From the February 11, 1933, issue


A commercial application has been found for the extremely efficient sodium-vapor lamp. A highway in Holland is now illuminated with these light units giving off an intense yellow glow; and this light, which makes color discrimination impossible and is devastating to Miladys makeup, is said to be especially desirable for outdoor illumination. The monochromatic character of the light apparently assists vision at the low intensities that prevail out of doors.

While this application is being pushed, sodium lamps will also prove more valuable in chemical laboratories where monochromatic light is required for analytical work, Ward Harrison, director of engineering at Nela Park, Cleveland, General Electric Lamp headquarters, believes.

The front cover pictures a sodium-vapor lamp set up for test in a spherical photometer.

Mr. Harrison, writing in Electrical World, said that it does not appear that the efficiency of sodium lamps will offset their inherent high cost except in sizes of 100 watts or more.


By allowing the heart of a helium atom to tune in on the heart of an aluminum atom, creating in it a sympathetic vibration, physicists of the Carnegie Institutes department of terrestrial magnetism at Washington have smashed the aluminum heart, or nucleus. This achievement by Dr. L.R. Hafstad was announced by Dr. M.A. Tuve in a lecture before the Franklin Institute of Philadelphia.

The first experiments on the resonance smashing or disintegration of atoms were performed by Dr. M. Pose in Germany, and the Carnegie scientists have now confirmed this work and carried it further. It is found that when the attacking alpha particle or wave, which is the helium heart, has the proper energy it penetrates the other atoms nucleus. In this case, the alpha particles of mass four from radium joined with aluminum of mass 27 and formed silicon of mass 30 and released hydrogen of mass one in the form of a proton or wave-particle of positive electricity.


Prof. Albert Einsteins first paper on the new quantum mechanics is soon to appear under the title Semivectors and Spinors.

He has just allowed his colleagues in theoretical physics at the California Institute of Technology at Pasadena, Calif., to have an advance view of some of the ideas contained in this forthcoming paper, which will be published in the Proceedings of the Prussian Academy at Berlin, with Dr. Walter Mayer as collaborating author.

Prof. Einstein is careful to explain that most of the results had already been discovered by other workers. But he wrote the forthcoming paper at the request of his friend, Prof. Paul Ehrenfest of Leiden, to clarify this little known subject.

His discussion with the theoretical physicists was, of course, technical. To make it easier for his American listeners, Einstein spoke English. This is the first extended discussion he has delivered in English. Usually he chooses to use German in order to express himself more precisely and clearly. His English is, however, quite good.

Semivectors are related to vectors in somewhat the way that imaginary numbers are related to real numbers. The spinors are restricted semivectors. The vector concept is fundamental in relativity because it enables one to avoid irrelevancies. Thus it helps discover new laws.

The semivector may suggest new physical laws also for it has the same simplifying properties as the vector. As in the case of the vector, the semivector can furnish tensors. The famous equations of Lorentz can be written for semivectors, but no important change is involved. The Dirac equation for an electron can be derived in an elegant manner, but Prof. Einstein pointed out that it was not the simplest case of its type.

He said it would be interesting to study the simplest case. Then he went on to say that semivectors could be used to advantage in generalized relativity but that unlike vectors they led to complicated equations.

When Prof. Richard C. Tolman of the California Institute of Technology asked for a physical description of a semivector, Prof. Einstein confessed he had been unable to think of any geometrical or physical picture but added that with mathematical analysis, the subject could be handled with great ease.

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