Year: 2023

A FORCE-FREE MAGNETIC FIELD SOLUTION IN CYCLIDAL COORDINATES

There are no known analytic solutions to the force-free magnetic field equations in coordinates representing Dupin cyclides. Here it is shown that force-free fields can not only have solutions for toroids, as was shown in an earlier paper, but also for cyclides. The fact that the curvature lines of Dupin cyclides are all circles is used to derive a force-free magnetic field on the surface of an elliptic Dupin cyclide.

The paper is available at: http://arxiv.org/abs/2310.17673

OPPENHEIMER

A LETTER TO SCIENCE MAGAZINE IN RESPONSE TO AN ARTICLE BY ADRIAN CHO IN THE 21 JULY 2023 ISSUE

To the Editor,

In his article about Oppenheimer Adrian Cho interviewed David Cassidy about Oppenheimer and in his final question stated that “Oppenheimer lost his security clearance in part because he opposed the development of the hydrogen bomb”.  This is incorrect and probably comes from the transcript of In the Matter of J. Robert Oppenheimer, published by the Atomic Energy Commission, of the hearings that led to Oppenheimer’s clearance being revoked. 

K. D. Nichols, then General Manager of the Atomic Energy Commission surely new that Oppenheimer never opposed the hydrogen bomb, only Teller’s Super.  He did so because he thought that the Super would divert valuable resources away from fission weapons development.  After a meeting of the GAC held at Princeton during June of 1951, Oppenheimer changed his mind and enthusiastically supported Teller’s new “technically so sweet” approach.  This was when he was first exposed to the Teller-Ulam idea for the hydrogen bomb. 

It was David Rosenberg, who is now one of the country’s foremost historians of the nuclear age, had succeeded in obtaining a declassified copy of the AEC Thermonuclear Weapons Program Chronology, which gave a clear description of the Super.  It was nothing like the description of the hydrogen bomb.  I subsequently learned from I. I. Rabi that there had been closed secret sessions during the Oppenheimer hearings where Oppenheimer could well have defended himself against Nichols’ charge by drawing the necessary distinction between the classical Super and the hydrogen bomb.  I have no idea to this day whether he did so or not.

USA Today Magazine Articles 2001-2023

This book gathers together the articles I published in USA Today Magazine. They cover a large variety of topics and the book contains a commentary, sometimes giving history and technical details that could not be included at the time.

https://www.lulu.com/shop/gerald-marsh/usa-today-magazine-articles-2001-2023/paperback/product-em22p8.html

A FORCE-FREE MAGNETIC FIELD IN TOROIDAL COORDINATES

While there are no known analytic solutions for force-free magnetic fields in toroidal coordinates, with a reasonable boundary condition it is possible to find a solution for the surface field and, with a restriction on the form of the field, to the interior of the torus as well. Published in Physics of Plasmas (vol. 30, Issue 5); online 17 May 2023.

Here is the link to the paper:

http://www.gemarsh.com/wp-content/uploads/POP23-AR-00182.pdf

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