a beautiful mind; Harvard physicist Lisa Randall has unlocked secrets of a hidden universe.

Byline: Robert Sullivan

On a glorious spring morning in Cambridge, Massachusetts, Harvard theoretical physicist Lisa Randall is walking fast, like an energized particle. "It's just that I have a meeting and I want to prepare," she apologizes as she leaves her Cambridge town house. "And I want to get a latte." It took a lot of lattes over the course of three years for Randall to write Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions, but the book, which The New York Times has called "mind-bending reading," has made her the theoretical physicist most likely to appear on Charlie Rose, as well as one of the most-cited scientists in her field. She was the first woman tenured in physics at Princeton, and the first woman theorist tenured in science at both Harvard and MIT; in naming her as one of the 100 most influential people of 2007, Time wrote, "A physicist jolts the boys' club by reshaping the universe." It would take a lot of time to understand the scientific mind behind the person now headed toward her coffee, but Randall's longtime friend Christina Buchmann, a writer and editor in Berkeley, credits her innate gift. "I read a line from Rikki-Tikki-Tavi, by Kipling, the other day," Buchmann said, "and I thought, That's a perfect description of Lisa. It says, 'It is the hardest thing in the world to frighten a mongoose, because he is eaten up from nose to tail with curiosity.' "

With her high cheekbones and quiet elegance, Randall, 45, is less apt to be mistaken for a mongoose than for an actress studying for the part of Harvard professor, but as she makes her way to the edge of campus she exhibits a quick acceleration-and a penchant for minute observation. On Boston traffic, whose mechanisms remain unexplained, she laments, "It's ridiculous. There's absolutely no signage." Which leads to another observation, on urban design. "You know, I just read Robert Caro's biography of Robert Moses," she says, veering sharply left into Starbucks. "I used to think my parents ruined my childhood, but it was Moses."

The childhood she refers to began in Fresh Meadows, Queens-a neighborhood bordered by the theoretical-sounding Utopia Parkway. "It was supposed to be the ideal place to raise kids," she says. "But where I grew up was a development, and all the houses look pretty much the same. There was an architectural critic who pointed out that they had different doorways, which I never noticed." In her high school years, she persuaded her mother to allow her to ride the subway each morning to Manhattan-to Stuyvesant High School, where she won a prestigious Westinghouse science prize and enjoyed working hard in all her subjects but fell in love with math and science. Next came Harvard, for undergraduate and graduate work; then Berkeley, M.I.T., and Princeton. Since 2001, she has been a professor at Harvard, where she is one of the few women in her field.

"It's difficult for women in science," says Randall, who is wearing a cool denim jacket, a black-and-blue pleated skirt, a blue T-shirt, and Donald J. Pliner sandals. "It's a double-edged sword. I don't want to seem frivolous-though obviously I'm not, because I'm a physicist." She is understandably reluctant to opine. "I think there are a lot of women in physics-and there really aren't that many women in physics-who sort of don't really know how they should dress," she says. "You want to just blend in. On the other hand, you're never going to blend in. The great thing about getting older is you don't have to care."

This morning's passersby might see a reserved professor when they pass Lisa Randall, but Raman Sundrum, a physics professor at Johns Hopkins, points to her intellectual audaciousness. "It was very exciting," he says of their work together on extra dimensions-physical places outside our immediate experience that, as far as the theory goes, may warp time and mass and distort the influence of gravity, a little like multiple mirrors in a dressing room. "It was quite an ...