Fateful friendships may have played an important role in Philip Bucksbaum's career, but staying true to his interests in physics has been the key to his success. It was tagging along to a room-mate's physics class, during his first year as an undergraduate at Harvard, that triggered his interest in physics. The class, taught by Nobel laureate Edward Purcell, prompted Bucksbaum's most pivotal career decision: to become a physicist. “That class changed my whole view of things,” he says. (see CV)

Bucksbaum did his physics PhD at the University of California, Berkeley, where a lifelong friendship with Steven Chu — then a fellow graduate student, now director of the Lawrence Berkeley National Laboratory and Nobel prizewinner in physics — would influence his career. After realizing their common interests, Bucksbaum and Chu worked with others in Eugene Commins's lab to test the subtle effects of the electroweak forces at work in atoms.

Graduate research proved a tremendous experience for him. “In grad school somebody else finds the money and you get to devote all of your energy to your experiment,” he says. There are few other opportunities to concentrate so single-mindedly on a high-risk, high-payoff project, he adds.

After receiving an offer for a postdoctoral fellowship at the University of Oxford, UK, Bucksbaum gave a talk at Bell Labs in Murray Hill, New Jersey, where Chu had ended up. Bell Labs offered Bucksbaum a postdoc to pursue his interests in picosecond spectroscopy — he turned down Oxford and spent the next decade at Bell. During that time laser pulses became more than 1,000 times faster, drastically increasing the range of fast-moving physical phenomena that scientists can measure.

In 1990, Bucksbaum joined the University of Michigan, where he eventually became the director of the National Science Foundation's ultrafast science centre. He now directs the new Stanford Ultrafast Science Center, where one of the world's first X-ray free-electron lasers is now under construction. He says this technology will not only lead to a revolution in the ability to image small molecules and their motion, but will also have an impact outside physics in disciplines such as chemistry, biology and materials science.

Although key friendships have influenced Bucksbaum's career, he cautions young scientists to do the kind of science they want to do, not something they think they should do. “Have confidence in your own curiosity and be fearless about pursuing it,” he says.