Crisis in Physics Spurs Spirited Dialogue

Abstract

Although Sidney Nagel’s Opinion piece (Physics Today, September 2002, page 55) was interesting and thought-provoking, I disagree with some of the points he made. US physics may be in crisis because of the rather poor funding support that it has received in recent years, but not for the reasons Nagel suggests.Let me list some points of disagreement: ▸ “Great discoveries [in particle physics] are less frequent,” Nagel says. Actually, the past few years have seen remarkable advances: the detection of oscillations of atmospheric neutrinos, the solution of the solar neutrino problem, the establishment of charge conjugation–parity violation in the B system, and affirmation of the standard model at CERN’s Large Electron–Positron Collider and at Fermilab.▸ The notion that “we do not really appreciate what is done in other areas” may be true of some physicists, but many faithfully attend weekly physics colloquia that cover every subfield. Because physics knowledge has expanded so much in recent years, it is more difficult to remain well informed even within one’s own field, but that knowledge explosion is, in my opinion, a good thing, not a crisis.▸ Nagel says that “small physics … has gotten even smaller.” I think some areas that used to be small physics have actually gotten bigger rather than smaller. For example, many condensed matter physicists now use synchrotron light or neutron sources and sophisticated beam lines, devices that require substantial teams to build and operate. In my opinion, most of experimental physics has gotten bigger.▸ “To study … condensed matter physics, … does one need to know the standard model?” Nagel rightly answers, “Of course not.” On the other hand, some older reductionist results, like the fact that atoms are made of nuclei and electrons, do seem useful. Note that the tools of particle physics (like particle accelerators) may be useful to areas such as condensed matter physics. I cannot believe that a condensed matter or plasma physicist would not marvel at the beauty of the standard model and the intellectual accomplishment it represents, even if it had no impact on his or her own work.▸ Nagel also mentions “the growing split between theory and experiment in all areas of physics.” It is my impression that theory and experiment have been working very well together in many areas. I just read a piece about recent theoretical work done to explain experimental observations on the new superconductor MgB2. The combination of theory and experiment that led us to our present understanding of solar neutrino astrophysics is extraordinary. Despite these disagreements, I fully agree that closer interaction between the practitioners of various areas of physics is desirable. James Langer, former president of the American Physical Society, had urged that the March meeting be an example to other APS divisions to meet together to allow improved cross-fertilization and give young people the opportunity to see many different subfields. My division, particles and fields, has decided to hold every second divisional meeting within the APS April meeting, starting with the 2003 gathering in Philadelphia.The real crisis arises from the inadequate funding of the physical sciences. In arguing for improved funding, we physicists should push for all of science and, within that, for all active areas of physics. I strongly agree that, in our talks, we ought to always explain why others in different fields should care about what we are doing.© 2003 American Institute of Physics.