As a science writer, one of the most useful prompts when speaking to a researcher about their work is to ask them to explain it to you as if you were a five-year-old. Luckily, professor David Leibrandt, a UCLA quantum physicist who recently won a $1.25 million Gordon and Betty Moore Foundation award, actually has a five-year-old daughter and has answered this question before.
“Think of my work like a game of telephone,” he says. “I have a question for a molecule but I can’t talk directly to a molecule. So, I talk to a laser and tell it what to ask. The laser talks to an atom and tells the atom what to ask. The atom then talks to a molecule and asks it a question. Then it goes back up the chain. If everything runs as planned, I have learned something new about how molecules behave at the quantum level.”
This may be a simple analogy, but the problem Leibrandt is trying to solve couldn’t be more complex. He is trying to fill in a missing piece from the laws of physics and, ultimately, answer the question of how our universe began and what it even is. To better understand his work, let’s take a step back.
Most people have heard the term “dark matter” before. Dark matter is all around us (and even flowing through us!) but we are unable to detect or observe it with any of our current instruments. How do we know it exists? Because we can observe its effects on other objects. Sitting inside on a windy day watching a tree blow, you’d be able to surmise that something is making the tree move. You can’t see it or feel it, but you know the wind is there. That’s how we experience dark matter.
In the past, Leibrandt built some of the most precise atomic clocks ever to help detect dark matter. In fact, one of his clocks was so precise that if it had started counting time at the beginning of the universe (14 billion years ago) it would be off by less than 1 second today.
This is important because the more precise our measurements are at the atomic level, the better we can compare them to the laws of physics as we currently know them to be. In most cases we can confirm what we already know. But in some cases – really special and mind boggling cases – we can demonstrate that our laws are incomplete. And that brings us to Leibrandt’s current work, his Moore Foundation award, and the question of “symmetry violation.”
According to our understanding of the universe, the Big Bang should have produced equal amounts of matter and antimatter in the universe. There are two problems with this. First, the universe is almost entirely matter. Second, when matter and antimatter meet, they destroy each other. If an equal amount of both were created, where is all the anti-matter now? And how are we, or the universe itself for that matter, even here if the two should have annihilated each other?
The only conclusion is that something is missing from the laws of physics.
“The support from the Moore Foundation is invaluable in helping us to find this symmetry violation,” said Leibrandt. “It will allow us to build novel tools and conduct a wide array of new experiments to help explain one of the biggest questions in physics today.”
Leibrandt plans to do this using the same precision measurement techniques he perfected working on atomic clocks. What that means for science, our understanding of the universe, and ultimately society, are unfathomable to us today. Consider the laws of gravity and relativity. With each new realization into how the universe works, humanity has built entirely new worlds.
Concretely, this might mean new tools and devices that can do things we never could have imagined before. But it goes much deeper than that. If history is a guide, a change in our understanding of the universe leads to entirely new ways of thinking about humanity, and even reality itself. This, in turn, leads to new ways of structuring the very societies we live in.
“Researchers like Professor Leibrandt are poised to make seminal contributions to our understanding of the universe.” remarked Theodore Hodapp, Program Director for the Experimental Physics Investigator program that funded David. “The Foundation and our reviewers were impressed with the thoughtful way in which he is constructing these extremely sensitive and consequential experiments.”
Leibrandt, who joined UCLA last year, is one of many new faculty in Physical Sciences and beyond who are helping to position the university as a leader in the quantum science that may one day bring about that new world.
“David’s search for symmetry breaking is particularly relevant for our understanding of one of the most basic aspects of chemistry and biology. Symmetry breaking extends from the smallest to the largest objects in the universe and David is poised to help us understand its origins,” said Miguel García-Garibay, dean of UCLA’s division of physical sciences.
For Leibrandt himself, the physics department at UCLA was the natural choice to continue this kind of work.
“This university has made a commitment to quantum research that can be seen both in the critical mass of research supported here and the quality of people doing the work,” he said. “Across several departments, and especially where I work in physics, the researchers at UCLA are especially creative, dynamic, and collaborative. I’m excited to be a part of this group.”