"Sir Hermann Bondi, NatureThe late S. Chandrasekhar was best known for his discovery of the upper limit to the mass of a white dwarf star, for which he received ...

Newton's Philosophiae Naturalis Principia Mathematica provides a coherent and deductive presentation of his discovery of the universal law of gravitation. It is very much more than a demonstration that 'to us it is enough that gravity really does exist and act according to the laws which we have explained and abundantly serves to account for all the motions of the celestial bodies and the sea'. It is important to us as a model of all mathematical physics.Representing a decade's work from (...) a distinguished physicist, this is the first comprehensive analysis of Newton's Principia without recourse to secondary sources. Professor Chandrasekhar analyses some 150 propositions which form a direct chain leading to Newton's formulation of his universal law of gravitation. In each case, Newton's proofs are arranged in a linear sequence of equations and arguments, avoiding the need to unravel the necessarily convoluted style of Newton's connected prose. In almost every case, a modern version of the proofs is given to bring into sharp focus the beauty, clarity, and breath-taking economy of Newton's methods.Subrahmanyan Chandrasekhar is one of the most reknowned scientists of the twentieth century, whose career spanned over 60 years. Born in India, educated at the University of Cambridge in England, he served as Emeritus Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics at the University of Chicago, where he has was based from 1937 until his death in 1996. His early research into the evolution of stars is now a cornerstone of modern astrophysics, and earned him the Nobel Prize for Physics in 1983. Later work into gravitational interactions between stars, the properties of fluids, magnetic fields, equilibrium ellipsoids, and black holes has earned him awards throughout the world, including the Gold Medal from the Royal Astronomical Society in London, the National Medal of Science in the United States, and the Copley Medal from the Royal Society. His many publications include Radiative transfer, Hydrodynamic and hydromagnetic stability, and The mathematical theory of black holes, each being praised for its breadth and clarity. Newton's Principia for the common reader is the result of Professor Chandrasekhar's profound admiration for a scientist whose work he believed is unsurpassed, and unsurpassable. (shrink)

According to the Rayleigh criterion of classical optics, the finite resolving power of a microscope is due to the width of the central peak of the Fraunhofer diffraction pattern produced by the microscope's finite lens aperture. During the last few decades, theories and techniques for superresolution beyond the Rayleigh criterion have been developed in classical optics. Thus, Heisenberg's microscope could also in principle be made to give superresolution and thereby appear to violate the uncertainty relation. We believe that this paradox (...) is due to the inappropriate use of a definition, based purely on experimental convenience, to support a quantum mechanical theorem. (shrink)

About the Book : Several years ago, on a fateful night in a colonial house in Yercaud, Tamil Nadu, UG Krishnamurthi made a bonfire of Chandrasekhar's dreams.

Summary The 1935 conflict on the nature of relativistic degeneracy that pitted Subrahmanyan Chandrasekhar against Arthur Stanley Eddington is part of astronomical lore. In recountings of the events surrounding the dispute, the complaint is frequently aired that Chandrasekhar, who faced the pre-eminent astrophysicist of his time, did not enjoy the support of the astronomical community, which opted to side instead with Eddington. We reconsider these statements in the light of the published record and argue that the reception of (...) Chandrasekhar's ideas was, if anything, rather favourable and that any perceived lack of support may have been due in great part to the inability to distinguish, on an observational basis, between the predictions of the competing theories. We further argue that the observational situation improved little over the subsequent thirty years, but that this did not prevent Chandrasekhar's version of relativistic degeneracy, and associated theory of electron-degenerate stars, from gaining a central position within the realm of stellar structure and evolution. We briefly compare this status to that enjoyed by general relativity before 1960. (shrink)

This volume gathers together for the first time are all the key texts in a crucial debate in modern philosophy, centered on Leibniz's famous 1695 essay, the "New System of the Nature of Substances and their Communication," in which he introduced his strikingly original theory of metaphysics. His "system" became increasingly famous and drew him into discussion and development of these ideas, both in public and in private, with a variety of thinkers, most notably the great French philosopher Pierre Bayle. (...) Woolhouse's and Francks's new English edition gives the only full representation of this debate, and will therefore be essential reading for anyone who wishes to gain a proper understanding of Leibniz's philosophy and its intelletual context. All the texts are newly translated and extensively annotated; many appear in English for the first time. (shrink)

Plato's dialogues frequently criticize traditional Greek myth, yet Plato also integrates myth with his writing. Daniel S. Werner confronts this paradox through an in-depth analysis of the Phaedrus, Plato's most mythical dialogue. Werner argues that the myths of the Phaedrus serve several complex functions: they bring nonphilosophers into the philosophical life; they offer a starting point for philosophical inquiry; they unify the dialogue as a literary and dramatic whole; they draw attention to the limits of language and the limits of (...) knowledge; and they allow Plato to co-opt cultural authority as a way of defining and legitimating the practice of philosophy. Platonic myth, as a species of traditional tale, is thus both distinct from philosophical dialectic and similar to it. Ultimately, the most powerful effect of Platonic myth is the way in which it leads readers to participate in Plato's dialogues and to engage in a process of self-examination. (shrink)

t. 1. Apo ton prōto skeptomeno anthrōpo mechri ton 6. aiōna M.Ch. -- t. 2. Apo ton 7. aiōna M.Ch. mechri to sēmera.

We propose a formal framework for interpretable machine learning. Combining elements from statistical learning, causal interventionism, and decision theory, we design an idealised explanation game in which players collaborate to find the best explanation for a given algorithmic prediction. Through an iterative procedure of questions and answers, the players establish a three-dimensional Pareto frontier that describes the optimal trade-offs between explanatory accuracy, simplicity, and relevance. Multiple rounds are played at different levels of abstraction, allowing the players to explore overlapping causal (...) patterns of variable granularity and scope. We characterise the conditions under which such a game is almost surely guaranteed to converge on a optimal explanation surface in polynomial time, and highlight obstacles that will tend to prevent the players from advancing beyond certain explanatory thresholds. The game serves a descriptive and a normative function, establishing a conceptual space in which to analyse and compare existing proposals, as well as design new and improved solutions. (shrink)

Ariès traces Western man's attitudes toward mortality from the early medieval conception of death as the familiar collective destiny of the human race to the modern tendency, so pronounced in industrial societies, to hide death as if it were an embarrassing family secret.

Capital punishment—the legally authorized killing of a criminal offender by an agent of the state for the commission of a crime—stands in special need of moral justification. This is because execution is a particularly severe punishment. Execution is different in kind from monetary and custodial penalties in an obvious way: execution causes the death of an offender. While fines and incarceration set back some of one’s interests, death eliminates the possibility of setting and pursuing ends. While fines and incarceration narrow (...) one’s routes to happiness, death eliminates its possibility. Not surprisingly, there is much debate about the moral permissibility of capital punishment. This entry maps the terrain of this debate. The first section discusses justifications of the death penalty as they appear in major theories of punishment. The second section surveys moral objections to execution that apply to most justifications. The third addresses procedural criticisms, which do not target the morality of execution so much as the justice of its implementation. (shrink)

In Seeing Things as They Are (Searle 2015), Searle developed a direct realist’s theory of perception. According to direct realism, physical objects are directly and immediately perceived. Searle claims that Berkeley’s theory of perception goes against direct realism. For Searle, Berkeley’s theory suggests that only subjective experiences (ideas) are directly and immediately perceived, not physical objects. Contrary to Searle, G. S. Pappas claims that Berkeley’s theory of perception is consistent with the view that physical objects are immediately perceivable (Pappas 1982; (...) Pappas 1987). Given the conflicting interpretations of Berkeley’s theory of perception, this paper attempts to defend Searle’s position on Berkeley’s theory of perception. It refutes Pappas’ interpretation by arguing that he is inconsistent with Berkeley’s theses of ontological phenomenalism and heterogeneity thesis. (shrink)

In this original work of cultural criticism, Allen S. Weiss explores the meaning of radio to the modern imagination.