History and Philosophy of Physics
On the basis of his `Z\"urich Notebook' I shall describe a particularly fruitful phase in Einstein's struggle on the way to general relativity. These research notes are an extremely illuminating source for understanding Einstein's main…
This article is about early roots of supersymmetry, as found in the literature from 1940s and early 1950s. There were models where the power of "partners" in alleviating divergences in quantum field theory was recognized. However, other…
Newton's Principia, when it appeared in 1687, was received with the greatest admiration, not only by the foremost mathematicians and astronomers in Europe, but also by philosophers like Voltaire and Locke and by members of the educated…
The relationship between inner and outer time is discussed. Inner time is intrinsically future directed and possesses the quality of a distinguished "now". Both of these qualities get lost in the operationalized external physical time,…
In this paper I argue that entanglement is a necessary component for any explanation of quantum speedup and I address some purported counter-examples that some claim show that the contrary is true. In particular, I address Biham et al.'s…
Abdus Salam's correspondence during his time as Director of the International Centre for Theoretical Physics (ICTP) is held in the Abdus Salam Archive of the Salam International Centre for Theoretical Physics+. I use this correspondence to…
I present a discussion of some open issues in the philosophy of space-time theories. Emphasis is put on the ontological nature of space and time, the relation between determinism and predictability, the origin of irreversible processes in…
Is presentism compatible with relativity ? This question has been much debated since the argument first proposed by Rietdijk and Putnam. The goal of this text is to study the implications of relativity and quantum mechanics on presentism,…
This article gives a brief outline of the life and works of the Austrian physicist Bruno Touschek, who conceived, proposed and, 50 years ago, brought to completion the construction of AdA, the first electron-positron storage ring. The…
As a tribute to our teacher and mentor on the occasion of his centennial celebration, we provide a brief historical overview and a summary of sustained interest in the topic of interaction of neutrons with alpha particles.
I write about H\'ector, his contributions to the early work in the quark model, and a general discussion of quantum statistics
The discovery of cosmic rays, a milestone in science, comprised scientists in Europe and the US and took place during a period characterised by nationalism and lack of communication. Many scientists that took part in this research a century…
At the end of the 17th century, the collection was established through the acquisition of Leiden instrumentmaker Musschenbroek's collection. Its aim was to demonstrate physical phenomena. Until the end of the 18th century, the collection…
Christian Ludwig Gerling's 1817 appointment as Professor for Mathematics, Physics and Astronomy resulted in the foundation of the Mathematical and Physical Institute of the Philipps University. In 1838, Gerling moved onto new premises in…
In 1785 astronomer William Herschel mapped out the shape of the Milky Way star system using measurements he called "star-gages." Herschel's star-gage method is described in detail, with particular attention given to the assumptions on which…
Ptolemy-s planetary model is an ancient geocentric astronomical model, describing the observed motion of the Sun and the planets. Ptolemy accounted for the deviations of planetary orbits from perfect circles by introducing two small and…
Although the extragalactic nature of quasars was discussed as early as 1960, it was rejected largely because of preconceived ideas about what appeared to be an unrealistically high radio and optical luminosity. Following the 1962…
A review is presented of the origin and development of the atomic hypothesis from antiquity till about the first millennium of the common era.
Aboriginal stories dating back many thousands of years talk of a fire from the sky in an area now home to the Henbury meteorite craters, in the Northern Territory
Are symmetries discovered or rather invented by humans ? The stand you may take firmly here reveals a lot of your epistemological position. Conversely, the arguments you may forge for answering to this question, or to one of its numerous…