Connecting the Fundamental Laws of Physics to Our Observable World

Cosmological theories move us closer to explaining the origin of the universe

The universe we see around us exhibits mind-boggling complexity, but operates on the basis of very simple underlying rules. Discovering what these rules are, and how they work together to create the rich environment of the world we observe, are some of the deepest questions in all of science. Dr. Sean Carroll, of the California Institute of Technology, is a theoretical physicist who asks profound questions about the universe and our place within it. His research is knowledge-based and curiosity-inspired, as he works to answer foundational challenges such as: Where did the universe come from? What are the underlying laws of physics? and How do complex structures arise from simple rules? Dr. Carroll's research is making enormous, breathtaking progress in addressing these ancient questions.

Collaboration with other researchers, graduate students, and postdoctoral researchers is crucial to Dr. Carroll's research. These collaborations help to make greater strides towards answering difficult questions and bring in people with different kinds of expertise to contribute to the interdisciplinary fertilization of ideas. In addition to his highly collaborative work, Dr. Carroll's work is unique because he takes a big picture point of view that answers questions about the universe in the broadest possible terms. He is pioneering an interdisciplinary approach that brings together ideas from particle physics, cosmology, gravitation, quantum mechanics, statistical mechanics, and the theory of complexity.

Current research includes: 

  • Emergence and Complexity: According to the Second Law of Thermodynamics, the universe grows more disorderly over time; nevertheless, complex structures such as galaxies and people come into existence. Dr. Carroll is proposing new frameworks for understanding the relationship between macroscopic complexity and microscopic disorder, as well as working to understand how the classical world emerges from the rules of quantum mechanics. These issues connect physics to information theory, biology, and even consciousness.

  • Cosmology, Particle Physics, and Gravitation: Dr. Carroll has pioneered new ways of understanding the dark matter and dark energy that dominate our universe, as well as the origin of the Big Bang and how it determines the arrow of time that distinguishes past from future. He and his collaborators are working to understand the largest components that make the universe what it is, and whether our universe is unique.

  • Understanding the Quantum Nature of Reality: Quantum mechanics is our most comprehensive and successful way of understanding reality, but even after decades of effort we still don't understand quantum mechanics itself. Dr. Carroll has developed a new approach to understanding how probability arises in quantum mechanics, and is investigating the foundations of quantum theory to better understand the emergence of spacetime, the nature of locality, and the appearance of multiple worlds.


Dr. Carroll is a theoretical physicist at California Institute of Technology (Caltech) in Pasadena, California. He does research on theoretical aspects of cosmology, field theory, gravitation, and quantum mechanics. He wants to learn about fundamental physics by studying the structure and evolution of the universe. These days he is especially interested in the arrow of time, the emergence and evolution of complexity, and how quantum mechanics intersects with cosmology. Dr. Carroll has done work on dark matter and dark energy, modified gravity, inflationary cosmology, extra dimensions, and violations of fundamental symmetries.

Dr. Carroll has written a couple of popular-level books: From Eternity to Here: The Quest for the Ultimate Theory of Time, and The Particle at the End of the Universe: How the Hunt for the Higgs Boson Leads Us to the Edge of a New World. He also wrote a graduate textbook, Spacetime and Geometry: An Introduction to General Relativity, and recorded lectures for the Teaching Company on Dark Matter and Dark Energy and the Mysteries of Time. He gives frequent public talks, and has appeared on TV shows such as Through the Wormhole with Morgan Freeman and The Colbert Report.

Dr. Carroll became interested in science when he was very young. He read books in his local library, poring through everything he could get his hands on about black holes, quarks, and the Big Bang. His interests inspired him to want to tackle the big questions about our universe -- where it came from, what it's made of, how it operates. Now he is fortunate enough to be doing exactly that. In his free time, Dr. Carroll enjoys playing poker and also consults for movies. Recent consultations include the films Thor: The Dark World and Big Hero 6, and the TV showsBones and Fringe



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Spontaneous Inflation and the Origin of the Arrow of Time



Andrew Gemant Award American Institute of Physics, 2014

Royal Society Winton Prize for Science Books, 2013

American Physical Society Fellow, 2010

Villanova University Alumni Medallion, 2006

Packard Foundation Fellow, 2005