物理学史与哲学

We study a long-recognised but under-appreciated symmetry called "dynamical similarity" and illustrate its relevance to many important conceptual problems in fundamental physics. Dynamical similarities are general transformations of a…

Newton's rotating bucket pours cold water on the naive relationalist by vividly illustrating how certain rotational effects, particularly those due to non-zero angular momentum, can depend on more than just relations between material…

A physically consistent semi-classical treatment of black holes requires universality arguments to deal with the `trans-Planckian' problem where quantum spacetime effects appear to be amplified such that they undermine the entire…

In the paper we will describe three instruments of particular historical and didactic interest belonging to the Historical Collection of Physics Instruments of Palermo University: a convex mirror most likely dating back to the early…

I provide the backstory on how a historical error in the Feynman Lectures on Physics was corrected.

In the middle of the seventeenth century, Andr\'e Tacquet, S.J. briefly discussed a scientific argument regarding the structure of a Copernican universe, and commented on Galileo Galilei's discussion of that same argument -- Galileo's…

The question of what is real is familiar in physics. This paper addresses this question through the notions of reality in the models of of the world (schemata) that are created by the information gathering and utilizing systems (IGUSes) in…

Feza G\"ursey was a brilliant physicist who loved symmetries and beautiful mathematical structures such as group theory and division algebras. In this centenary year, I give a brief review of some of his contributions and then zero-in on…

Prominently, Norton (2008) argues against constructivism about spacetime theories, the doctrine that spatiotemporal structure in the dynamics only has derivative status. Among other things, he accuses Brown and Pooley's dynamical approach…

A long and intense debate in philosophy is concerned with the question whether there can be haecceistic differences between possible worlds, that is, nonqualitative differences that only arise from different de re representations. According…

The 100th anniversary of Bruno Touschek's birth also marks 60 years since the first beams of electrons and positrons circulated in AdA, the first ever matter-antimatter collider built in Frascati National Laboratories following Touschek's…

Enrico Fermi estimated the yield of the Trinity test to be about 10 kilotons by dropping small pieces of paper and observing their motion in the blast wave. This is about 40% of the radiochemically derived value of $25 \pm 2$ kilotons that…

Newton's First Law of Motion is typically understood to govern only the motion of force-free bodies. This paper argues on textual and conceptual grounds that it is in fact a stronger, more general principle. The First Law limits the extent…

This paper reviews briefly the history of the Michelson experiment, invented and performed for the first time in the Astrophysical Observatory Potsdam in 1881. The paper draws attention to the International Michelson Colloquium, held from…

In my opinion, nothing useful has ever been written on the question in the title, and small is the contribution that I have to offer. I outline an explanation for why there is something rather than nothing, an explanation which, however, I…

On November 23, 2021, the Einstein-Besso manuscript on the perihelion motion of Mercury will be auctioned at Christie's. Expected to fetch around $3M, it promises to be the most expensive scientific manuscript ever sold at auction. In this…

We present an English translation of Erwin Schr\"odinger's paper on "On the Reversal of the Laws of Nature". In this paper Schr\"odinger analyses the idea of time reversal of a diffusion process. Schr\"odinger's paper acted as a prominent…

The 1980s was a flourishing time for Cuban physics, with various achievements ranging from the design of several experiments to be performed by a Cuban cosmonaut in 1980, to the synthesis of the first superconductor with critical…

J{\'e}r{\^o}me Lalande, a famous French astronomer in the 18th century, collaborated throughout his career with several female calculators in astronomy: Nicole Reine Lepaute, Marie Louise Dupi{\'e}ry and Marie Jeanne Lefran{\c c}ois. Taking…

I give a brief review of the search for a proper definition of energy in General Relativity (GR), a far from trivial quest, which was only completed after four and a half decades. The equally (or perhaps more) difficult task of establishing…