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Hans Kuhn and the Analogue Computer



                   Hans Kuhn in 1998
Hans Kuhn, 1998
Photo and © U. Anders
                   Hans Kuhn, born in 1919 in Bern, Switzerland, studied chemistry at the ETH Zuerich and later at Basel, postdoced with Pauling in 1947, became professor at the Univ. of Basel (Switzerland) in 1951, went to Marburg (Germany) in 1953.

It was there at Marburg, around 1960, where the realization of the analog computer, spelled "analogue" computer in those days, took place.

It was a unique realization in the history of quantum chemistry. It had as such neither ancestor nor successor. This forgotten detail will be presented here in more detail.

This page will get enhanced as time goes on - keep dropping by.)



Kuhn stated the start of his ideas about the 'analog' device in one of his papers of 1953:

H. Kuhn,
Chemische Bindung und Zustände von Elektronen in Molekülen.
Experientia 15, 41-61, (1953)

where Kuhn wrote on page 60:

"Es ist daher beabsichtigt, die in Abschnitt 7a beschriebene akustische Analogierechenmaschine zur Untersuchung der Zustände von pi-Elektronen in Molekülen zu verwenden und ferner ein elektrisches Analogiegerät zu benützen, um den Einfluß des Potentialverlaufs entlang einer komplizierter gestalteten Molkülkette zu untersuchen (diese Möglichkeit ergibt sich auf Grund der Tatsache, daß bei Betrachtung gewisser elektrischen Siebketten dieselbe Differentialgleichung auftritt, welche auch das Verhalten von pi-Elektronen in einem Feld veränderlicher potentieller Energie beschreibt (1) )." Engl. Translation:
"It is therefore planned to use the accoustical 'analog calculating device' { this website: this is a word construction of Kuhn; the transliteral sense would be more like 'mechanical-accoustical device based on the analogy to a vibrating membrane' }, as outlined in part 7a { of this paper } for the states of pi-elctrons in molecules. Also planned is the use of an 'electrical analogy device' { this website: also a word construction of Kuhn, later to be changed to 'analogue computer' } in order to investigate the potential flow along a more complex molecular chain ( this possibility results from the alikeness of the differential equation for electrical filter chains with those which describe the behavior of pi electrons in a field of changing potential energy (1) )."


There H. Kuhn gave the following 2 references to G. Kron's papers:

(1) G. Kron,
Electric Ciruit Models of the Schrödinger Equation.          Read it here.
Phys. Rev. 67, 39-43 (1945).

G. Kron
Numerical Solution of Ordinary and Partial Differential Equations by Means of Equivalent Circuits.          That one is here.
J. Appl. Phys., 16, 172 (1945).

Who was Gabriel Kron? Details right here.



1.) F.F. Seelig, W. Huber H. Kuhn,
Analogiebetrachtungen und Analogrechner zur Behandlung der Korrelation von Pi-Elektronen.
Z. Naturforschg., 17a, 114-121 (1962).


2.) H. Kuhn,
Analogiebetrachtungen und Analogrechner zur quantenmechanischen Behandlung der Lichtabsorption der Farbstoffe.
Chimia, 15, 54-62 (1961).





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Copyright © July 8, 2003 by U. Anders, Ph.D.
e-mail Udo Anders : udo39@t-online.de

Last updated : Oct. 03, 2003 - 18:37 CET