William J. Mullin is Professor Emeritus at the University of Massachusetts. His areas of research are quantum fluids and solids and low temperature physics. Most recently, his research has focused on Bose—Einstein condensation and the fundamentals of quantum mechanics. Mullin has authored 100 journal publications and 3 books and has been a visiting scientist for extended periods at the University of Sussex, Royal Holloway, University of London, and the École normale supérieure, Paris.