Dear colleagues, Next Monday's Physics colloquium may be of interest to many of you. See below. Best wishes, -Martin ---------- Forwarded message ---------- From: Maynard, Dayle <maynard(a)fas.harvard.edu> Date: Tue, Mar 17, 2015 at 5:06 PM Subject: Announcement for Harvard Physics Colloquium Speaker Wojciech Zurek, Los Alamos, NM on 03/23/15 Harvard Physics Colloquium Monday, March 23, 2015 4:15 p.m.-5:15 p.m. in Jefferson 250 Tea served in Jefferson 450 @ 3:30 p.m. *“Decoherence and Quantum Theory of the Classical.”* Wojciech Zurek Los Alamos, NM For announcement poster please go to: http://www.physics.harvard.edu/events/colloquium.pdf I will describe three insights into the transition from quantum to classical. After a brief discussion of decoherence I will give (i) a minimalist (and decoherence-free) derivation of preferred states. Such pointer states define events (e.g., measurement outcomes) without appealing to Born's rule. Probabilities and (ii) Born’s rule can be then derived from the symmetries of entangled quantum states. With probabilities at hand one can analyze information flows from the system to the environment in course of decoherence. They explain how (iii) robust “classical reality” arises from the quantum substrate by accounting for all the symptoms of objective existence of preferred pointer states of quantum systems through the redundancy of their records in the environment. Taken together, and in the right order, these three advances (i)-(iii) elucidate quantum origins of the classical. W. H. Zurek, Physics Today 10, 44-50 (2014).