Jerrold R. Zacharias

Some New Applications and Techniques of Molecular Beams

Publisher Summary This chapter presents molecular beam as a tool in technical applications, such as in the measurement of magnetic fields, the measurement of acceleration, the measurements of length, information storage, and isotope separation. The observations should be made on the molecules of the beam so that when the interference fringes pass over the beam, the number of molecules that are affected by the light will undergo a periodic variation. Then only Doppler effect and the resonance line width of the molecules of the beam limit the path difference, which can be tolerated in the interferometer. The chapter also discusses the sources of neutral molecular beams. The detectors of neutral beams is described in the chapter that falls into two broad categories; those which give a direct measure of the beam intensity—for instance, by ionizing the molecules and measuring the resultant ion current—and those in which the effect of the beam on some suitably sensitive device, such as a highly refined manometer, gives an indirect measure of the beam intensity. The chapter assists new users of molecular beams by providing the descriptions of more or less conventional molecular- beam components with suggestions for future development.

A Laboratory, Computer and Calculus Based Course in Mathematics

Summary The paper describes the designing and testing of a laboratory, computer and calculus based course in mathematics. The laboratory is central to the course and stimulates in the student the need and desire to know more about mathematics. Further, it enables mathematics to be taught in a real world context. Computers are used to take the drudgery out of the mathematics and make it possible to attack real scientific and technical problems. This new approach to calculus is less formal and depends to a smaller extent upon prior mathematical training so that it appeals to a much wider audience. The proposed course, with its emphasis on laboratory measurements, is ideally suited to the exploration of numerical methods and their application to the calculation of derivatives, definite integrals and the solution of differential equations.

Team Approach to Education

The Response of the Oersted Medallist to the American Association of Physics Teachers, February 2, 1961.

Common Sense and Nuclear Peace

The authors note that arms control, arms limitation, and arms reduction, though moving in the right direction, are not sufficient. Possible escalation of a small-scale war between nuclear superpowers or of an accident into a major conflagration is our greatest worry, they think, even though there is no justification for ever resorting to nuclear weaponry. We must find new ways to prevent and resolve conflict among nations other than military solutions. Further, the stakes are too high to leave the settling of international disputes in the hands of the worlds military establishments, or even its anti-military establishments. To reduce and then eliminate the risk of nuclear war will require a profound change in attitude, both here and in the Soviet Union. The authors feel we must both learn to bargain and barter about the things that really matter. We must realize that we cannot compete on both economic and military trufs simultaneously, because they require different attitudes and policies. Good treaties based on commonality of interest make good neighbors, and can lead to a less-belligerent world. 17 references.

Testing in the schools: A help or a hindrance?

In an article in our regular feature ‘Viewpoints and Controversies’ entitled ‘Ability Tests? A Shot in the Dark’,1 the Soviet Academician Arthur V. Petrovsky defined the limits of a certain conception of mental development which he, for his part, saw as being directly governed by childrens social and cultural environment and the education they receive and not as a spontaneous process of revelation of intelligence. Based on unscientific presuppositions, tests, in his view, cannot measure the mysterious quantity labelled intelligence. Although thus expressing the strongest reservations concerning this scientifically unfounded method, he said at the end of his article that the argument, though it had gone on for a long time, was still unsettled. The American educator whose outspoken views we publish below returns to the charge from a different angle; far from invalidating Petrovskys arguments, he too denounces the obstacles to the renewal of educational methods, democratization and the universalization of genuinely scientific thought which tests multiply and institutionalize. And so the debate on tests continues. Our readers are invited to join in.

The case for nuclear electric power

What role should the United States play in the energy economy of the world? Do we want to be uninvolved? Do we sit back and let the other industrial countries supply the rest of the world with nuclear power? Already, the world with four billion people and too high a growth rate is headed for trouble that could engulf us all.

A Citizen's View of Our National Security

Criticism of American military policy, particularly of its reliance on atomic weapons, was recently voiced by a group of professors from Harvard and Massachusetts Institute of Technology in a letter published in the “New York Times” on April 30. In the following article, Dr. Zacharias, one of the signers of this letter, enlarges upon the arguments of this group.