sources for history of quantum physicscdn.calisphere.org/data/28722/8m/bk0016n8s8m/files/... ·...

S O U R C E S FOR H IS T O R Y OF Q U A N T U M P H Y S IC S

A project of the Joint Committee of the American Physical Society and the

American Philosophical Society on the History of Theoretical Physics in the Twentieth Century

Supported hy a grant from the IS؛ational Science Foundation

August 2, 1962

Professor Otto Stern 759 Cragmont Avenue Berkeley California

Dear Professor Stern:

I am grateful for your note of August 1st which auth orizes me to hear the tape-recording of your recollections which you hav e deposited at the E.T.H.Ziirich. I fully understand that this tape is intended only for the use of scholars working on the history of quantum mechanics and that no part of it is to be published in any form, at least not without your explicit permission. Those restrictions see m entirely suitable to me and I accept them without reservation.

I am also very grateful for your willingness to talk a bit about the development of the space quantization experiments over the .phone with me yesterday. Your remarks interested me a good deal, but there is one set of them that puzzles me, and I wonde r whether you would be willing to explain it a bit further. On the telepho ne you said that before the invention of wave mechanics and the dis covery of electron spin there had been no way of knowing how your exp eriment would work out. The experiment was, you suggested, simply a qu estion posed to nature. The result could neither be predicted in adva nce nor understood after it was gained.

But in your first paper on the subject, ؛ ؛ Ein Weg zur ex perimentalen Prtffung der Richtungsquantelung im Magnetfeld," Zeitschr. f. Physik (1921), pp. 249-253, you undertake a derivation to show t hat, if there is any space quantization, then a beam of one-electr on atoms should be split in two by an inhomogeneous field. F or me this raises two questions, though I fully realize that it may be im possible now to find answers to either of them. Apparently you did have so me notion of what might be expected if there was really space quantization i n nature. But did you really believe that there was? That i s, did you think the outcome of the experiment was likely to be negative? Obviously, there were good reasons to feel that it would be and you outline these very successfully at the beginning of your own paper. The other problem is of a somewhat different ,sort. Y our argument that the beam will split into two components is based on the hypothesis that the magnetic moment of the atom must line up either

Staff

Thomas S. Kuhn

John L. Heilbron

Stephens Memorial Hall University of California Berkeley 4, California

Joint Committee

John A. Wheeler

Palmer Physical Laboratory Princeton University

Princeton, New Jersey

Richard H. Shryock

American Philosophical Society Philadelphia, Pennsylvania

George W. CornerExecutive Officer

American Philosophical Society

Karl K. DarrowSecretary

American Physical Society

Gerald J. HoltonHarvard University

Henry Allen MoePresident


Frederick SeitzPresident


George E. UhlenbeckRockefeller Institute

J.H. Van VleckHarvard University

S O U R C E S FOR H IS T O R Y OF Q U A N T U M P H Y S IC SSekretariat of Professor Niels Bohr, Gl. Carlsbergvej 15, Copenhagen-Valby, Denmark


American Philosophical Society on the H istory of Theoretical Physics in the Twentieth Century

Supported by a grant from the National Science Foundation

AIRMAIL

Professor Otto Stern 759 Cragmont Avenue Berkeley, California


Shortly before I left Berkeley last summer, you kindly wrote me a short note authorizing me to hear the tape you have deposited at Zurich subject to the condition that none of the material it con�tains be made public. I then expected to be going to Zurich myself and very much looked forward to listening to the recording. Clearly, this project badly needs to know the sort of material it con�tains.

To my regret, however, it now looks as though I may not be getting to Zurich at all this year, and I shall certainly not be going there for some time. Meanwhile, my colleague, John Heilbron, is planning a trip there to take place shortly after the first of the year. Both he and I will be very grateful if you will grant him the same authorization with which you favored me. I can personally assure you that he is a thoroughly reliable and conscientious student of the field.

I hope you are having a comfortable and pleasant winter in Berkeley. Until a week ago our work here was proceeding very fruitfully, and we were all much encouraged for the project's chances of success. Professor Bohr's unexpected death has now greatly reduced that promise. For personal reasons as well we are all greatly upset by it.

Copenhagen, Denmark November 27. 1962

Staff

Thomas S. KuhnDIRECTOR

John L. HeilbronASSISTANT DIRECTOR

Joint Committee

John A. WheelerCHAIRMAN

Palmer Physical Laboratory Princeton University Princeton, New Jersey

Richard H. ShryockCOCHAIRMAN AND SECRETARY






S. A. GoudsmitBrookhaven National Laboratory


W. V. HoustonPresident





J . H.Van VleckHarvard University

Sincerely ٠ / /

Thomas S ٠ Kuhn Director

BLEGDAMSVEJ 17

CO PEN HAGEN , DENM ARK

TELEGRAMS: PHYSICUM . COPENHAGEN

M a r c h 27, 1962.

UNIVERSITETETS INS TITUT

TEORETISK FYSIK

Dear Professor Kuhn,

Thanks for your kind letter of February 15 with the en closed material. A s you know, we have for years here in Co penhagen been deeply interested in the history of atomic physics i n our century, when there has been such intense and exten sive international collaboration. W e therefore look forward with keen anticipation to the results of your great project and especially to the o pportunity of personal discussions with you.

During the last years I have myself been increasing ly occupied with historical matters, and as a small pre liminary step I have published som e of m y reminiscences of Ruther ford and of developments based on his work. 1 also contributed to the recent Heisenberg volume a short article, reviving so m e m e m o r i e s f rom the years of the advent of quantum mechanics. Repri nts of these two articles are being sent to you under separate c over. At the m o m e n t I a m completing a manuscript about the histo ry of the Solvay meetings, containing a somewhat elaborated version o f a talk delivered at the Jubilee Conference last autumn .

T o facilitate such work, a Secretariat has been est ablished on the area of the Carlsberg Breweries, where I hav e m y home, and all historical material in m y possession has be en assembled there. Just now this Secretariat is in the process of being extended, and by September rooms will be available for you an d your staff.Of course, close connection is kept with the Institute of T heoretical Physics, where a larger group is working under the guidance of m y son and others, and where the physical ma in libr ary is. Still, at the Secretariat I think we have m u c h of the lite rature which you m a y need for your work, and various facilities for reproduction of documents in which you m a y be especially interested. W e therefore hope that you will find convenient working conditions during your stay in Copenhagen.

With kindest regards, and looking forward to seeing you

here,

Sincerely yours,

Niels Bohr

letter which will give you some idea of the extent of hi s interest and support.

You will already have anticipated the intent of my letter: we areeager to make definite arrangements for a series of di scussions with you. They could be held at any place and almost at any time of your choosing. Professor Rudolph Minkowski has said that he would gladly partici pate also if you would like him to. If he does we could as easily h old the conver�sations in German as in English. Finally, let me say again that you may place any restrictions that you think appropriate upon the accessibility of the tapes and transcripts. Our only concern is t o be sure that they will ultimately become available to sufficiently qualified scholars.

If you have any other questions about the project, I s hould be very grateful for an opportunity to ansvfer them, and would be g lad to call upon you for that purpose. I can be reached by telephone e ither at the Univer�sity, extension 2lkh9 during the day, or at home, THornwall 3-0^32, in the evenings. I very much look forward to hearing from you. Y our participa�tion can make a gigantic difference to the project’ s success. Both bec�ause of your own work and because of your active coll aboration with Einstein in the early days of the quantum theory, we lo ok upon you as one of the few most significant people we must see.

Sincerely yours,


A project ه ه the Joint Committee ر the American Physical Society and the ر

American Philosophical Society on the History 0أ Theoretical Physics in the Tmtieth Century

Supported, by a grant ١rom tbe IS؛ational Science T?oundation

May 16, 1962



In the hope that you have by now returned to Berkeley, I write once more to ask your help in this project.s attempt to prese rve records of the development of quantum physics. Before making that req uest more concrete, let me give you some additional information ab out our object�ives, present state, and future plans.

I believe you know already that our aim is predominantly arc hival. lie hope, that is, to succeed in preserving manuscripts and tape-rec orded recollections of the main participants in the development of quantum physics. These records are to be deposited at the librari es of the Amer�ican Philosophical Society and of the University of California, Ber keley. After the project closes they will be made available — su bject to what�ever restrictions the donors may desire — to schola rs attempting to recon�struct the development of physics in this century. If we are at all successful, the project’s work should make future hist orical studies more accurate and more illuminating. The preparation of tho se studies is not, however, any part of this project's function. Our only pu blication will be a descriptive catalogue of the materials our work has made available. Some of those materials will probably not be generally accessible, even to qualified scholars, for a number of years.

We are now at the end of the first year of our research, mo st of which has been devoted to preparation. He have been trying to study the published record, determine whom we must see, and dis cover the problems with which they are most likely to be able to help us . But we have also had one or more preliminary interviews with a number of the partici pants in the development of quantum physics. These include Professors L. Brill- ouin, P.J. Debye, P.A.M. Dirac, F.P. Ewald, A. Land e, F. Reiche, and G.E. Uhlenbeck. In addition, we have scheduled inter views with a number of other people. Later this month I shall begin talks with Professor S. Groudsmit, and my colleague, John Heilbron, will t ravel south to talk with Professors P.S. Epstein, W. Elsasser, and C. Eckart . During July, Professor Maria Mayer and I go to Cape Cod for extended disc ussions with Professor James Franck and his wife. Early in the fall we shall be moving to Europe to continue the program there. Professor Bohr has kindly offered us his active collaboration, including the provisio n of an office that is now being added to his Secretariat at Carlsberg. I enclose a copy of a

Staff

Thomas S. Kuhn

John L. Heilbron


Joint Committee

John A. Wheeler

Palmer Physical Laboratory Princeton University Princeton, New Jersey

Richard H. ShryockCO CH A I RM A N AN D SE CRE T A RY












J.H . Van VleckHarvard University



American Philosophical Society on the History of Theoretical Physics in the Twentieth Century

Supported by a grant from the National Science Foundation

July 30, 1962



There are now only ten days before this project closes its office here and begins its trip to Copenhagen. I wonde r whether by any chance you would be willing to see me once more before our departure. If so, I should like very much to ask you about the origins of your work with molecular beams and about the development of the famous experi ments on space quantization.

It would please me greatly if you had at all changed your mind since our last meeting. I am still very grateful for the help you have already given us and hope that you may possibly be willing to continue for a bit longer. If not, however, may I at least hold you to your promise and as k that you send me a note authorizing us to listen to the tape which you prepared a few years ago in Europe. We should certainly like to take advantage of its existence during the coming year abroad.

Sincerely,

Thomas S. Kuhn, Director

Staff

Thomas S. Kuhn

John L. Heilbron


Joint Committee

John A. Wheeler

Palmer Physical Laboratory Princeton University

Princeton, New Jersey

Richard H. ShryockCO CH A I RM A N AND SE CRE T A RY












J.H . Van VleckHarvard University

parallel to the field or anti-parallel. Apparently, y ou see no possibility of an alignment perpendicular to the field. Sven in the absence of wave mechanics and electron spin, that might have seemed a possible a lignment.Do you by any chance, have a notion why you did not take that possibility into account؟

I am sorry to bother you with these questions of detail about work done long ago. But they are just the sorts of questions that will bother me and my colleagues later on. I should be immensely gra teful for any help you can give us with them, as I am already grateful for what you have already done.

Sincerely,

Thomas S. Kuhn, Director

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