Hamilton Colloquium Series: Anthony Leggett, University of Illinois, "Why I don't believe that Quantum Mechanics is the Whole Truth"

Not long after the birth of quantum mechanics nearly a century ago, Erwin Schroedinger pointed out, in his famous "Cat" paper, the difficulty which arises if we assume that the theory gives a complete account of the world up to and including our observations of it. This difficulty, known as the measurement, or better realization, problem, has generated thousands of papers in the literature which claim to have resolved it. In this talk I will first explain why I do not believe that any of these "solutions" is satisfactory, and secondly review the progress which has been made over the last two decades in setting constraints on a possible breakdown of the quantum description as we progress from the microscopic level to that of our everyday experience.