Some information about the scientific work of Professor Gross.

Great part of the scientific activity of Prof. Bernhard Gross which came before his studies on electrets receive very little attention but are priceless. The papers on electrets started to have international prominence and repercussion after the 70’s and continued until early 80’s. I will comment a little about what he produced since the beginning of his career until the 60’s.

While still in Stuttgart, Germany, he published some papers about latitude corrections in detectors used to study cosmic rays in the atmosphere [references 1 and 2]. These articles were published in German. His work was soon generalized by E. J. Williams and published by Nature magazine [3]. Later on, this correction became known as “Gross’s transformation”. In the celebrated book about cosmic rays, published in 1950 [4], chapter 3 is dedicated to “Gross’s transformation”.

His first paper in Brazil was regarding electrical properties of zeolites [5] which, together with the work on delayed effects on dielectric solids [6] and, later on, on static charges on dielectrics [7], marked the beginning of his research in the field of Materials, which would culminate with famed studies about electrets after the 60’s. However, some seminal works on mathematical models applied to visco-elastic systems were very significant. These works were published in the last years of the 40’s [8-11]. As a result of this works, Gross published a book on the subject, which is still used as essential reference for the field of rheology of solids [12].

Circa 1950, Gross performed a series of studies on the effects of radiation on vitreous and polymeric systems [13.14]. With these studies, he discovered an electrical current in dielectric solids, which was related to the Compton Effect, originating celebrated and seminal work [15]. This effect explained the phenomenon occurring in nuclear plants, which had remained unexplained until then. The glass windows used as protection to radiation spontaneously cracked after being used for some time. Gross was invited by the Radiation Research Center in New York and, together with local researchers, he proved that Compton currents were responsible for the degradation of glass [16]. Right after that, Gross invented the Compton dosimeter [17], which he patented in the Unites States, but lost it for the American army after a legal battle.

Still in Brazil, Gross started his first studies about electrets [18, 19]; being the first to manufacture what he called radioelectrets. After retiring from the National Institute of Technology, he was invited to be in charge of the Department of Scientific and Technical Information of the International Agency of Atomic Energy, in Vienna, where he stayed until the end of the 60’s. He published some relevant papers about scientific information [20] and returns as a researcher in the field of electrets in the 70’s.

Professor Roberto Mendonça Faria
Researcher on Group of Polymers “Prof. Bernhard Gross” (USP São Carlos)
Prof. Bernhard Gross’s PhD student, between 1980 and 1984.


[1] For the Pressure Dependence of the Ionization by Cosmic Ray (Zur Druckabhängigkeit der Ionisation durch. Ultrastrahlung), B. Gross, ZEITSCHRIFT FUR PHYSIK Volume: 78 Issue: 3-4 Pages: 271-278 DOI: 10.1007/BF01337596 Published: MAR 1932.
[2] For the absorption of the ultra radiation (Zur Absorption der Ultrastrahlung), ZEITSCHRIFT FUR PHYSIK, B. Gross,  Volume: 83 Issue: 3-4 Pages: 214-221 DOI: 10.1007/BF01331141 Published: MAR 1933.
[3] Spectrum and latitude variation of penetrating radiation, E. J. Williams, Nature, 512 (1933).
[4] Cosmic rays, L. Janossy (1950), Oxford at Clarendon Press.
[5] On the electric conductivity of Zeolite, B. Gross, ZEITSCHRIFT FUR KRISTALLOGRAPHIE Volume: 92 Issue: 3/4 Pages: 284-292 Published: DEC 19.
[6] On after-effects in solid dielectrics, B. Gross, PHYSICAL REVIEW Volume: 57 Issue: 1 Pages: 57-59 DOI: 10.1103/PhysRev.57.57 Published: JAN 1940.
[7] STATIC CHARGES ON DIELECTRICS, B. Gross, BRITISH JOURNAL OF APPLIED PHYSICS Volume: 1 Issue: OCT Pages: 259-267 DOI: 10.1088/0508-3443/1/10/304 Published: 1950.
[8] ON CREEP AND RELAXATION, B. Gross, PHYSICAL REVIEW Volume: 71 Issue: 2 Pages: 144-144 Published: 1947.
[9] ON CREEP AND RELAXATION, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 18 Issue: 2 Pages: 212-221 DOI: 10.1063/1.1697606 Published: 1947.
[10] ON CREEP AND RELAXATION .2, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 19 Issue: 3 Pages: 257-264 DOI: 10.1063/1.1715055 Published: 1948.
[11] FRICTIONAL LOSS IN VISCO-ELASTIC SUBSTANCES, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 21 Issue: 2 Pages: 185-185 DOI: 10.1063/1.1699622 Published: 1950.
[12] Mathematical structure of the theories of Viscoelasticity, B. Gross, Paris, Hermann Press (1953).
[13] IRRADIATION EFFECTS IN BOROSILICATE GLASS, B. Gross, PHYSICAL REVIEW Volume: 107 Issue: 2 Pages: 368-373 DOI: 10.1103/PhysRev.107.368 Published: 1957.
[14] IRRADIATION EFFECTS IN PLEXIGLAS, B. Gross, JOURNAL OF POLYMER SCIENCE Volume: 27 Issue: 115 Pages: 135-143 DOI: 10.1002/pol.1958.1202711511 Published: 1958.
[15] THE COMPTON CURRENT, B. Gross, ZEITSCHRIFT FUR PHYSIK Volume: 155 Issue: 4 Pages: 479-487 DOI: 10.1007/BF01333129 Published: 1959.
[16] BETA-PARTICLE TRANSMISSION CURRENTS IN SOLID DIELECTRICS, B. Gross, A. Bradley & A. P. Pinkerton, JOURNAL OF APPLIED PHYSICS Volume: 31 Issue: 6 Pages: 1035-1037 DOI: 10.1063/1.1735740 Published: 1960.
[17] Compton Dosimeter for measurements of penetrating x-rays and gamma rays, B. Gross, RADIATION RESEARCH Volume: 14 Issue: 2 Pages: 117-& DOI: 10.2307/3570883 Published: 1961.
[18] GAMMA IRRADIATION EFFECTS ON ELECTRETS, B. Gross & R. J. D. Moraes, PHYSICAL REVIEW Volume: 126 Issue: 3 Pages: 930-& DOI: 10.1103/PhysRev.126.930 Published: 1962.
[19] POLARIZATION OF ELECTRET, B. Gross & R. J. D. Moraes, JOURNAL OF CHEMICAL PHYSICS Volume: 37 Issue: 4 Pages: 710-& DOI: 10.1063/1.1733151 Published: 1962.