Mar 4 2014
If you aren't a physicist, you might not have encountered the Berry phase, a property of waves in quantum mechanics. But perhaps you've heard of the levitating frog, a demonstration of an amphibian suspended in midair by a powerful magnet that captured the attention of scientists and nonscientists alike in 2000.
Both can be understood – at least in part – thanks to Sir Michael Berry, a renowned theoretical physicist who is visiting Stanford this week for the Robert Hofstadter Memorial Lectures, an annual lecture series in honor of the late Stanford physics Professor Robert Hofstadter.
"He's one of the famous theoretical physicists," said Leonard Susskind, professor of physics at Stanford, who helped select Berry to serve as the 2014 lecturer. "He's a very good speaker and somebody whose work I have admired for many years."
Berry, an emeritus physics professor at the University of Bristol, specializes in the "border between physics and mathematics" and is known for his work on geometric phases and optics. Unlike his fellow physicists who specialize in nanoparticles, black holes and string theory, Berry said he prefers "corners that are not fashionable."
"I like to find new things in old things," Berry said.
For example, Berry said he is currently having fun analyzing a phenomenon known as the squinting moon, an angular illusion that appears when the sun and the moon are both visible. And he counts the cracking of a 150-year-old mathematical puzzle as one of his most prized accomplishments.
As a youth in England, Berry was fascinated by astronomy. Once at Exeter University, he discovered the beauty of physics and mathematics and has pursued both ever since.
Well-known in the science community, Berry's work attracted media attention in 2000, when he and colleague Andre Geim, a physicist at the University of Nijmegen in the Netherlands, won the Ig Nobel prize for explaining why a powerful magnet can be used to levitate a non-magnetic object such as a frog. The Ig Nobel prizes are awarded each year to recognize scientific work that prompts laughter, as well as thought. Though some scientists shun the silly ceremony, Berry said he urged Geim to accept the honor – the prize celebrates, rather than ridicules, science, and prompts public inquiry, he said.
After the frog video went viral, Berry said he was often asked whether humans, too, could float. The answer, he said, is not yet, because current magnetic fields can't be created over a large enough volume. In addition, the real trick is not just cancelling gravity but getting such a weakly magnetic object to be suspended stably. But the decorated physicist declared his eagerness to volunteer, although the experience would feel quite strange: the magnets would tug more strongly on bones rather than flesh, causing them to separate, slightly.
Berry's first lecture will be held Monday evening, March 3, and is intended for a general audience. He plans to connect abstract mathematical and physical concepts to easily observable natural phenomena in a presentation for the science-curious public. The "Seven Wonders of Physics" begins at 8 p.m. in the Hewlett Teaching Center, 370 Serra Mall, Room 200.
Berry will present a more technical colloquium Tuesday afternoon entitled "Hamilton's Diabolical Singularity," which addresses the initial 1831 application of phase-space theory, a concept that remains relevant in modern physical thought. It begins at 4:15 p.m., March 4, in the Hewlett Teaching Center, 370 Serra Mall, Room 201.
Both events are free and open to the public.
The Hofstadter Lectures commemorate the late Nobel Prize-winning physicist Robert Hofstadter, who was a member of the Stanford faculty from 1950 until his death in 1990. Eminent speakers are invited each year to give lectures on the subjects of physics and the physics of medicine.
Becky Bach is an intern at the Stanford News Service.