In the “Research Matters” series, we visit labs across campus to hear directly from Stanford scientists about what they’re working on, how it could advance human health and well-being, and why universities are critical players in the nation’s innovation ecosystem. The following are the researchers’ own words, edited and condensed for clarity.
If you take that question that kids always ask – “But why? Why is it like that? Why does that happen?” – and just keep asking it, you might end up studying particle physics. Particle physicists try to describe you, me, and the universe in terms of indivisible particles and forces.
But, even with our most sophisticated theories of physics, we can only describe 5% of the universe. The rest is a mystery and dark matter is a major part of that unknown. We have abundant evidence for dark matter from cosmology and astrophysics. We suspect that it’s made of particles – because everything else is – but we don't yet have a candidate particle for dark matter.
I use particle accelerators to study the fundamental structure of matter. Right now, I’m using several accelerators to try to produce dark matter in the lab.
At the Large Hadron Collider at CERN in Switzerland, we’re colliding protons at the highest energies ever achieved by humans on Earth. And we’re looking for, essentially, weird stuff. That includes collisions where a large fraction of the product appears to be “missing.” What’s “missing” might be evidence for dark matter. We’re also hoping to build an experiment at SLAC where an electron beam hits a thin target; if electrons go in and almost nothing comes out, that too could be evidence of dark matter.
We work with large groups of people to solve these problems. The ATLAS experiment I work on at CERN involves more than 3,000 scientists – and yes, it really does take that many people. It’s an audacious human endeavor. And it’s amazing that you can get people from all over the world to agree that understanding our place in the universe and how we’re put together is valuable.
But it’s a really fraught moment for our science. I have fear for the work that I do at CERN, for example, because it relies heavily on the U.S. as a partner and there is talk about the U.S. pulling back from international cooperation. People are also worried about their ability to do their science and be their whole self. Some feel they have to choose between speaking their mind and funding their research.
I think there’s a perception that funding for basic science is just available for researchers to use, but it’s not. It’s highly competitive. You have to convince “investors” to give you resources, and you'll need to execute the plan that you’ve asked them to fund. For the kind of physics we do, the only investor who will assign value to understanding the fundamental structure of the universe is the federal government.
Throughout every stage of my career, the federal government has made it possible. I had a National Science Foundation graduate fellowship. I was a Fulbright Scholar, which is funded by the U.S. State Department. Almost everything I do is funded by the National Science Foundation and the Department of Energy.
Now, I worry about how I’ll secure funding for my students to make it possible for them to graduate in a timely way. I’m thankful Stanford guarantees a baseline of support for the students but you need other resources, too.
“This is trying to understand: What are we made out of? What is our universe made out of?”
In the 20th century, we revolutionized our understanding of the structure of matter and the structure of space time, through Einstein and the theory of relativity, and through the development of quantum mechanics. With particle physics, we are at a point where we have the most accurate model of nature that we’ve ever had but it, glaringly, cannot explain certain things such as dark matter or the abundance of matter over antimatter. The early universe was created in equal parts of matter and antimatter; they should have annihilated each other and we shouldn’t exist. But there’s some difference between matter and antimatter, and we don’t know what it is. And we know there is five times more dark matter out there than ordinary matter, but we don’t know what it is either.
It’s very possible that we will have some sort of paradigm-shifting discovery that addresses these questions in the next 50 years, because there’s so much that we don’t know.
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Lauren Tompkins is an associate professor of physics in the Stanford School of Humanities and Sciences.
Photographer
Andrew Brodhead
