streams of protons bent in circular paths. There are 40 million collisions a second, each one a re-creation of the conditions of the early universe. The collider has been working since 2010 and has reached about 8 teraelectronvolts, a unit of energy, about half of its design capability.