There were two Nobel prize winners among the faculty in the physics department at the University of Texas at Austin when I was attending classes, seminars and colloquia there during the landmark years 1987 through 1999.
One of them was Steven Weinberg, whom UT-Austin managed to recruit from Harvard in 1980, just after Weinberg, Salam, and Glashow won the 1979 physics Nobel for their theory unifying the weak nuclear force with the electromagnetic force. That theory goes by the name electro-weak, although now maybe the name should be electro-weak-strong, since the strong nuclear force has also been subsumed under the same field theoretical tent, leaving only our dear friend (or enemy if you fall down and get hurt) the gravitational field of force unaccounted for by quantum field theory.
The other Nobel winner who resided in the physics department at UT-Austin during my years there was Ilya Prigogine, or Uncle Ilya as my friend Tom Mellet liked to call him. There's some controversy about the value of Prigogine's contributions, as described in one opinionated biographical sketch, but I think he was onto something in his attempts to look at quantum theory and chaotic systems in new and often philosophically interesting ways. In contrast, I see nothing philosophically interesting in the mathematical tour de force that is quantum field theory.
Weinberg is still living and still at UT-Austin. Prigogine actually divided his time between the Free University of Brussels and UT-Austin, and died in Brussels in 2003, aged 86. He was also director (appointed in 1959) of the International Solvay Institute, and it was due to his presence at UT-Austin that original black & white photos from the famous early Solvay Conferences (some with participants signatures on them) were displayed outside the large ground floor lecture hall in the Physics-Math-Astronomy building (R. L. Moore Hall). I once went by Prigogine's office to see if he had a copy of a book about the Solvay Conferences that I'd been unable to find elsewhere. He wasn't there, but his secretary (first name Amy is all I remember) found the book and loaned it to me without asking who I was or when I'd return it.
Prigogine's Nobel prize was in chemistry, awarded in 1977 for his "definition of dissipative structures and their role in thermodynamic systems far from equilibrium," as the Wikipedia article about him says. I have a partial paperback copy (and just ordered a full hardback copy) of his 1980 book From Being to Becoming, and offer a quote from it now concering a subject I've discussed here before, the difference in pure states and mixed states in quantum mechanics:
One of them was Steven Weinberg, whom UT-Austin managed to recruit from Harvard in 1980, just after Weinberg, Salam, and Glashow won the 1979 physics Nobel for their theory unifying the weak nuclear force with the electromagnetic force. That theory goes by the name electro-weak, although now maybe the name should be electro-weak-strong, since the strong nuclear force has also been subsumed under the same field theoretical tent, leaving only our dear friend (or enemy if you fall down and get hurt) the gravitational field of force unaccounted for by quantum field theory.
The other Nobel winner who resided in the physics department at UT-Austin during my years there was Ilya Prigogine, or Uncle Ilya as my friend Tom Mellet liked to call him. There's some controversy about the value of Prigogine's contributions, as described in one opinionated biographical sketch, but I think he was onto something in his attempts to look at quantum theory and chaotic systems in new and often philosophically interesting ways. In contrast, I see nothing philosophically interesting in the mathematical tour de force that is quantum field theory.
Weinberg is still living and still at UT-Austin. Prigogine actually divided his time between the Free University of Brussels and UT-Austin, and died in Brussels in 2003, aged 86. He was also director (appointed in 1959) of the International Solvay Institute, and it was due to his presence at UT-Austin that original black & white photos from the famous early Solvay Conferences (some with participants signatures on them) were displayed outside the large ground floor lecture hall in the Physics-Math-Astronomy building (R. L. Moore Hall). I once went by Prigogine's office to see if he had a copy of a book about the Solvay Conferences that I'd been unable to find elsewhere. He wasn't there, but his secretary (first name Amy is all I remember) found the book and loaned it to me without asking who I was or when I'd return it.
Prigogine's Nobel prize was in chemistry, awarded in 1977 for his "definition of dissipative structures and their role in thermodynamic systems far from equilibrium," as the Wikipedia article about him says. I have a partial paperback copy (and just ordered a full hardback copy) of his 1980 book From Being to Becoming, and offer a quote from it now concering a subject I've discussed here before, the difference in pure states and mixed states in quantum mechanics:
As noted in Chapter 3, a fundamental distinction is made in quantum mechanics between pure states (wave functions) and mixtures represented by density matrices. Pure states occupy a privileged position in quantum mechanics, somewhat analogous to orbits in classical mechanics. As indicated by the Schrodinger equation (see equations 3.17 and 3.18), pure states are transformed into other pure states during the time evolution. Moreover, observables are defined as Hermitian operators mapping vectors of the Hilbert space into itself. These operators also preserve pure states. The basic laws of quantum mechanics can thus be formulated without ever invoking the density-matrix description of states corresponding to mixtures. The use of that description is considered to be only a matter of practical convenience or approximation. The situation is similar to that considered in classical dynamics in which the basic element corresponding to the pure state is the orbit or the trajectory of a dynamical system (see, in particular, Chapters 2 and 7).In Chapter 3, the question was asked: Is quantum mechanics complete? We have seen that one of the reasons for asking this question in spite of the striking successes of quantum mechanics in the past fifty years is the difficulty of incorporating the measurement process (see the section titled The Measurement Problem in Chapter 3). We have seen that the measurement process transforms a pure state into a mixture and therefore cannot be described by the Schrodinger equation, which transforms a pure state into another pure state.In spite of much discussion (see the beautiful account by d'Espagnat'), this problem is far from being solved. According to d'Espagnat (p. 161), "The problem [of measurement] is considered as non-existent or trivial by an impressive body of theoretical physicists and as presenting almost insurmountable difficulties by a somewhat lesser but steadily growing number of their colleagues."I do not wish to take a position that is too strong in this controversy, because, for the present purpose, the measurement process is simply an illustration of the problem of irreversibility in quantum mechanics.Whatever the position one takes, the fundamental distinction between pure states and mixtures and the privileged position of the pure states in the theory must be given up. Thus, the problem is to provide a fundamental justification for this loss of distinction. It is a remarkable fact that the introduction of the entropy operator M (see the section on irreversibility and the formalism of classical and quantum mechanics in Chapter 8) as a fundamental object of the theory entails just this loss of distinction betWeen pure states and mixtures.
