Hellmuth Stachel (born October 6, 1942 in

Graz Graz (; sl, Gradec) is the capital city of the Austrian state of Styria and second-largest city in Austria after Vienna. As of 1 January 2021, it had a population of 331,562 (294,236 of whom had principal-residence status). In 2018, the popul ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

) is an

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

, a Professor of Geometry at the

Technical University of Vienna TU Wien (TUW; german: Technische Universität Wien; still known in English as the Vienna University of Technology from 1975–2014) is one of the major universities in Vienna, Austria. The university finds high international and domestic recogn ...

, who is known due to his contributions to

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

kinematics Kinematics is a subfield of physics, developed in classical mechanics, that describes the Motion (physics), motion of points, Physical object, bodies (objects), and systems of bodies (groups of objects) without considering the forces that cause ...

and

computer-aided design Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve c ...

Biography

Hellmuth Stachel was born on October 6, 1942 in

to the family of primary school teachers. He graduated from an elementary school in Trofaiach and secondary school (gymnasium) in

Leoben Leoben () is a Styrian city in central Austria, located on the Mur river. With a population of about 25,000 it is a local industrial centre and hosts the University of Leoben, which specialises in mining. The Peace of Leoben, an armistice bet ...

. In 1965 he graduated from the

University of Graz The University of Graz (german: link=no, Karl-Franzens-Universität Graz, ), located in Graz, Austria, is the largest and oldest university in Styria, as well as the second-largest and second-oldest university in Austria. History The unive ...

and

Graz University of Technology Graz University of Technology (german: link=no, Technische Universität Graz, short ''TU Graz'') is one of five universities in Styria, Austria. It was founded in 1811 by Archduke John of Austria and is the oldest science and technology research ...

, obtaining a diploma of a school teacher in “

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

” and “ descriptive geometry.” As a Ph.D. student of Graz University he majored in “mathematics,

astronomy Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...

and

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...

.” His doctoral advisor was Professor Fritz Hohenberg. Hellmuth Stachel obtained his

doctorate A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism ''l ...

in 1969 from Graz University and passed thought

habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a ...

in 1971 at the Technical University of Graz. In 1980 he moved to the

Vienna University of Technology TU Wien (TUW; german: Technische Universität Wien; still known in English as the Vienna University of Technology from 1975–2014) is one of the major universities in Vienna, Austria. The university finds high international and domestic recogn ...

. Hellmuth Stachel held several visiting positions in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

: in August 1984 he was a visiting professor at

South China University of Technology The South China University of Technology (SCUT; ) is a public university in Guangzhou, Guangdong, China. The university is co-sponsored by the China Ministry of Education and the Guangdong Provincial People's Government. The university is a mul ...

Guangzhou Guangzhou (, ; ; or ; ), also known as Canton () and alternatively romanized as Kwongchow or Kwangchow, is the capital and largest city of Guangdong province in southern China. Located on the Pearl River about north-northwest of Hong Kon ...

and, in October 1989, at

Tongji University Tongji University () is a comprehensive public research university located in Shanghai. Established in 1907 by the German government together with German physicians in Shanghai, Tongji is one of the longest-standing, most selective, and most pr ...

Shanghai Shanghai (; , , Standard Mandarin pronunciation: ) is one of the four direct-administered municipalities of the People's Republic of China (PRC). The city is located on the southern estuary of the Yangtze River, with the Huangpu River flow ...

. Professor Stachel takes an active part in the work o
“International Society for Geometry and Graphics”
(ISGG). In 1990 he was elected a chairman and, in 1994, a vice-president of the society. In 1996 he has created the scientific journa
Journal for Geometry and Graphics
and since then serves it as the Editor-in-Chief.

Research

Hellmuth Stachel wrote 3 books (in cooperation with other scholars) and approximately 120 scientific articles on classical and descriptive

and the theory of mechanisms, as well as on computer aided design. He studied

flexible polyhedra In geometry, a flexible polyhedron is a polyhedral surface without any boundary edges, whose shape can be continuously changed while keeping the shapes of all of its faces unchanged. The Cauchy rigidity theorem shows that in dimension 3 such ...

in the 4-dimensional Euclidean space and 3-dimensional Lobachevsky space.

Awards and prizes

In 1991 Hellmuth Stachel was elected a corresponding member of the Austrian Academy of Sciences. In 1993 he received the “German-Austrian University-Software Award” for the development of educational Cad-3D programs. In 2004 he receive
The Steve M. Slaby Award
On November, 1st 2010 Hellmuth Stachel received an honorary doctorate from the

Dresden University of Technology TU Dresden (for german: Technische Universität Dresden, abbreviated as TUD and often wrongly translated as "Dresden University of Technology") is a public research university, the largest institute of higher education in the city of Dresden, th ...

Books

* G. Glaeser and H. Stachel. ''Open Geometry: OpenGL + Advanced Geometry''. Springer: New York, 1999, 392 p. . * T. Arens, F. Hettlich, Ch. Karpfinger, U. Kockelkorn, K. Lichtenegger, and H. Stachel. ''Mathematik'', 1.Aufl. Spektrum: Heidelberg, 2008, 1500 p. . * T. Arens, F. Hettlich, Ch. Karpfinger, U. Kockelkorn, K. Lichtenegger, and H. Stachel. ''Arbeitsbuch Mathematik''. Spektrum: Heidelberg, 2009, 683 p. . * G. Glaeser, H. Stachel and B. Odehnal. ''The Universe of Conics: From the ancient Greeks to 21st century developments''. Springer Spektrum: Heidelberg, 1st ed. 2016, 488 p. . * B. Odehnal, G. Glaeser and H. Stachel. ''The Universe of Quadrics''. Springer: NY, 1st ed. 2020, 600 p.

Articles on flexible polyhedra

* H. Stachel. ''Flexible octahedra in the hyperbolic space''. In the book: ''Non-Euclidean geometries. János Bolyai memorial volume'' (Eds. A. Prékopa et al.). New York: Springer. Mathematics and its Applications (Springer) 581, 209–225 (2006). . * H. Stachel. ''Flexible cross-polytopes in the Euclidean 4-space''. J. Geom. Graph. 4, No.2, 159–167 (2000). ISSN 1433-8157. * H. Stachel. ''Higher order flexibility of octahedra''. Period. Math. Hung. 39, No.1–3, 225–240 (1999). ISSN 0031-5303.

References