Everything we know about science says that physics should work just as well backwards as forwards, so why is it that time always moves forward? Why is it so easy to scramble an egg but impossible to unscramble it?

Nobel Laureate Anthony J. Leggett will give a public talk titled "Why Can't Time Run Backwards?" As part of the 2008 Montroll Lectures in Physics, Leggett will discuss one of the greatest conundrums of physics—why does time have a "direction?"

"We all feel that we can remember the past and affect the future, not vice versa, so there is a very clear arrow of time built into our interpretation of our everyday experience," says Leggett. "Yet, the fundamental microscopic laws of physics, be they classical or quantum-mechanical, look exactly the same if the direction of time is reversed."

Leggett is the John D. and Catherine T. MacArthur Chair and Center for Advanced Study Professor of Physics at the University of Illinois at Urbana-Champaign. He is widely recognized as a world leader in the theory of low-temperature physics, and his pioneering work on superfluidity was recognized by the 2003 Nobel Prize in Physics.

He is a member of the National Academy of Sciences, the American Philosophical Society, the American Academy of Arts and Sciences, the Russian Academy of Sciences, and is a Fellow of the Royal Society, the American Physical Society, and American Institute of Physics, and Life Fellow of the Institute of Physics. Leggett is also an Honorary Fellow of the Institute of Physics. He was knighted (KBE) by Queen Elizabeth II in 2004 "for services to physics."

In 2007 Leggett accepted a position at the University of Waterloo. For the next five years, he will spend at least two months a year on campus at the Institute for Quantum Computing in Waterloo.

The Montroll Lectures, named after the late Elliott Montroll, formerly the Einstein Professor of Theoretical Physics at the University of Rochester, is an endowed lecture series in the department of Physics and Astronomy that has brought high profile speakers to campus for the last 20 years.