With his exhibitions and the museum, the professor wants to correct what he sees as the wrong image of his subject: "Math is much too abstract in school and has little to do with the student's personality." The fabric is flogged without reference to it to give birth to the world. When treating symmetries, for example, one only needs to open the eyes of the children to symmetrical or asymmetrical things in their everyday lives. In the same way, examples of mathematical concepts such as order, chance or infinity could be found everywhere. "When we get the students excited about mathematics in this way, they suddenly do amazing things." Beutelspacher has already created a working group that develops educational materials for it.

The 50-year-old gushes with ideas about what the museum should see and touch: Lasers drawing geometric figures. Huge ball tracks, which demonstrate how a slope must be inclined so that the ball arrives as quickly as possible: first falling steeply, then flattening. Elsewhere visitors dip wire loops in soapy water. The resulting soap skins form so-called minimal surfaces, whose calculation mathematicians has been busy for a long time, "says the professor of geometry and discrete mathematics enthusiastically. A few steps further, according to Beutelspacher's ideas, encoded messages will be encoded, something that is particularly close to his heart: How texts can be encoded is examined in so-called cryptography.

Beutelspacher holds specially arranged lectures for children about this subfield of mathematics. He has already thrilled up to 300 eight- to twelve-year-olds at the same time. To a regular presentation of the manuscript is not to think, says the Giessener. "The first time I asked the rhetorical question, who knew a secret code, 50 arms jumped up." Of course he takes up the objections of the young listeners, even if that upsets his whole concept. "At the end of such an hour, I am completely sweaty, " confesses the professor, who is known for excessive gestures plus full-body use in lectures: "My wife always says I should not fidget like that." But his commitment brings him the sympathies of the kids, So he was already adopted with La Ola waves. Beutelspacher is likely to be the only German university teacher to whom the well-known from sports stadiums Sympathiewoge has ever been flown. As a young researcher at the University of Mainz, he started working on cryptography 20 years ago. At that time, the so-called public-key procedures had just been rediscovered. Today, public-key procedures protect e-mails from uninvited readers. Electronic payment systems depend on them. And the new UMTS standard for cell phones is also based on them. display

They allow encrypted communication without the partners having previously had confidential contact. Beutelspacher speaks of a revolution of thought. For in public-key method, the receiver can tell the sender an encryption code without any problems on a public line. The trick is that an eavesdropper can not reconstruct content from the encoded message. For this he would need a second key, which only the receiver has. Background of public-key procedures are mathematical tasks that are relatively simple in one direction, and incredibly difficult to solve in another. So computers do not have any difficulty completing primes - even if they have a hundred or more digits. On the other hand, examining such a product according to the original primes overwhelms even the fastest electron brain. For the practice this means: messages are encrypted with the number product. However, this can only be deciphered by someone who knows the individual factors of this number. With cryptography so far seemingly purely abstract mathematics has become a practical application - and Beutelspacher a job in industry. Actually, he never wanted to go to business. In an interview at Siemens, he just wanted to test just his market value: "But the offer was too tempting." In 1985, he begins to build the Department of Cryptography at the Munich-based electronics company. At the same time, he makes a new experience: "All of a sudden, people were interested in what I worked out." At the university, that was quite different: "It is already a sign of interest and recognition when a colleague mentions after years in a lecture : I could improve this theorem of Beutelspacher

His industrial work is practical: he is developing a procedure for electronic payment with chip cards and fulproof secure telephone cards. The first patent he receives for an innovative alarm system. But after only three years Beutelspacher takes on a call to the University of Gie en. "I have missed the courses." He has not given up the practice. He has good contacts to the economy until today.

Anyone who picks up German banknotes will be reminded of a bag of pouches: on each ticket there is a sequence of letters and numbers that can be used to identify the note. The last position is a test digit. They are used to detect errors such as when the digit sequence is incorrectly tapped or scanned. That was not enough for the Bundesbank. At the time of introduction of the new banknotes, the currency guarantors also wanted to identify the inadvertent exchange of two characters by the prefix number. Beutelspacher solved this task with flying colors: within a few days he found the suitable mathematics. "It has to do with the axes of symmetry of a regular pentagon, " he says, and is visibly pleased to be able to present proof of the practical relevance of mathematics that seems to be aloof can.

In order to counteract the image of his discipline as a dry, dustless art, the man does not stop at anything: For a photo session for the local newspaper he lay down in front of a geometric artificial stone on the street. When he exhibited his mathematics to touch Anf in a shopping center in Koblenz, he gave a lecture to bargain hunters about which many forgot his purchases. In a protest against bad study conditions, he should relocate his lecture in a public bus. Beutelspacher was only too happy to attack what other professors would have refused br sk. But instead of presenting the material as in the auditorium, he played theater in handful puppets in the battering bus. A raven and a devil debated about infinity. Fittingly, it was about the lack of space in lectures and seminars. "After all, I have proved a mathematical sentence in the puppet show, " smiles the Gie ener. Such actions and his numerous popular books prove: Beutelspacher, who now wants to try a crime thriller with a mathematical background, thinks of non-mathematicians, in order to gain a basic understanding To convey "the Queen of Science". "As a child, I was a contact-shy individual." After a parent's afternoon in the kindergarten, his mother was horrified because he had been playing away from the circle of children all the time. She had even worried that her son was disabled. Even as a student in his hometown T bingen he was still very introverted.

The big turn came when he was already 33 years old. Italian colleagues invited the young Mainz Professor Beutelspacher for a few weeks to an exchange of views in the Abruzzi: In the secluded university town of Laquila no one spoke English. "And my knowledge of Italian was just enough to order pizza." With hands and feet, it was finally possible to come to an understanding: "I was forced to leave The Italian way of life did the rest, to remove the stiffness: After a good lecture embrace one of the colleagues.

The talking, debating, discussing, the personal commitment of his Italian colleagues inflamed the Germans. He left the ivory tower in 1983 in Abruzzo and has never visited again. A year ago, the Gie ener published a popular science book about his aha experience in l'Aquila. "Pasta all'infinito" tells the story of the right way to eat spaghetti and the so-called projective levels that he was already working on in his diploma thesis.

Beutelspacher is a rare class in science. As a mathematician, he is virtually unique. Text: Dr. Wolfgang Blum; Photos: M. Dannenmann

compact born (5.6.1950) and raised in Tübingen In the kindergarten inconspicuous, yes obdurated 1981 temporary professorship (C2) for Discrete Mathematics in Mainz 1983 key experience in the Italian l'Aquila 1985 start of a three-year industrial career at Siemens 1988 chair in Giessen for geometry and Discrete Mathematics 1988 New check digit method for German banknotes 1995 Mathematics lectures for eight to twelve year olds 2001 Opening of the Mathematics Museum in Gießen's Main Customs Office

bdw community: 1) How to communicate with Beutelspacher? "Torture your professor, " demands Beutelspacher on the Internet (www.Mathematik). Anyone who wants can let off steam on a passport photo of the mathematician and pucker his face in the face. If there are still questions left, you will find extensive information on mathematics under Abs (Albrecht Beutelspachers) ABC under F for FAQ (frequently asked questions). If that's not enough, write to or snail-mail to Prof. Albrecht Beutelspacher, Mathematical Institute of the University of Gießen, Arndtstr. 3, 35392 casting. 2) Albrecht Beutelspacher: Pasta all'infinito - my Italian journey into mathematics, CH Beck, Munich 1999, 268 pages, DM 38, -. With much humor Beutelspacher describes his research stay in the Italian l'Aquila. It's not just about acclimatization and language problems. The conversations with his hosts and especially their children offer a deep insight into a common topic: What is infinity? The author entertainingly explains terms such as irrational numbers, golden ratio and exponential growth, and introduces readers to famous mathematicians such as Zeno and Aristotle. He remains very personal from the first to the last page.

3) Exhibition "Mathematics to touch"

01.06.-30.10.2000 Forum for Science and Technology, Göttingen 15.09.-03.12.2000 Hygiene-Museum, Dresden 18.09.-30.09.2000 Ricarda-Huch-Gymnasium, Gelsenkirchen 25.09.-27.09.2000 Math is top !, Duisburg 10.10 .-29.10.2000 Phänomenta, Flensburg Visitors do not have to crunch their brains over abstract formulas. Trying out and experimenting are in the foreground, be it with mirrors, soap bubbles, building blocks, three-dimensional puzzles, while walking through a function or on the computer. Mathematics can be experienced everywhere on its own (see www.math.de).

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