Physics - History of Physics Publications (50)

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Physics - History of Physics Publications

Subject of this article is the relationship between modern cosmology and fundamental physics, in particular general relativity as a theory of gravity on one side, together with its unique application in cosmology, and the formation of structures and their statistics on the other. It summarises arguments for the formulation for a metric theory of gravity and the uniqueness of the construction of general relativity. It discusses symmetry arguments in the construction of Friedmann-Lema\^itre cosmologies as well as assumptions in relation to the presence of dark matter, when adopting general relativity as the gravitational theory. Read More


The very humble origins of the Cyberspace, and all the related developments that smoothly conspired and converged towards this concept, making its emergence possible, as the personal computer, TEX and LATEX, the Fax, the internet, the cellphone, and the World Wide Web, are discussed, always from a personal perspective. A separate, comprehensive explanation of the reasons for the appearance and subsequent evolution of each of these different phenomena, with explicit assessments and a future prospective of the main subject, is presented. Read More


In 1615 Paolo A. Foscarini, a Carmelite monk lived in a monastery of south Italy near Cosenza (Calabria), published a Trattato which, at variance to what was common at the time, has not been written in Latin, but in volgare, the ancient Italian language. We are currently investigating the Trattato, and we found strong evidences that, hidden in the Italian language of early seventeenth century, it represents, to our knowledge, the first systematic attempt to interpret something unknown at that time, as meteo-climate changes and their forecasting, in the scientific framework of environmental physical effects related to Sun-Atmosphere relationships. Read More


A personal recollection of events that preceded the construction of Supergravity and of some subsequent developments. Read More


Inspired by possible connections between gravity and foundational question in quantum theory, we consider an approach for the adaptation of objective collapse models to a general relativistic context. We apply these ideas to a list of open problems in cosmology and quantum gravity, such as the emergence of seeds of cosmic structure, the black hole information issue, the problem of time in quantum gravity and, in a more speculative manner, to the nature of dark energy and the origin of the very special initial state of the universe. We conclude that objective collapse models offer a rather promising path to deal with all of these issues. Read More


2017Jan
Affiliations: 1Laboratoire d'Astrophysique de Marseille, Centre de Physique Théorique, Observatoire de Paris

We discuss the reception of Copernican astronomy by the Proven\c{c}al humanists of the XVIth-XVIIth centuries, beginning with Michel de Montaigne who was the first to recognize the potential scientific and philosophical revolution represented by heliocentrism. Then we describe how, after Kepler's Astronomia Nova of 1609 and the first telescopic observations by Galileo, it was in the south of France that the New Astronomy found its main promotors with the humanists and "amateurs \'eclair\'es", Nicolas-Claude Fabri de Peiresc and Pierre Gassendi. The professional astronomer Jean-Dominique Cassini, also from Provence, would later elevate the field to new heights in Paris. Read More


In the article, we will report on the recovery of a Melloni's optical bench built at the end of 1800 by the "macchinista" Filippo Caliri in the "belle \'epoque" of Palermo. A scientific instrument of particular historical and didactic interest belonging to the collection of Liceo Classico Statale "Umberto I" of Palermo. In the article, we will discuss the technical aspects of the interventions carried out. Read More


2017Jan
Affiliations: 1Astrophysics Department, French Alternative Energies and Atomic Energy Commission

In 1965, the discovery of a new type of uniform radiation, located between radiowaves and infrared light, was accidental. Known today as Cosmic Microwave background (CMB), this diffuse radiation is commonly interpreted as a fossil light released in an early hot and dense universe and constitutes today the main 'pilar' of the big bang cosmology. Considerable efforts have been devoted to derive fundamental cosmological parameters from the characteristics of this radiation that led to a surprising universe that is shaped by at least three major unknown components: inflation, dark matter and dark energy. Read More


Strangeness signature of of quark-gluon plasma (QGP) is central to the exploration of baryon-dense matter: the search for the critical point and onset of deconfinement. In this lecture the discovery of QGP by means of strangeness is described. Several historical figures and their roles in this quest are introduced, and their roles delimited. Read More


Evaluating theories in physics used to be easy. Our theories provided very distinct predictions. Experimental accuracy was so small that worrying about epistemological problems was not necessary. Read More


I had the marvelous good fortune to be Ken Wilson's graduate student at the Physics Department, Cornell University, from 1972 to 1976. In this article, I present some recollections of how this came about, my interactions with Ken, and Cornell during this period; and acknowledge my debt to Ken, and to John Wilkins and Michael Fisher, who I was privileged to have as my main mentors at Cornell. I end with some thoughts on the challenges of reforming education, a subject that was one of Ken's major preoccupations in the second half of his professional life. Read More


This short exposition starts with a brief discussion of situation before the completion of special relativity (Le Verrier's discovery of the Mercury perihelion advance anomaly, Michelson-Morley experiment, E\"otv\"os experiment, Newcomb's improved observation of Mercury perihelion advance, the proposals of various new gravity theories and the development of tensor analysis and differential geometry) and accounts for the main conceptual developments leading to the completion of the general relativity: gravity has finite velocity of propagation; energy also gravitates; Einstein proposed his equivalence principle and deduced the gravitational redshift; Minkowski formulated the special relativity in 4-dimantional spacetime and derived the 4-dimensional electromagnetic stress-energy tensor; Einstein derived the gravitational deflection from his equivalence principle; Laue extended the Minkowski's method of constructing electromagnetic stress-energy tensor to stressed bodies, dust and relativistic fluids; Abraham, Einstein, and Nordstr\"om proposed their versions of scalar theories of gravity in 1911-13; Einstein and Grossmann first used metric as the basic gravitational entity and proposed a "tensor" theory of gravity (the "Entwurf" theory, 1913); Einstein proposed a theory of gravity with Ricci tensor proportional to stress-energy tensor (1915); Einstein, based on 1913 Besso-Einstein collaboration, correctly derived the relativistic perihelion advance formula of his new theory which agreed with observation (1915); Hilbert discovered the Lagrangian for electromagnetic stress-energy tensor and the Lagrangian for the gravitational field (1915), and stated the Hilbert variational principle; Einstein equation of general relativity was proposed (1915); Einstein published his foundation paper (1916). Read More


The Astronomy Genealogy Project ("AstroGen"), a project of the Historical Astronomy Division of the American Astronomical Society (AAS), will soon appear on the AAS website. Ultimately, it will list the world's astronomers with their highest degrees, theses for those who wrote them, academic advisors (supervisors), universities, and links to the astronomers or their obituaries, their theses when on-line, and more. At present the AstroGen team is working on those who earned doctorates with astronomy-related theses. Read More


It is argued that if the non-unitary measurement transition, as codified by Von Neumann, is a real physical process, then the "probability assumption" needed to derive the Second Law of Thermodynamics naturally enters at that point. The existence of a real, indeterministic physical process underlying the measurement transition would therefore provide an ontological basis for Boltzmann's Stosszahlansatz and thereby explain the unidirectional increase of entropy against a backdrop of otherwise time-reversible laws. It is noted that the Transactional Interpretation (TI) of quantum mechanics provides such a physical account of the non-unitary measurement transition, and TI is brought to bear in finding a physically complete, non-ad hoc grounding for the Second Law. Read More


Previously, the most prominent explanation for the Star of Bethlehem was to identify one of many astronomical events in the sky as being the inspiration for the trip of the Magi. However, all the astronomical answers have detailed refutations, and general disproofs, so all the astronomical answers for the Star are dead. In 1999, Michael Molnar put forth a completely new solution, where the Star originated as a report of a natal horoscope for 17 April 6 BC. Read More


Quantum nonlocality is now used in many quantum information applications and it is important to analyze it both quantitatively and conceptually. In the present paper, we consider violation of multipartite Bell inequalities via the general local probability model - the LqHV (local quasi hidden variable) model [Loubenets, J. Math. Read More


The mausoleums of the emperors and of some members of the royal family of the Western Han Chinese dynasty, popularly known as Chinese pyramids, are a spectacular ensemble of tombs covered by a huge earth mounds, spread in the outskirts of modern Xian. Their inspiring model is the world famous tomb of the first emperor Qin, who reigned immediately before the Han, and in turn they were of inspiration for the much later mausoleums of the Song dynasty. Using satellite data we investigate here on cognitive aspects of the project of these two groups of monuments, with particular attention to the problem of their orientation and of their placement in the landscape; in particular, the presence of two distinct patterns of orientation, both connected with the polar region of the sky, arises. Read More


In this article, halfway between popularized exposition and historical account, some key moments in the development of atomic theory in its beginnings are discussed. In particular, the events and the major discoveries that have highlighted the discrete structure of the atom's energy levels are presented in their logical and chronological sequence, starting from early studies on the decomposition of light by prisms until the quantum theory. --- In questo articolo, a met\`a strada tra l'esposizione divulgativa e il resoconto storico, vengono affrontati alcuni momenti significativi dello sviluppo della teoria atomica ai suoi primordi. Read More


The article presents the results of the study of petroglyphs on a unique stone slab discovered near the kurgan 1 of the kurgan field Varvarinsky I (Rostov Oblast, Russia). Analysis of features of the location and style of petroglyph "tree" showed that the branches could determine semi-minor semiaxes m of the "dial" ellipses of analemmatic sundials with semi-major axis M = 24.2 cm for medium and high (northern) latitudes up to the North Pole and "tree" marks the direction to the North. Read More


The article presents the results of a study of petroglyphs on a unique stone slab discovered near the kurgan 1 of the kurgan field Varvarinsky I (Rostov Oblast, Russia). During the study was done comparing it with plates of Srubna burials on which were depicted the petroglyphs. Similar features for all the considered slabs are elliptically arranged wells. Read More


The process of doing Science in condition of uncertainty is illustrated with a toy experiment in which the inferential and the forecasting aspects are both present. The fundamental aspects of probabilistic reasoning, also relevant in real life applications, arise quite naturally and the resulting discussion among non-ideologized, free-minded people offers an opportunity for clarifications. Read More


The ancient priest-astronomers constantly watched many heavenly bodies. The record about Halley's Comet of 1682 A.D. Read More


Recent studies of radioisotopes in tree rings or ice cores suggest that extreme space weather events occurred in the pre-telescope age. Observational records of naked-eye sunspots and low-latitude auroras in historical documents in pre-telescopic age can provide useful information on past solar activity. In this paper, we present the results of a comprehensive survey of records of sunspots and auroras in Chinese official histories from the 6th century to the 10th century, in the period of Su\'i, T\'ang, the Five Dynasties and Ten Kingdoms. Read More


A translation of Paul Ehrenfest's 1933 paper, entitled "Phase transitions in the usual and generalized sense, classified according to the singularities of the thermodynamic potential" is presented. Some historical commentary about the paper's context is also given. Read More


This paper celebrates the remarkable life, science and legacy of Abb\'e Georges Lema\^itre, the Belgian cleric and professor of physics; he was the architect of the fireworks model for the origin of the universe. He died half a century ago, three days after learning that Arno Penzias and Robert Wilson had discovered the cosmic microwave background. Despite being gravely ill from leukaemia, Lema\^itre lucidly praised this news, which confirmed the explosive genesis of our universe. Read More


This work is a conceptual analysis of certain recent developments in the mathematical foundations of Classical and Quantum Mechanics which have allowed to formulate both theories in a common language. From the algebraic point of view, the set of observables of a physical system, be it classical or quantum, is described by a \emph{Jordan-Lie algebra}. From the geometric point of view, the space of states of any system is described by a \emph{uniform Poisson space with transition probability}. Read More


Classes started in the newly established Physics Department of Calcutta University Science College in 1916. Raman, Bose and Saha were three young members of the small physics faculty consisting of barely half a dozen faculty members. Within about one decade, three extraordinary discoveries came from these young men---Saha ionization equation in 1920, Bose statistics in 1924, Raman effect in 1928. Read More


Einstein wrote memorably that `The eternally incomprehensible thing about the world is its comprehensibility.' This paper argues that the universe must be comprehensible at some level for information gathering and utilizing subsystems such as human observers to evolve and function. Read More


I review Stanley Mandelstam's many contributions to particle physics, quantum field theory and string theory covering the years 1955 through 1980. His more recent work will be reviewed by Nathan Berkovits. This is my contribution to the Memorial Volume for Stanley Mandelstam (World Scientific, 2017). Read More


The claim of the freedom of the will (understood as an individual who is transcendent to Nature) in the name of XXth century scientific knowledge, against the perspective of XVIIIth-XIXth century scientific materialism, is analysed and refuted in the present paper. The hypothesis of reductionism finds no obstacle within contemporary natural sciences. Determinism in classical physics is irrefutable, unless classical physics is itself refuted. Read More


The genesis of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) after German re-unification as described here, shows that the history of the founding of the institute is not as simplistic as claimed e.g., in the presentation by the institute. Read More


Recently, a significant carbon-14 enhancement in the year 994 in tree rings has been found, suggesting an extremely large cosmic ray flux event during a short period. The origin of this particular cosmic ray event has not been confirmed, but one possibility is that it is of solar origin. Contemporary historical records of low latitude auroras can be used as supporting evidence for intense solar activity around that time. Read More


Even though quantum mechanics has existed for almost 100 years, questions concerning the foundation and interpretation of the theory still remain. These issues have gathered more attention in recent years, but does this mean that physicists are more aware of foundational issues concerning quantum mechanics? A survey was sent out to 1234 physicists affiliated to 8 different universities. 149 responded to the questions, which both concerned foundational issues related to quantum mechanics, specifically, as well as questions concerning interpretations of physical theories in general. Read More


In quantum gravity space and time lose their status as fundamental parts of the physical reality. However, according to Kant, space and time are the a priori conditions of our experience. Does Kantian characterization of these notions give constraints to quantum gravity, or does quantum gravity make Kantian characterization of space and time an invalid approach? This paper provides answers to these questions with a philosophical approach to quantum gravity. Read More


After some personal recollectioms about Rudolf Haag and his thoughts which led him to "Local Quantum Physics", the present work recalls his ideas about scattering theory, the relation between local observables and localized fields and his contributions to the physical aspects of modular operator theory which paved the way for an intrisic understanding of quantum causal localization in which fields "coordinatize" the local algebras. The paper ends with the presentation of string-local fields whose construction and use in a new renormalization theory for higher spin fields is part of an ongoing reformulation of gauge theory in the conceptual setting of Haag's LQP. Read More


The role of hyperlogarithms and multiple zeta values (and their generalizations) in Feynman amplitudes is being gradually recognized since the mid 1990's. The present lecture provides a concise introduction to a fast developing subject that attracts the interests of a wide range of specialists - from number theorists to particle physicists. Read More


Recalling the state of the art in the interpretation of quantum physics, this paper emphasizes that one cannot simply add a collapse parameter to the Schr\~A{\P}dinger equation in order to solve the measurement problem. If one does so, one is also committed to a primitive ontology of a configuration of matter in physical space in order to have something in the ontology that constitutes the determinate measurement outcomes. The paper then argues that in the light of this consequence, the collapse postulate loses its attractiveness in comparison to an ontology of persisting particles moving on continuous trajectories according to a deterministic law. Read More


We give a brief historical account on microscopic explanations of electrical conduction. One aim of this short review is to show that Thermodynamics is fundamental to the theoretical understanding of the phenomenon. We discuss how the 2nd law, implemented in the scope of Quantum Statistical Mechanics, can be naturally used to give mathematical sense to conductivity of very general quantum many-body models. Read More


The paper gives a historical survey of the causal position space renormalization with a special attention to the role of Raymond Stora in the development of this subject. Renormalization is reduced to subtracting the pole term in analytically regularized primitively divergent Feynman amplitudes. The identification of residues with "quantum periods" and their relation to recent developments in number theory are emphasized. Read More


One of the most important philosophers in the history, the German Friedrich Nietzsche, is almost ignored by physicists. The author who stated the death of God in 19th century was a science enthusiast, mainly during the second part of his work. With the aid of the physical concept of force, Nietzsche created his concept of will to power. Read More


Watchings of Canopus as a herald of the winter were important duties of ancient priests-astronomers on Easter Island. All the analysed data witness that this star was observed during the first and second voyages from Mangareva to the island. The names of king Hotu-Matua (Anua-Motua) and his father Tara tahi have been decoded. Read More


Claude Francis Milliet Dechales described the Coriolis effect in his 1674 Cursus seu Mundus Mathematicus. Dechales discussed and illustrated the deflection of both falling bodies and of projectiles launched toward the poles that should occur on a rotating Earth. Interestingly, this was done as an argument against the Earth's rotation, the deflections not having been observed at the time. Read More


I give a short commentary on a seminal article by T W B Kibble in 1976, "Topology of cosmic domains and strings". Read More


The article discusses foundations of the modern philosophy of physics and their transformations via development of the images of time. The author proves six main theses. (1) An analysis of relations between scientific knowledge and the nature of time visualizes the foundations of contemporary philosophy of physics. Read More


In a recent manuscript published in the Arxives (arXiv:1610.03049v1), it is claimed that it should be more appropriate to refer to the equation of hydrostatic equilibrium in a static spherically symmetric spacetime, supported by an isotropic perfect fluid, as the "Oppenheimer-Volkoff (OV) equation", instead of the "Tolman-Oppenheimer-Volkoff (TOV)", as is frequently done. As we shall see in this brief note, such a claim is not supported by the existing bibliography. Read More


This is a philosophical paper. It claims that there is a gap to be filled in the relationship between complexity theory (CT) and quantum theory (QT). This gap concerns two very distinct understandings of time. Read More


The Astronomical Diaries from Babylonia (ADB) are an excellent source of information of natural phenomena, including astronomical ones, in pre-Christ era because it contains the record of highly continuous and systematic observations. In this article we present results of a survey of aurora-like phenomena in ADB, spanning from BCE 652 to BCE 61. We have found 9 records of aurora-like phenomena. Read More


Contrary to counterfactual definiteness quantum theory teaches us that measuring instruments are not passively reading predetermined values of physical observables. Counterfactual definiteness allows proving Bell inequalities. If the contextual character of quantum measurements is correctly taken into account the proofs of these inequalities may not be done. Read More


This Introduction opens the book {\sl Standing Together in Troubled Times} which presents a story of friendship between Wolfgang Pauli, one of the greatest theoretical physicists of the 20th century, and Charlotte Houtermans. They met at the very onset of the quantum era, in the late 1920s in Germany where Charlotte was a physics student at G\"ottingen University. At that time G\"ottingen was right at the heart of groundbreaking developments in physics. Read More