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Hans Grassmann (* 21. May 1960 in Bamberg) is a German physicist who teaches and works in Italy. Grassmann is author of 4 books and more then 250 scientific publications, and is founder and director of the spin-off company Isomorph srl. His major contributions to physics are: the development of a CsI(Tl) calorimeter with photodiode readout, the W-charge asymmetry analysis, his contribution to the discovery of the top quark, the development of a physics theory of information, a new physics approach in the understanding of shrouded turbines and the development of a simple concentrating mirror system (“linear mirror”).

Life and Work

Career

Hans Grassmann studierte Physik an der Universität Erlangen. Für seine Diplomarbeit entwickelte er zusammen mit seinem Betreuer Eckart Lorenz (MPI München) ein Kalorimeter aus Cäsumiodid-Thallium-Kristallen, das bereits bei einigen physikalischen Experimenten, u. a. am CERN, verwendet wurde.

1984 wurde Grassmann Mitglied der Forschergruppe um Carlo Rubbia am europäischen Kernforschungszentrum CERN in Genf. Im selben Jahr promoviert er über seine Suche nach Leptoquarks ("Limits on Leptoquarks from missing energy and from muon events at the ppbar collider").

Study of physics

From 1979 to 1984 Grassmann studied physics at the Universities of Erlangen and Hamburg. For his laurea thesis he develops together with his supervisor E.Lorenz (MPI Munich) a new method for the calorimetric detection of high energy photons, based on the use of scintillating crystals (CsI(Tl)) with photodiode readout. Some of the most advanced scientific experiments have by now made use on this technology, for instance the Crystal-Barrel, the BaBar, the CLEO and the Belle experiments and the satellite Glast.

From 1984 to 1988 Grassmann was part of the experiment UA1 headed by Carlo Rubbia at the European centre for nuclear research CERN (Geneva), where he wrote his PhD thesis with H.Faissner (RWTH Aachen).

From 1987 to 1999 Grassmann was part of the CDF collaboration (Fermilab, Chicago) at the Tevatron collider, also working with the SSC lab (Super conducting Super Collider Laboratory) at Dallas. In 1988 he developed with his student S. Leone the study of the asymmetry in the production and decay of the W-boson at the Tevatron proton-antiproton collider. At the Tevatron W particles are predominantly produced in collisions of valence quarks. Therefore one can determine the kinematic properties of the u- and d quarks (in the proton and antiproton) from the observation of W production. Furthermore, by analysing only the relative difference in the production of W+ and W- particles, one can substantially reduce the effects of systematic uncertainties in the experimental device. In the following years Grassmann developed a new method for detecting the top quark. The method makes use of the different kinematic properties of production and decay of top quark particles and of background events (like for instance the production of W particles together with hadronic jets). In 1994 this analysis was successfully applied by Grassmann, G. Bellettini and M. Cobal and the top quark was observed in the data of the Tevatron collider. Later, the analysis was repeated on a larger data sample, confirming the results obtained in 1994.

After the top discovery Grassmann began to work on a connection between the classic theory of information (Shannon, Chaitin, Kolmogorv et al.) and physics. From the work done by Szilard (and also Landauer and Bennet) it is known, that there must be some sort of connection between physics and information theory, because storing or deleting one bit of information is in certain situations dissipating energy. In spite of this fact neither classic information theory nor algorithmic information theory contain any physics variables ( the variable “entropy” used in information theory is not a state function and is therefore not the thermodynamic entropy used in physics). Grassmann tried to make use of existing and established concepts like “message”, “amount of information” or “complexity”, but setting them into a new mathematical frame work: his approach is based on vector algebra or on Boolean algebra instead of probability theory.

In parallel to these studies he develops a new physics approach for studying shrouded wind turbines. These studies are successful from a scientific point of view, and create several publications, but they do not directly lead to a new product due to a lack of funding.

Enterprenurship

The spin off company Isomorph focused instead on the development of an innovative concentrating mirror system aimed at making a more economic use of solar energy. Since the system is very simple, it would be cheap to produce. This “linear mirror” system received its first recognition from the Italian Physical Society in October 2008, when A. Prest, a collaborator of Isomorph won a price for his presentation of the linear mirror. The device became operational in autumn of 2008 and performed according to theoretical predictions. In 2004 the spin off company Isomorph srl is founded. From an economic point of view Isomorph has the mission to create new scientific concepts, procedures and devices, based on physics research and to sell those. From a scientific point of view Isomorph represents an attempt to make free research possible – research independent of the scientific-administrative complex.

Books

In books and newspaper articles Grassmann tries to explain physics to the general public. “Everybody can understand physics. What cannot be understood is not physics.” Each book is also dealing with some particular aspect of the relation between science and society. The books are also available in several translations.

• Grassmann, H.: Das Top Quark, Picasso und Mercedes Benz – oder Was ist Physik?, Rowohlt Berlin, 1997, ISBN 3-87134-328-5.
• Grassmann, H.: Alles Quark? Ein Physikbuch, Rowohlt Berlin, Berlin, 2000, ISBN 3-87134-362-5.
• Grassmann, H.: Das Denken und seine Zukunft – von der Eigenart des Menschen, Hoffman und Campe, Hamburg, 2001, ISBN 3-455-09333-7.
• Grassmann, H.: Ahnung von der Materie – Physik für alle., Dumont, 2008, ISBN 978-3832180829.

Weblinks

• Kurze Biografie
• Universität Udine (Italienisch)
• Contributions to physics (engl.)