No abstract

No abstract

An experimental study of the dust striations in a Kundt's tube has been carried out using a loud speaker, operated from a vacuum tube oscillator, as a source of sound. It is found that the positions of the vibrator for maximum agitation of the dust is different for the case in which a loud speaker is used from that obtained when a stroked rod is used. The formation and behavior of the striations is described in detail. It is found that the spacing between the striations increases with the intensity of sound, decreases with an increase in pressure of the gas, and decreases with an increase in density of the dust material. A minimum spacing is found when the size of the dust particles is changed. The relation suggested by Cook that the ratio of the separation of the striations to the mean free path is a constant was tested but the results obtained indicated that such a simple relation does not exist. 1

In a previous paper the writer derived an approximate expression for intensities in the electronic vibrational bands of symmetrical diatomic molecules, based upon the Franck-Condon theory of transition probabilities. In the present paper the approximation is carried further, by removing the restriction that the oscillations be linear. An extended formula is given making use of the Schrodinger theory of perturbations.Calculations using this perturbation theory formula are carried out for the hydrogen absorption band spectrum. It is shown that the agreement with experiment is much improved over that obtained on the assumption of harmonic oscillations. Calculations are also made using Morse's potential function in which case the agreement is still further improved, especially for the higher transitions.

This article represents an attempt to achieve two objectives. The first is a response to William T. Knox's invitation, directed to some scientific disciplines, for each discipline to present a concept of its information system and discuss the compatibility of that system with the proposed national networks. The second objective is to present this same concept to the physics community since it will have major bearing on future physics research and education. The first portion of this article serves this dual purpose. The second portion is intended to tell physicists about current developments in areas of interest to them.