L. I. Schiff

On Experimental Tests of the General Theory of Relativity

This paper explores the extent to which the three “crucial tests” support the full structure of the general theory of relativity, and do not merely verify the equivalence principle and the special theory of relativity, which are well established by other experimental evidence. It is shown how the first-order changes in the periods of identically constructed clocks and the lengths of identically constructed measuring rods can be found without using general relativity, and how the red shift and the deflection of light can be computed from them. Only the planetary orbit precession provides a real test of general relativity. Terrestrial or satellite experiments that would go beyond supplying corroborative evidence for the equivalence principle and special relativity would be extremely difficult to perform, and would, for example, require a frequency standard with an accuracy somewhat better than one part in 1018.

Production of Particle Energies beyond 200 Mev

Six proposed devices for the production of charged particles with energies greater than 200 Mev are described briefly. These are: betatron, synchrotron, microtron, linear resonator accelerator, linear wave guide accelerator, and relativistic ion cyclotron. Attractive features and possible difficulties are discussed in each case. An Appendix presents some results of the theory of radiative energy loss by fast charged particles.

Theory of high-energy potential scattering

SummaryA new formulation for high-energy potential scattering, presented in a recent paper, is extended to provide explicit formulas for the scattering theory of the three-dimensional non-separable Schrödinger equation. An integral equation is derived, for which a single iteration gives the scattering when the potential energy is not too large and is slowlyvarying compared to a wavelength. The result agrees with those obtained earlier for small and for large scattering angles, but applies as well to intermediate angles and improves the earlier accuracy. Further iterations can provide greater accuracy as well as an error estimate for the first approximation.RiassuntoSi estende una nuova formulazione dello scattering per potenziali di alta energia presentata in un recente lavoro, per ricavare formole esplicite per la teoria dello scattering dell’equazione tridimensionale non, separabile di Schrödinger. Si deriva un’equazione integrale per la quale una sola iterazione dà lo scattering se l’energia potenziale non è troppo grande e varia lentamente rispetto a una lunghezza d’onda. Il risultato si accorda con quelli ottenuti precedentemente per angoli di scattering piccoli e grandi, ma si puÒ altrettanto bene applicare agli angoli medi e migliora la precedente esattezza. Ulteriori iterazioni possono dare maggior esattezza, come pure una stima dell’errore della prima approssimazione.

Statistical Analysis of the Counting Rate Meter

The counting rate meter, or vacuum tube speedometer, is an integrating and averaging instrument with an electrical, exponentially decaying memory. It is designed to replace message‐register equipment in all particle counting apparatus, and is ideally suited to continuous photographic recording. The average current to the output meter is proportional to the counting rate for constant sources or for decaying sources whose mean life is significantly greater than the time constant RC of the output tank circuit. This RC is analogous to a radioactive mean life and may be regarded as the mean memory time. While the output current depends only on the output resistance R, and not on the output capacitance C (except for very rapidly decaying sources), the statistical fluctuations in the output current depend upon RC, and are equivalent to the fluctuation expected in a time interval of 2RC. Expressions are derived for the condenser charge Q, or output current Q/RC, for constant and decaying sources of radiation, as ...

Čerenkov Radiation in a Dispersive Medium

Attention is called to the disagreement between a recent statement of Sommerfeld that the direction of propagation of Cerenkov radiation in a dispersive medium is determined by the group velocity, and the generally accepted result that the phase velocity must be used. The latter is shown to be correct, and the role of the group velocity is discussed in a way similar to that given in Tamms 1939 paper on the theory of the Cerenkov radiation.

Scattering of Waves and Particles by Inhomogeneous Regions

A review is given of the classification of several different kinds of wave motion that are of physical interest. Effects of the wave medium, nonlinearity, transformation properties, interaction between wave systems, and quantization, are discussed briefly. Examples are given of the analogy between electromagnetic and Schrodinger waves, and of the calculational methods used both in normal mode and in scattering problems.

Quark selection principle

Abstract A selection principle that permits only the observed combinations of quarks to exist as well-separated clusters, is formulated in terms of a boundary condition on the many-particle wave function. Calculated quantities are in reasonable agreement with experiment.

Lateral boundary mixing in a simple model of ocean convection

Abstract An approximate solution of the equations of thermal convective flow is obtained for a simple ocean model that incorporates lateral boundary mixing in an extreme form. It is found that the imposition of constant temperature along these boundaries causes the temperature to be nearly constant throughout the volume even though the top and bottom are maintained at different temperatures. As a consequences of this model, there is strong horizontal flow in thin layers close to the top and bottom; the thickness of these layers in a typical case is a few meters.

Felix Bloch: A brief professional biography

October 23, 1965, the sixtieth birthday of Felix Bloch, has marked an appropriate occasion for review of his accomplishments as one of the great physicists of this generation.

Thinking in quantum terms

It is now generally accepted that quantum mechanics occupies a central place in microscopic physical theory. The importance of this discipline shows up in the research journals, and also in the graduate physics curriculum. Not only is quantum mechanics a required subject, both for experimental and theoretical students; it appears as well to be influencing the way in which classical physics is taught. Presentations of classical mechanics that slight the traditional problems of planetary motion, unsymmetrical tops and dissipative systems in favor of collision theory and Poisson brackets are becoming more and more prevalent. With the much younger subject of classical electrodynamics, the analogous tendency is less marked, although here again emphasis is being placed on those examples that bring the student closest to the formalism of quantum electrodynamics. Such trends are of course proper and reasonable, especially so long as no important classical ideas are omitted from consideration. Indeed, the study of...