Sean Carroll is a physicist and author. He received his Ph.D. from Harvard in 1993, and is now on the faculty at the California Institute of Technology. His research focuses on fundamental physics and cosmology, especially issues of dark matter, dark energy, and the origin of the universe. Carroll is the author of The Particle at the End of the Universe (2012), From Eternity to Here: The Quest for the Ultimate Theory of Time (2010), and Spacetime and Geometry: An Introduction to General Relativity (2003). He has written for Scientific American, New Scientist, and The Wall Street Journal. He frequently consults for film and television, and has been featured on television shows such as The Colbert Report, PBS's Nova, and Through the Wormhole with Morgan Freeman.