Lisa Randall Brings Theoretical Physics To The Masses

This is part of our series on the Sexiest Scientists Alive.

It's refreshing to see one of the most highly-cited thinkers in theoretical physics being a good sport about topping our selection of the "Sexiest Scientists Alive."

"I'm old enough now to agree to this list!" Randall wrote in an email when we first approached her with the idea.

Part of the apprehension had to do with not wanting to be seen this way, preferring to focus on (and have others focus on) science.

So what changed her mind?

"Once you've achieved enough it's not worth worrying about," she told us. "When you're older, it's actually flattering."

Randall has certainly made waves both in school and in her field.

The New York-native didn't need the typical four years to complete her undergraduate work; she received her bachelor's in physics from Harvard University in just three, and immediately followed that up with a physics Ph.d from the same school.

She was the first tenured woman in the physics department at Princeton University and the first tenured woman physics theorist at MIT and Harvard, according to a Vogue profile.

After returning to Harvard as a professor in 2001, Randall wrote three books between 2006 and 2012, starting with "Warped Passages," and more recently, "Knocking on Heaven's Door," and "Higgs Discovery," all while managing an active research program.

In the past few years, she's appeared on Jon Stewart's "The Daily Show," ranked alongside Hillary Clinton and Steve Jobs in "Time" magazine's "100 most influential people in the world," and "Knocking on Heaven's Door" was named as one of "The New York Times"' 100 notable books of the year.

In summary: Lisa Randall is kind of a big deal. And she's got the good looks to go with it.

A star is born

Randall grew up in Queens, New York. She showed an early flair for math and science while attending Stuyvesant High School, an elite magnet school in Manhattan. It was the certitude of problem solving that drew Randall to physics, she tells Business Insider.

Interestingly, as a theoretical physicist, Randall's work is hardly grounded in definitive answers. It revolves around uncertainties, assumptions, and hypotheses that may not be provable within her lifetime — a seeming contradiction that Randall recognizes herself.

Randall studies the existence of extra dimensions in space, or those dimensions beyond the three spacial ones that we experience.

Her best-known theory, first published in 1999, attempts to answer one of the biggest unsolved mysteries in our understanding of the universe: Why is gravity — the force that binds all mass in the universe — so weak compared to the other fundamental forces in nature, like electromagnetism.

Speaking to "The New York Times" in 2005, Randall provided the example of how a small magnet can pick up a paper clip even though it's being pulled down by the entire Earth's gravitational force.

As a solution, Randall, along with Dr. Raman Sundrum, theorized that our universe exists within a higher dimension. Gravity is weaker in the three spatial dimensions that we perceive.

To test this theory, researchers used the world's most powerful particle smasher, located in Switzerland, called the Large Hadron Collider. The instrument, which recently shut down for long-term maintenance, shoots beams of protons in opposite directions through a 17-mile long circular tunnel. The collision essentially recreates conditions after the Big Bang (which created the universe) by producing a huge amount of energy that recondenses as new particles. One of those particles is a heavier partner of the graviton, the particle responsible for transmitting the force of gravity. If Randall's theory were correct than scientists would expect to see that heavier particle decay in the detector, and would be able to measure its property. While there there's still no definitive evidence of this, it remains part of the big story related to why particles have mass and why those masses are what they are.

The Higgs boson

Last July, experiments at the Large Hadron Collider revealed what appeared to be a Higgs boson, the long-sought subatomic particle that scientists think gives elementary particles mass, and would help explain how the universe came into existence in the first place.

The possible discovery was hailed as a historic scientific breakthrough, but the story is far from over, Randall points out.

"Physicists have yet to understand why the Higgs boson's mass is what it is," she explains. "Quantum mechanics would have you think it was sixteen orders of magnitude heavier. Without something more, only a fudge or "fine-tuning" would yield the correct result. It's a challenging problem and the answers could yield some deep insight into the nature of matter or even space."

The trouble with theory

For anyone seeking instant gratification, both experiments demonstrate the drawbacks of Randall's profession.

One of the biggest challenges is "continuing to pursue ideas, even when we know they might not be tested for a while," she acknowledges.

Her persistence comes from knowing that breakthroughs happen, even if they're long off: "You learn that the interest is in what you don't yet know and that theories evolve. But we nonetheless have progress and improved knowledge over time.

The future

In the next decade, Randall, who is currently single, still sees herself working and teaching students.

When she's not buckled down to her work, Randall stays active by climbing, skiing or biking.

Her prediction for the future, like the nature of her work, contains a dose of uncertainty coupled with the anticipation of new discoveries: "I don't know what will be my chief research focus and I don't know what other activities I might participate in. But it will be interesting to find out."