# Some introductory notes on the colloquium posters

A favorable resonance to the posters which I have had the opportunity to draft for the Department of Mathematics during more than a decade permits me to present a selection of them to a wider audience. A few explanatory comments which precede the presentation may help to elucidate the background.

**»Colloquium«: an Academic Institution**

Most academic departments have a tradition of colloquium lectures. But these traditions vary greatly. A colloquium lecture is, as a rule, a lecture by an invited guest reporting on scholarly material pertaining to his field of expertise; alternatively, it may present a survey on recent developments or on the historical genesis of a sub specialty close to the speaker's field. Some traditions provide a regularly scheduled time slot for the »Colloquium«, others may allow for guest events scheduled irregularly as the occasion arises. Notably, mathematics departments all over the world have a tradition of these colloquia, and these traditions are just as motley.

**The Darmstadt Mathematical Colloquium**

In the summer term of 1983, the Mathematics Department of the University of Technology at Darmstadt, at the insistence of Rudolf Wille primarily, decided to institutionalize its »Mathematical Colloquium« in a rather ritualized fashion. The time slot for the colloquium is fixed in the middle of the work week, on Wednesday, at 5:15 p.m., allowing for the traditional academic quarter. Tea is being served in the lobby half an hour earlier. No other events, courses, seminars, lab sessions, tutorials are scheduled at this time in order to allow all constituencies of the department to participate if they wish. The schedule for the projected colloquia during a given semester is completely set up by the end of the previous term and publicized well before the semester starts. All faculty members of the department participate in the programming of the colloquium by suggesting speakers; as a rule, the invitation is organized by the person having proposed the guest. There is a Colloquium
Coordinator who is supported by a committee of two colleagues; this group is responsible for the colloquium and its operations.

As an attachment to their invitation letter, guest lecturers receive a text which bears citing, because it illustrates the department's effort to have the lecturers make their presentations accessible to a wide audience.

*The Mathematical Colloquium at the University of Technology Darmstadt is a jointly organized event at the School of Mathematics serving students and faculty alike and providing information on topical research subjects in a mathematical specialty, in the history of mathematics, the teaching of mathematics, or in an interdisciplinary area touching mathematics. Lectures may be devoted to a survey or an individual subject matter.*

*A colloquium lecture should be designed to be accessible in its exposition and a large portion of its presentation, to a wide audience of mathematically educated persons including students and members of adjacent schools. The School of Mathematics has a special and different program of communications of technical contents addressing specialists. Therefore, a basic characteristic of the Mathematical Colloquium is its intent to address an audience of all members of the School of Mathematics and interested parties from other disciplines. *

**Darmstadt Colloquium Posters**

Most mathematics departments have, in the framework of their colloquia, an institution which is as time-honored as it is fearsome to the guests: The colloquium book, a perverse form of a guest book. Come hell or high water, the guest will have to write an abstract of his lecture into this book and sign his name as a perennial souvenir for the inviting department - presumably never to be looked at again. The service, paid for by the honorarium (rather measly in recent years of economic exigency) and by the compensation for travel expenses, is to be considered incomplete as long as that entry is not yet in the book. As a particular favor, the guest is perhaps allowed to take the valuable commodity into his hotel in the evening, where the writer of the abstract not only has to worry about his text but how he gets the book back to the department in the morning.

There is no colloquium book in Darmstadt. Yet at least the titles and topics of the lectures are committed to memory even more permanently through a unique institution: The Darmstadt Colloquium Posters. As soon as the guest sets foot into the entrance hall of the Mathematics Building the poster announcement greets the new arrival. The tradition of the Colloquium Posters dates back to the »New Series« of the Darmstadt Mathematica Colloquia beginning 1983. The posters go into an archive, and so a substantial body of material has accumulated.

**The Posters**

A poster is a piece of graphical design whose purpose is the advertising of a product or a service. Accordingly, it combines typographical with figurative designs. The printed message is normally supported or emphasized by a pictorial representation meant to draw the viewers' attention to the message.

The advertising of a mathematical lecture is a challenge. On the one hand, it is certainly true that many pieces of mathematical content themselves have a graphic representation. Indeed most mathematicians have a spacially oriented visual intuition rather than a verbal one; conceptual thinking normally goes along with virtual images which mathematicians generate in their minds and which they do not always promulgate. Most teachers of mathematics, however, do appeal to this mode of conceptualizing by drawing sketches on a wall board or by interspersing the prose of a text book with diagrams. Yet, on the other hand, in advanced texts, monographs, and in articles in technical journals this practice is shunned: it has become the fashion that the author expects the reader to form an intuition by creating the helpful mental images himself.

All of this, however, is rather useless for advertising a mathematics lecture on a wall poster. The designer of the poster has a task of persuasion different from that of the mathematician who has to convince a listener or a reader of a logical truth; instead he has to attract the attention of persons while they hastily pass a particular spot on the way to the daily routines. This objective may be accomplished by an attempt to entertain and to disrupt, somehow, the routine. It would be best served if the poster succeeded in causing the passer-by to pause just a minute and satisfy one's curiosity about how the poster designer tries to allure the members of the department again this week. The poster designer has a feeling of success if the janitors tell him that every week they stop and look what is up - irrespective of their personal attachment to the subject matter that is being advertised.

The titles of many lectures do not yield themselves very well to an illustrative design. Often a cartoon has to take over, sometimes via an atrocious pun; these often depend on the language and do not travel into a translation. Sometimes it helps to find a reference to some current media event that most viewers know and are able to connect with the poster design.

Therefore, the Darmstadt Colloquium posters are often cartoons and have reached a status of being expected to be like a comic strip. The task of the artist is a divided one: He has to be a mathematician to anticipate even faintly the topics which are transacted in the lectures ; he has to be a cartoonist not unlike the political cartoonists in the print media; he has to be a typographer of sorts to transport the written message on the poster, and he has to be enough of a designer to combine all of these components into composition which satisfies basic demands on the composition of a piece of graphical design. I had to learn the hard way that the graphically superior designs did not necessarily make for the most popular and most effective posters. Occasionally, the depicted contents of the designs are not transparent at first glance (either by design or by lack of better ideas); the viewers then begin to speculate about the intended meaning; this often turns out to be an effective way
of catching their attention.

**Techniques**

The actual production of the posters is fairly primitive. The designer has a small studio in the library of his group. This studio consists of a table and a sink. The equipment is rudimentary. Paper is secured by cooperative personnel, janitors and secretaries who solicit local newspapers, print shops, or publishers for surplus paper. The donations we get are rolls of residual material that serves us well. What we now have is glossy paper of the kind used for illustrated magazines. The format of the posters is (approximately) 1.20 x 0.45 m. They are posted in the entrance hall of the Mathematics Building; indeed, they used to be pinned openly to a pin wall on top of a permanent card board with large permanent lettering referring to the Mathematical Colloquium. More recently, after thefts of posters started occurring, they are magnetically pinned up under glass and lock.

The medium originally was felt pens of various colors; it is now a combination of felt pens and tempera paints. The typography is largely determined by these media. The production of the posters takes place on weekends, Saturday or Sunday.

The two paragraphs above describe the situation from 1983 through 1998. During the years 2000 forward, the Dean's office started materially supporting and investing into the creation and archiving the posters. So, the department ordered the storage facilities for the originals and had the entire collection digitalized. This allows its presentation on the website and, in the last evaluation, also the presentation as videos. The entire collection will be transferred from the department to the University Archives.

My first art courses I took in high school from Eduard Waldraff in Geislingen; he influenced me at an early stage and taught me for the first time graphical techniques like linoleum and wood cutting as well as etching. At the University of Tübingen I studied art with Gerd Biese. German universities do not teach studio arts. It appeared to be a specialty of the University of Tübingen to have a »University Instructor for Drawing« who would, among many other art pedagogical tasks, give courses to students of the natural sciences in the wonderful studio under the glass roof of the »New University Building«. He taught me in courses on landscape drawing, in theory of composition, in wood cutting and in lithography. I took lecture courses in art history at the University of Tübingen from Wilhelm Boeck and Hubert Schrade. Since those days the Middle-Ages and mediaeval art have fascinated me, and occasionally this predilection surfaces in the designs of the posters. My academic teachers in
mathematics at the University of Tübingen were Bertram Huppert, Erich Kamke, Hellmuth Kneser, Max Müller, Günter Pickert, Helmut Wieland and Karl Zeller.

**Acknowledgments 1983 - 1998**

I owe thanks to the Department for its moral support; Benno Artmann, Jurgen Lehn, and Gerlinde Gehring for their steady encouragement. The latter, in particular, organized the archive. Without her input this enterprise could not have been undertaken. I thank Wolfgang A. F. Ruppert for photographing the first batch of posters and for his assisting me in the organization of this catalog, and Gerhard Bruhn for the photo exhibition in the tea lobby. Norbert Schmitz of the Institute of Mathematical Statistics of the University of Munster greatly encouraged me by his correspondence on a possible publication of the posters. Gerd Fischer of the University of Düsseldorf was a professional photographer of the second batch of posters; as Editor of the Mitteilungen der Deutschen Mathematiker-Vereinigung he published a selection in Volume 1996 pp. 22-35, many of which are reproduced in this collection. Helmut Mäurer wrote a preface for this publication for which I am very grateful.
Renate Gruber professionally photographed the third batch needed for completing this reproduction. Angelika May of the Munich University of Technology rendered active support to this catalog project. I thank the President of the Darmstadt University of Technology, Prof. Johann-Dietrich Wörner most cordially for the preface to this anthology.

My colleague Prof Dr. Günter Ziegler of the Berlin University of Technology and the librarians of the Mathematics Library of the Technical University of Berlin, Dr. Iris Hahnemann and Ms. Bärbel Erler organized so competently the Retrospective on the occasion of the International Congress in Berlin 1998; I am deeply grateful for their enthusiasm and professionalism. No one could have produced a more beautiful book than the Department of Typography (»Lehrdruckerei«) at the Darmstadt University of Technology. Their
contribution, materially and artistically, was essential. Without the persistent encouragement and collaboration of Isolde Hofmann, M. A., the book of 1998 would not have materialized. It is therefore dedicated to her.

**Acknowledgments 1999 - 2018**

It is owed to the steady and forceful support of Gerlinde Gehring that the entire collection of colloquium posters was digitalized and archived. She was also instrumental in the negotiations between the Department and the University Archive towards an eventual preservation of this material. Last but not least, I thank William LaMartin, PhD, whose competence and engagement allowed the presentation of my Darmstadt Colloquium Posters to exist in the form of the videos he created.

Karl Heinrich Hofmann