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What is time? Isaac Newton described it as absolute, but Einstein proved that time is relative, and, shockingly, that time and space are intricately interwoven. Now recent work in string theory and quantum gravity suggests that space and time may not be fundamental. If this is true, what new picture of reality will emerge?

Jim HoltAuthor

Jim Holt writes about math, science, and philosophy for The New York Times, The New Yorker, The Wall Street Journal, and The New York Review of Books. His book Why Does the World Exist?: An Existential Detective Story was an international bestseller.

Read MoreVijay BalasubramanianPhysicist

As a theoretical physicist at the University of Pennsylvania, Vijay Balasubramanian pursues research in two different fields: string theory and theoretical neuroscience. He is an expert in statistical inference and “Occam’s Razor”—the trade-off between simple and accurate mathematical models.

Read MoreCarlo RovelliTheoretical Physicist

Carlo Rovelli is a theoretical physicist and co-founder of the loop approach to quantum gravity. His main interest is the physics of space and time. Rovelli has also worked on the history and philosophy of science. His technical books include Quantum Gravity and Covariant Loop Quantum Gravity.

Read MoreLee SmolinTheoretical Physicist

Lee Smolin is a theoretical physicist who has made important contributions to the search for quantum gravity. Smolin is a founding faculty member at Perimeter Institute for Theoretical Physics. His five books explore philosophical issues raised by contemporary physics and cosmology.

Read MoreDavid Z. AlbertPhysicist, Philosopher

David Albert is the Frederick E. Woodbridge Professor of Philosophy at Columbia University and a physicist who explores quantum mechanics. He is world-renowned for his insights into philosophical questions about the nature of time, space, and other problems of modern physics.

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