Filming seismograms and related materials at the California Institute of Technology

As part of a world-wide effort to create an international earthquake data bank, Caltech's seismology archive has been organized, labeled, described, and microfilmed. It includes a wide variety of original records, documents, and printed materials relating to local and distant earthquakes. At present, we are filming significant seismograms prior to 1963; more than 50,000 records written between 1924 and 1935 have been filmed to date. Seismograms are the principal source of information about earthquakes and the earth's interior. These records, housed at Kresge Laboratory, the headquarters for Caltech's seismological network of stations, are important because they span so much of the period for which instrumental data exists. The early history of the Laboratory points up the role technology has played in the advancement of the science

Viscosity, ion mobility, and the λ transition

A model is presented of the λ transition in superfluid helium in which fluctuations near the transition are approximated by distinct regions of normal fluid and superfluid. The macroscopic viscosity of such a medium is computed. The ion mobility is also computed, taking into account a region of normal fluid around the ion induced by electrostriction. The results are, for the viscosity, ηλ-η∼t^0.67 and for the mobility μ-μλ∼t^0.92 both in excellent agreement with recent experiments. The model suggests that the λ transition itself is the point at which superfluid regions become macroscopically connected

Control of ultralow pressures: an absolute thermodynamic manometer

A method of accurately manipulating the pressure of helium gas in the range P=10^–1 to 10^–20 Torr, T<5 K is presented. The method requires only a very modest apparatus and makes use of thermodynamic measurements on the 4He–Grafoil system. A calibration curve and a pressure scale for the manometer are developed which will allow convenient application in other laboratories. An experiment which utilizes the technique is briefly disscussed

A dynamic new look at the lambda transition

We discuss aspects of the theory of critical phenomena and explore the superfluid transition in 4He. We review some of the recent experimental and theoretical work on helium in nonequilibrium conditions and summarize some future space experiments that might shed light on disagreements between theory and experiment

“Now Boarding: The Flight from Physics” David Goodstein’s acceptance speech for the 1999 Oersted Medal presented by the American Association of Physics Teachers, 11 January 1999

All across the country, the number of students majoring in physics is said to be at its lowest point since Sputnik, 40 years ago. The most important role of the college physics course today seems to be to weed out a few poor souls who might otherwise make it to medical school or some other kind of quasi-scientific training. If the profession of teaching physics were a business, we would be filing for bankruptcy. On the other hand, our assets include nothing less than the wisdom of the ages, the most important part of the body of human knowledge. Mastery of that knowledge, a fundamental grasp of how the world works, ought to be the best possible preparation for the coming century. Rather than being an endangered species, the physics major should be the wave of the future, but it isn’t, at least not yet. This talk will analyze how we got ourselves into this fix, and suggest what is needed to get ourselves out of it

The origins of nuclear astrophysics at Caltech

Shortly before the start of World War II, several theoretical physicists, including Hans Bethe and Carl von Weizsacker, advanced the idea that the sun derives it energy from nuclear reactions within its core. C. C. Lauritsen and William Fowler, nuclear physicists at Caltech's Kellogg Laboratory, were among the first experimentalists to appreciate the application of nuclear physics to stellar interiors. Post-war strategies for studying nuclear processes in the stars included an innovative series of unofficial, weekly seminars with Mt. Wilson astronomers at director Ira Bowen's house, the testing of Bethe's carbon cycle in Kellogg, and the collaboration with a diverse group of scientists ranging from cosmologist Fred Hoyle to astronomers Margaret and Geoffrey Burbidge. The events leading up to the publication of the 1957 paper by Fowler, Hoyle, Burbidge, and Burbidge, in The Reviews of Modern Physics, now regarded as a watershed in the history of nuclear astrophysics, are discussed. For his work in low-energy nuclear astrophysics, Fowler won the 1983 Nobel Prize in physics

Theory and Observation of Displacement Phenomena in Coadsorbed Films

Displacement refers to a surprising phenomenon observed in a number of adsorption systems. At low temperatures, some relatively inert gases, such as krypton (Kr) or methane ( CH4), are found to displace molecules from preadsorbed monolayer films of a more condensable species, such as carbon tetrachloride ( CCl4), from a graphite substrate. We present a simple thermodynamic model to explain displacement and make a prediction applicable to both first-order and continuous displacement processes. We also present measurements on CH4/CCl4 and Kr/CCl4 coadsorbed films from 77–112 K that verify our prediction and yield the CCl4 film spreading pressure