About this episode
J. Richard Gott discusses the theoretical physics of time travel and whether it's scientifically possible. Gott examines solutions to Einstein's equations that permit time travel including rotating universes and cosmic strings. The conversation explores the grandfather paradox and other logical problems time travel creates. Gott discusses the concept of closed timelike curves and the physics allowing travel to the past. The discussion addresses practical challenges of building a time machine including the energy requirements and exotic matter needed. Gott examines evidence from quantum mechanics suggesting time's nature differs from common intuition. The broadcast explores whether time travelers from the future might already be present in our era. Gott discusses the implications of time travel for causality, free will, and the nature of reality. The conversation addresses whether physics fundamentally forbids time travel or merely makes it extremely difficult. Gott examines what time travel would mean for history, determinism, and whether the future already exists. The discussion explores the cutting edge of theoretical physics investigating time's deepest mysteries.