Applied Physics/Physics Colloquium: Charles Bennett- "Can we reason about our place in the universe without defining “us”, or Which of Occam's Razors should Wigner use to shave his quantum Friend?"

Abstract: Modern cosmology has revived interest in some early 20th century puzzles that had seemed to be more philosophical than scientific, the problems of Boltzmann’s brain and Wigner's friend.  The inability of a complete understanding of a physical system’s state and dynamics to reveal whether it is conscious plagues both ethics (“Which systems have rights?”) and cosmology (“What grounds do we have for believing that we are inhabitants of a young live universe rather than fluctuations in an old dead one?).  By universalizing Occam’s razor algorithmic information theory offers a way forward without defining consciousness or counting observers.

Charles H. Bennett is a physicist and information theorist at IBM's Research Division, known for his work on the physics of information, including the Maxwell’s demon problem, the thermodynamics of computation and error correction, and, with many colleagues, helping rebuild Turing’s and Shannon’s  theories of computation and communication on a quantum foundation, enlarging their scope to include quantum cryptography and computing, the quantitative theory of entanglement,  quantum teleportation, and the quantum reverse Shannon theorem.  More recently he became interested in the application of quantum information and computational complexity theory to cosmology, including the role of thermodynamic disequilibrium in the emergence of classical phenomenology and computationally deep classical structures from underlying quantum laws.  He has lectured worldwide to lay audiences, believing non-scientists can benefit from understanding the gist of quantum mechanics as well as they do, say, black holes.   His current interests include improving collaboration between natural and social scientists to understand and combat mis- and disinformation.  He is a Fellow of the American Physical Society, and a member of the National Academy of Sciences, and a recipient of the ICTP Dirac, Wolf, Shannon, and BBVA awards.