Few have done more to tease out the fundamental mysteries of the universe than Dr. Gerard 't Hooft of the Institute for Theoretical Physics at Utrecht University in the Netherlands. For the last century, as physicists pried further into the atom to better understand this basic building block of the universe, they attempted to fit all they learned into the existing Standard Model Theory of particle physics. By the 1970s, so many conflicting adjustments had been made to the original theory that its very foundation had come into serious question. To resolve some of these conflicts, 't Hooft and his mentor, Martinus J.G. Veltman, applied newly developed computer technology; their calculations have enabled science to predict the behavior and properties of subatomic particles more accurately. They were awarded the 1999 Nobel Prize in Physics for placing the Standard Model Theory "on a firmer mathematical foundation." Ultimately, 't Hooft's work has brought physics closer to the development of a Unified Field Theory, which would provide a single framework for understanding all the forces of nature. In this podcast, recorded at the 2000 International Achievement Summit in London, England, Dr. 't Hooft traces his interest in science to his early childhood. In secondary school, he was already attending a professor uncle's lectures at the university. He shares some of his thought on theoretical physics and particle theory.