# Johannes Kepler Symposium on Mathematics

As part of the Johannes Kepler symposium on mathematics
**em.Prof. Dr. Dr.E.h. Dr.h.c.mult. Erwin
Stein**, Institut für Baumechanik und Numerische Mechanik, Leibniz Universität Hannover,
will give a public talk (followed by a discussion) on **Thu, Nov. 10, 2005**
at **18:00 o'clock** at **HS 10**
on the topic of
"Gottfried Wilhelm Leibniz - far ahead of his time"
. The organziers of the symposium,

Univ.-Prof. Dr. Gerhard Larcher

A.Univ.-Prof. Dr. Jürgen Maaß, and

die ÖMG (Österreichische Mathematische Gesellschaft),

hereby cordially invite you.

Series A - General Colloquium:

The intention is to present general information not only to experts, but also to students and guests from outside the mathematical institutes.

### Gottfried Wilhelm Leibniz - far ahead of his time

The design and research for our (so far seven) Hannover Leibniz Exhibitions since 1990, entitled "Gottfried Wilhelm Leibniz (1646-1716): Philosopher, Mathematician, Physicist, Engineer,...", follows the intention "Leibniz for touching and understanding" by presenting the key ideas of his multi-ingenious intellectual achievements in the so-called 'Leibniz worlds' with his postulates "Theoria cum Praxi" and "Commune Bonum" and showing new fully functional and vivid models of his technical inventions, especially his calculating machines, in the second half of the 17th century which is often called 'the cradle of modern natural sciences and engineering technology'. After an introduction into Leibniz' guidelines of thinking in humanities as well as the key points of his inventions in mathematics and physics, a major part of the lecture treats the history of his decimal "Four-Function-Calculating Machines" from 1673 and 1693-1695 and of the "Machina Arithmeticae Dyadicae", the binary calculating machine, described in 1679. Special attention is given to the principal and technical insufficiencies of Leibniz' machines, furthermore J. T. Lehmann's replicas of the "large" decimal Four-Function Machine, built in Dresden in the 80th of last century, and L. von Mackensen's first design of Leibniz' binary machine for adding and multiplying from 1969 in Munich, built by the Deutsches Museum München in 1971, as well as our new-designed models which overcome the shortcomings of the originals and the former replicas in regard of the authenticity with the original machines to the greatest possible extend. Also Leibniz' major technical developments for mining in the Harz mountains with the goals of saving human efforts and energy are outlined by Powerpoint pictures. The lecture ends with considerations on his philosophical concepts and with reflections on the restless personality of this so-called last universal scholar.