Present-day Physics Research Articles

Physics Textbooks: Annuals or Perennials?

The paper deals with present-day physics textbooks and the way in which they are being used. It criticizes the current practice of treating nearly all textbooks as ephemerals, and the suggestion is made that a basic general and comprehensive physics text should find a more lasting place in the education of the scientist.

A Criticism of Present-Day Physics

I am grateful for the attention which Philosophy has given to my little book Essay in Physics. The review by Professor McCrea brings out clearly its essential point, and criticizes it in a manner so wellbalanced and fair, and at the same time so penetrating, that it calls for a reply.

Science in the Core Curriculum

for all pupils, without regard to prerequisites, such as algebra or geometry, or to special abilities and aptitudes. This means, of course, that the science provided must differ greatly from the academic fare currently offered in high schools, though it does not preclude formal electives such as present-day physics or chemistry. It means a program which will insure the use of science in pupils' daily living and which will have a share of the school's time and services ully ompar ble to that of any other core learning field.

Prof. Gustav Jäger

IN Gustav Jäger, whose death at seventy-three years of age occurred on January 21, Vienna has lost one of the last men who linked present-day physics with the classical period of the Viennese school as represented by the names of Stefan, Loschmidt and Boltzmann, and moreover one who had an unusually wide and all-round knowledge of physics. After several years of study in the laboratories of Stefan in Vienna and Helmholtz and Kundt in Berlin, he became assistant first to Stefan and later to Boltzmann. In 1905, he was appointed professor at the Technische Hochschule in Vienna, and then was called in 1918 to fill the chair of theoretical physics at the University of Vienna, which had formerly been held successively by Stefan, Boltzmann and Hasenohrl. In 1920, Jäger changed this chair for the directorship of one of the University institutes of experimental physics. Generations of students have listened to his lecture courses, and greater still is the number of those who were introduced to the elements of mathematical physics through his “Theoretische Physik”, published in the handy volumes of the “Sammlung Gosehen”, and distinguished by clarity as well as conciseness.

Relativistic wave equations

The classical relativistic connexion between the energy p t of a free article and its momentum p x , p y , p z , namely, p t 2 — p x 2 — p y 2 — p z 2 — m 2 = 0, (1) leads in the quantum theory to the wave equation { p t 2 — p x 2 — p y 2 — p z 2 — m 2 } ψ = 0, (2) where the p 's are understood as the operators iħ ∂/∂ t , — iħ ∂/∂ x . . The general theory of the physical interpretation of quantum mechanics requires a wave equation of the form { p t — H} ψ = 0, (3) where H is a Hermitian operator not containing p t , and is called the Hamiltonian. The obvious equation of the form (3) which one gets from (2), namely, { p t — ( p x 2 + p y 2 + p z 2 + m 2 ) ½ } ψ = 0, is unsatisfactory on account of the square root, which makes the application of Lorentz transformations very complicated. By allowing our particle to have a spin, we can get wave equations of the form (3) which are consistent with (2) and do not involve square roots. An example, applying to the case of a spin of half a quantum, namely, the equation { p t + α x p x + α y p y + α z p z + α m m } ψ = 0, (4) where the four α 's are anti-commuting matrices whose squares are unity, is well known, and has been found to give a satisfactory description of the electron and positron. The present paper will be concerned with other examples, applying to spins greater than a half. The elementary particles known to present-day physics, the electron, positron, neutron, and proton, each have a spin of a half, and thus the work of the present paper will have no immediate physical application. All the same, it is desirable to have the equation ready for a possible future discovery of an elementary particle with a spin greater than a half, or for approximate application to composite particles. Further, the underlying theory is of considerable mathematical interest.

Grondbeginselen van de Hedendaagse Natuurkunde

IF teachers of elementary physics are to keep up to date and to render their courses of instruction attractive, it is essential that they should be able to obtain accurate information of recent advances and their incidence on old knowledge, in a readable form. This little book appears to provide such information. It deals with the fundamental concepts of physics in a way which undoubtedly has great pedagogic value. The subject matter is attractively arranged, nicely set forth, very well illustrated, and the book provides a singularly neat introduction to present-day physics, in which practically all the important results of modern research have been incorporated.

Geistige Arbeit

THE object of a new periodical of this title which appears twice monthly (25 pfennigs per copy) is to give brief reviews of the progress and tendencies of modern scientific research. The subjects considered cover a wide field, including anthropology, political economy, agriculture, sociology and all the pure and applied sciences. There are articles on peasants and nomads, problems of German sociology, new concepts of natural science, methods of counting for statistical purposes, Paracelsus (a sketch), and many others. The contributors are chosen from the ranks of those who have done original work in their respective fields. In the article by Moglich dealing with the foundations of present-day physics, we find due acknowledgment paid to the epoch-making ideas of Planck and Heisenberg, but there are important omissions which detract from the value of the account. In highly compressed articles of this type, it is of primary importance that the authors should have not only a deep insight into their subjects but also a proper sense of values, if the services of a discriminating censor are not to be invoked. Goethe has said: “Die Vernunft ist auf das Werdende, der Verstand auf das Gewordene angewiesen”. This remark applies particularly aptly to the present journal, which bears the sub-title “Zentralblatt fur die gelehrte Welt”. The article on Theophrastus Bombastus von Hohenheim, commonly called Paracelsus, is of interest as his name has recently come into prominence again as one of the first great experimenters in medical science-one hears of a Paracelsus Renaissance in Germany-in spite of a certain notoriety as a vagabond miracle-worker which he probably only partly deserved. His ideas, if not actual results obtained, undoubtedly exerted a considerable influence on later workers. The journal is published by Walter de Gruyter and Co., Berlin W.10, Genthinerstr. 38.

Permanent Elements in the Flux of Present-Day Physics

Permanent Elements in the Flux of Present-Day Physics

News and Views

PRESENT-DAY physics is in a state of flux. Rival theories have been advanced with startling rapidity to explain the ultimate structure of the atom—in so far as such an explanation may ever be possible. In their present state, such theories are of a professedly mathematical complexion and unfitted for universal consumption; some old conceptions are being discarded and others are being resuscitated. In a supplement to our issue this week, Prof. H. S. Allen gives a sketch of the rise of the quantum theory and in general terms its present position. To many who desire a clear statement of the case, such a summary will be interesting, but in a measure disappointing. As Prof. Allen points out, the position is as yet by no means cleared up. Are we to regard light as corpuscular or undulatory, or both? Has the electron an objective existence? Are the ultimate processes of Nature reversible or not? These are some of the questions to which an answer is eagerly awaited. We are in the position of a man standing before a looked safe which contains the answers to all the riddles of the universe. Around him are uncountable stacks of keys. By patient trial he has found some which nearly fit the lock. Perhaps the right key is among those which he has chosen and the non-success of his efforts to open the safe is due to faulty manipulation of the key. Perhaps, after all, the right key has yet to be tried.