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Mayda Velascoleft

‘Always something to discover’

A lifelong passion for physics drives Mayda Velasco to understand the mysteries of the beginning of the universe

By Rebecca Lindell

Decades after discovering her love for physics, Mayda Velasco still can’t contain her excitement for the field.

“We talk about how ‘we live in space.’ But it’s not space — it’s space-time, because the universe is in four dimensions,” Velasco says, emphasizing the point with an animated gesture. “If you are at the surface of the earth, you can talk about ‘space’ if you like. But if you want to describe things at the most fundamental level, it is space and time. Energy and momentum. Once I thought I understood this, by the way. Then you realize you don’t understand it — but it’s still cool!

“All these ideas one after the other, it’s like, wow!” Velasco exclaims. “All these things that are not supposed to be possible are actually possible — and there are explanations that are either known, or yet to be known. You just have to put together the pieces.

“Even after all this, it continues to be amazing. There’s never an end. There is always something!”

There is always something to discover, indeed — and that curiosity has driven Velasco not only to study the tiniest particles imaginable, but to assemble teams of international collaborators to help unravel the mysteries surrounding matter, antimatter and the beginnings of the universe.

Matter and antimatter

A professor of physics and astronomy at Weinberg College, Velasco is also director of the international COFI institute in San Juan, Puerto Rico — an organization she founded in 2014 to bring the best minds in Latin America and elsewhere to bear on issues in fundamental physics. She is also a fixture at CERN in Switzerland, where she works with the Large Hadron Collider to study the interactions of fundamental particles.

“The truth is there is something in common behind everything I do,” she says. “It is that I want to understand what happened to the antimatter.”

“Antimatter” — the material that drives Velasco’s curiosity — is composed, appropriately enough, of “antiparticles.” These have the same mass as particles of ordinary matter, but opposite charges and properties.

Matter and antimatter were in balance at the beginning of the universe, Velasco explains, interacting to produce light. But something happened to the antimatter in the moments after the universe was formed, because if there were an equivalent amount of matter and antimatter today, “we should just be a big ball of light,” Velasco says. “But obviously, we are not. So what happened? The truth is that we exist thanks to some sort of imperfection, and we don’t know what caused it.”

For the last several decades, Velasco has designed experiment after experiment to solve that question, one of the many smaller puzzles that comprise the larger mystery of the universe. She has worked to understand the “proton spin crisis,” the “electroweak sector,” and the decays of particles such as quarks and the newly discovered Higgs boson, which she had a hand in identifying.

For this work Velasco has gained international renown, earning fellowships from CERN and from the Sloan Foundation, as well as a Woodrow Wilson Award from the Mellon Foundation. She is an acknowledged leader in her field, serving on numerous international review committees and on boards for CERN and the United States government. UNESCO has even deemed Velasco the Chair on Fundamental and Interdisciplinary Physics at Northwestern University in recognition of her work to develop COFI, which has become an influential nexus for research in particle physics.

Velasco, in turn, brings that enthusiasm back to Northwestern, where she has taught, conducted research, and mentored dozens of undergraduates and graduate students since she joined the Northwestern faculty in 1999.

The accidental physicist

Velasco’s passion for particle physics is palpable and contagious. It’s also fortunate, considering that she hadn’t originally intended to pursue the field.   

As a child in Puerto Rico, Velasco grew up with abundant freedom to explore the natural world. At dinnertime, her family would gather around the table to listen to “lectures” by her father, a physician who had a particular interest in marine biology.

From a very early age, I was exposed to the ways that things are designed and planned, so for me it’s very natural to look for a mathematical explanation for things,” she says. “Or to discuss the probability that something is true or not. That is how I was brought up.”

Velasco had originally intended to follow her father into medicine. But the pre-med classes at the University of Puerto Rico were full when she went to register, so she signed up for math and physics classes instead. “And the more I studied them, the more I fell in love. It was so fun,” she emphasizes. “It was really, really fun for me.”

In physics and math, Velasco found explanations for things she had wondered about as a child To her delight, the answers just led to even bigger questions, ones she could spend the rest of her life pursuing.  

“We had played with magnets when we were little kids,” she recalls. “The first time I was told there was a particle that is being exchanged — a photon, which is physically the same particle as light —it was fantastic and amazing, but real! That’s the kind of thing that got me interested — seeing that things that are not supposed to happen in nature do happen.”

‘Trust your gut’

Velasco wants to ensure that girls aspiring to careers in science can experience that joy as well. For them, she offers a few tips borne of her own experience.

“Don’t get intimidated,” she advises. “In the beginning, for whatever reason, boys might seem to have the leading edge. But as you continue, you become better and better, and the gap that you perceived doesn’t matter anymore. It’s just a matter of patience. What you have to do is trust your gut.

“Because in the end, science is common sense,” Velasco says. “If you have an idea and you want to test it, be imaginative and take the risk. If it’s a good idea, the resources to pursue it will appear. And this is something that I have seen over and over throughout my career.”

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