James Short and John Harrison: Personal Genius and Public Knowledge
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Newton's Aether Model
Newton’s aether model Eric Baird ([email protected]) Isaac Newton is usually associated with the idea of absolute space and time, and with ballistic light-corpuscle arguments. However, Newton was also a proponent of wave/particle duality, and published a “new” variable-density aether model in which light and matter trajectories were either bent by gravitational fields, or deflected by an aether density gradient. Newton’s (flawed) aether model can be considered as an early attempt at a curved-space model of gravity. 1. Introduction In “Opticks”, Newton’s idealised absolute space Modern textbooks typically say that Newton is occupied by a “new” form of medium whose believed that space and time were absolute and density depends on gravitational properties, inviolable. However, a reading of Newton’s with variations in aether density producing the “Principia” [1] and “Opticks” [2] reveals a effects that would otherwise be described as the rather different picture, with Optiks in results of a gravitational field. The resulting particular documenting Newton’s attempt to metric associates a gravitational field with produce a model of gravity in which a signal flight-time differences (see: Shapiro gravitational field could be represented as a effect) that deflect light, leading to a normalised series of light-distance differentials, or as a lightbeam-geometry that is not Euclidean. Since variation in lightspeed or refractive index. This these effects are described in modern theory as can be compared to Einstein’s “refractive” the effects of curved space, it seems reasonable approach to gravitational light-bending in 1911 to interpret Newton’s “absolute space” as an ( [3] §4 ) and to his description of general absolute Euclidean embedding-space that acts relativity as a (nonparticulate!) gravitational as a container for non-Euclidean geometry, aether model in 1920 [4][5]. -
Weighing the World the Reverend John Michell of Thornhill
66 Human Sciences Springer News 7/2011 springer.com/NEWSonline R. McCormmach, Eugene, OR, USA (Ed.) Weighing the World The Reverend John Michell of Thornhill The book about John Michell (1724-93) has two parts. The first and longest part is biographical, an account of Michell’s home setting (Notting- hamshire in England), the clerical world in which he grew up (Church of England), the university (Cambridge) where he studied and taught, and the scientific activities he made the center of his life. The second part is a complete edition of his known letters. Half of his letters have not been previously published; the other half are brought together in one place for the first time. The letters touch on all aspects of his career, and because they are in his words, they help bring the subject to life. His publi- cations were not many, a slim book on magnets and magnetism, one paper on geology, two papers on astronomy, and a few brief papers on other topics, but they were enough to leave a mark on several sciences. He has been called a geologist, an astronomer, and a physicist, which he was, though we best remember him as a natural philosopher, as one who investigated physical nature broadly. His scientific contribution is not easy to summa- rize. Arguably he had the broadest competence of any British natural philosopher of the eighteenth century: equally skilled in experiment and obser- vation, mathematical theory, and instruments, his field of inquiry was the universe. From the structure of the heavens through the structure of the Earth to the forces of the elementary particles of matter, he carried out original and far-reaching researches on the workings of nature. -
Philosophical Transactions, »
INDEX TO THE PHILOSOPHICAL TRANSACTIONS, » S e r ie s A, FOR THE YEAR 1898 (VOL. 191). A. Absorption, Change of, produced by Fluorescence (B urke), 87. Aneroid Barometers, Experiments on.—Elastic After-effect; Secular Change; Influence of Temperature (Chree), 441. B. Bolometer, Surface, Construction of (Petavel), 501. Brilliancy, Intrinsic, Law of Variation of, with Temperature (Petavel), 501. Burke (John). On the Change of Absorption produced by Fluorescence, 87. C. Chree (C.). Experiments on Aneroid Barometers at Kew Observatory, and their Discussion, 441. Correlation and Variation, Influence of Random Selection on (Pearson and Filon), 229. Crystals, Thermal Expansion Coefficients, by an Interference Method (Tutton), 313. D. Differential Equations of the Second Order, &c., Memoir on the Integration of; Characteristic Invariant of (Forsyth), 1. 526 INDEX. E. Electric Filters, Testing Efficiency of; Dielectrifying Power of (Kelvin, Maclean, and Galt), 187. Electricity, Diffusion of, from Carbonic Acid Gas to Air; Communication of, from Electrified Steam to Air (Kelvin, Maclean, and Galt), 187. Electrification of Air by Water Jet, Electrified Needle Points, Electrified Flame, &c., at Different Air-pressures; at Different Electrifying Potentials; Loss of Electrification (Kelvin, Maclean, and Galt), 187. Electrolytic Cells, Construction and Calibration of (Veley and Manley), 365. Emissivity of Platinum in Air and other Gases (Petavel), 501. Equations, Laplace's and other, Some New Solutions of, in Mathematical Physics (Forsyth), 1. Evolution, Mathematical Contributions to Theory o f; Influence of Random Selection on the Differentiation of Local Races (Pearson and Filon), 229. F. Filon (L. N. G.) and Pearson (Karl). Mathematical Contributions to the Theory of Evolution.—IV. On the Probable Errors of Frequency Constants and on the Influence of Random Selection on Variation and Correlation, 229. -
Official Publication of the Optometric Historical Society
Official Publication of the Optometric Historical Society Hindsight: Journal of Optometry History publishes material on the history of optometry and related topics. As the official publication of the Optometric Historical Society, Hindsight: Journal of Optometry History supports the purposes and functions of the Optometric Historical Society. The purposes of the Optometric Historical Society, according to its by-laws, are: ● to encourage the collection and preservation of materials relating to the history of optometry, ● to assist in securing and documenting the recollections of those who participated in the development of optometry, ● to encourage and assist in the care of archives of optometric interest, ● to identify and mark sites, landmarks, monuments, and structures of significance in optometric development, and ● to shed honor and recognition on persons, groups, and agencies making notable contributions toward the goals of the society. Officers and Board of Trustees of the Optometric Historical Society (with years of expiration of their terms on the Board in parentheses): President: John F. Amos (2015), email address: [email protected] Vice-President: Alden Norm Haffner (2014) Secretary-Treasurer: Chuck Haine (2016) Trustees: Jerry Abrams (2013) Arol Augsburger (2013) Irving Bennett (2016) Jay M. Enoch (2014) Morton Greenspoon (2015) Alfred Rosenbloom (2015) The official publication of the Optometric Historical Society, published quarterly since its beginning, was previously titled: Newsletter of the Optometric Historical Society, 1970-1991 (volumes 1-22), and Hindsight: Newsletter of the Optometric Historical Society, 1992-2006 (volumes 23-37). Use of the current title, Hindsight: Journal of Optometry History, began in 2007 with volume 38, number 1. On the cover: An image of the Chambers-Inskeep Ophthalmometer when it was introduced in 1899, from the May 24, 1899 issue of Jewelers Review (volume 32, page 652). -
Michell, Laplace and the Origin of the Black Hole Concept
Journal of Astronomical History and Heritage , 12(2), 90-96 (2009). MICHELL, LAPLACE AND THE ORIGIN OF THE BLACK HOLE CONCEPT Colin Montgomery, Wayne Orchiston and Ian Whittingham Centre for Astronomy, James Cook University, Townsville, Queensland 4811, Australia E-Mail: [email protected]; [email protected]; [email protected] Abstract: Black holes are fundamental to our understanding of modern astrophysics, yet the origin of this concept can be traced back to the writings of England’s John Michell and France’s Pierre-Simon Laplace in 1784 and 1796 respectively. Both independently postulated the existence of “non-luminous bodies”, and while Michell used graphical methods to explain his concept, Laplace published a mathematical ‘proof’ in 1799. Key Words: Michell, Laplace, black holes, missing mass, dark matter 1 INTRODUCTION There is no known image of John Michell but we have a description of him which was recorded in Cole The concept of a black hole is now widely accepted in MSS XXXIII, 156, in the British Library : astronomy and is applied to a range of bodies, extend- ing from extremely small primordial black holes form- John Michell, BD is a little short Man, of a black ed during the Big Bang with masses less than the Complexion, and fat; but having no Acquaintance with him, can say little of him. I think he had the care of St. mass of the Earth, to stellar-remnant black holes with Botolph’s Church, while he continued Fellow of masses of 3-30 M resulting from supernova explos- Queens’ College [Cambridge], where he was esteemed ions, up to supermassive black holes with masses of a very ingenious Man, and an excellent Philosopher. -
Cavendish Weighs the Earth, 1797
CAVENDISH WEIGHS THE EARTH Newton's law of gravitation tells us that any two bodies attract each other{not just the Earth and an apple, or the Earth and the Moon, but also two apples! We don't feel the attraction between two apples if we hold one in each hand, as we do the attraction of two magnets, but according to Newton's law, the two apples should attract each other. If that is really true, it might perhaps be possible to directly observe the force of attraction between two objects in a laboratory. The \great moment" when that was done came on August 5, 1797, in a garden shed in suburban London. The experimenter was Lord Henry Cavendish. Cavendish had inherited a fortune, and was therefore free to follow his inclinations, which turned out to be scientific. In addition to the famous experiment described here, he was also the discoverer of “inflammable air", now known as hydrogen. In those days, science in England was often pursued by private citizens of means, who communicated through the Royal Society. Although Cavendish studied at Cambridge for three years, the universities were not yet centers of scientific research. Let us turn now to a calculation. How much should the force of gravity between two apples actually amount to? Since the attraction between two objects is proportional to the product of their masses, the attraction between the apples should be the weight of an apple times the ratio of the mass of an apple to the mass of the Earth. The weight of an apple is, according to Newton, the force of attraction between the apple and the Earth: GMm W = R2 where G is the \gravitational constant", M the mass of the Earth, m the mass of an apple, and R the radius of the Earth. -
Articles Articles
Articles Articles ALEXI BAKER “Precision,” “Perfection,” and the Reality of British Scientific Instruments on the Move During the 18th Century Résumé Abstract On représente souvent les instruments scientifiques Early modern British “scientific” instruments, including du 18e siècle, y compris les chronomètres de précision, precision timekeepers, are often represented as static, comme des objets statiques, à l’état neuf et complets en pristine, and self-contained in 18th-century depictions eux-mêmes dans les descriptions des débuts de l’époque and in many modern museum displays. In reality, they moderne et dans de nombreuses expositions muséales were almost constantly in physical flux. Movement and d’aujourd’hui. En réalité, ces instruments se trouvaient changing and challenging environmental conditions presque constamment soumis à des courants physiques. frequently impaired their usage and maintenance, Le mouvement et les conditions environnementales especially at sea and on expeditions of “science” and difficiles et changeantes perturbaient souvent leur exploration. As a result, individuals’ experiences with utilisation et leur entretien, en particulier en mer et mending and adapting instruments greatly defined the lors d’expéditions scientifiques et d’exploration. Ce culture of technology and its use as well as later efforts sont donc les expériences individuelles de réparation at standardization. et d’adaptation des instruments qui ont grandement contribué à définir la culture de la technologie. In 1769, the astronomer John Bradley finally the calculation of the distance between the Earth reached the Lizard peninsula in Cornwall and the Sun. Bradley had not needed to travel with his men, instruments, and portable tent as far as many of his Transit counterparts, but observatory after a stressful journey. -
Of Dr. John Huxham
Medical History, 1981, 25: 415421. THE FAME AND NOTORIETY OF DR. JOHN HUXHAM by WILLIAM SCHUPBACH* JOHN HUXHAM, M.D., F.R.S., F.R.C.P. Edinburgh (c. 1692-1768), was an English physician whose practice was confined to Plymouth but whose writings were read throughout Europe. His literary career started with his Observationes de aere et morbis epidemicis (1739), in which meteorological records made at Plymouth from 1728 to 1737 were collated month by month with the diseases observed there. Further volumes followed the same plan from 1738 to 1748, and from 1748 to 1752. In these works there is a now conspicuous contrast between the meteorological records, which are elaborately quantified according to a scheme laid down by James Jurin, F.R.S., in 1723, and the notes on morbidity and mortality, which are superficial and sometimes reduced to names of prevalent diseases. To do justice to the extensive medical knowledge which he acquired in compiling these observations, Huxham therefore published separate treatises on the Devonshire colic, on diphtheria, on smallpox, and his best-known work, An essay on fevers (1750), which was translated into Latin, French, and Italian. Here Huxham discussed the conditions under which fevers appeared, the different types of fevers, and the remedies which, according to his reasoning, should tend to cure them. Hippocrates, "the best and oldest master of our profession"',' is. the presiding genius of the work, but Sydenham and Huxham's teacher Boerhaave are also drawn on, and Huxham's own cases are introduced at intervals.2 Huxham's writings must have been received with great interest, for they were published in London, Edinburgh, Amsterdam, Bremen, Munich, Paris, Venice, Naples, and Lisbon. -
212 Publications of the Some Pioneer
212 PUBLICATIONS OF THE SOME PIONEER OBSERVERS1 By Frank Schlesinger In choosing a subject upon which to speak to you this eve- ning, I have had to bear in mind that, although this is a meeting of the Astronomical Society of the Pacific, not many of my audience are astronomers, and I am therefore debarred from speaking on too technical a matter. Under these circumstances I have thought that a historical subject, and one that has been somewhat neglected by the, formal historians of our science, may be of interest. I propose to outline, very briefly of course, the history of the advances that have been made in the accuracy of astronomical measurements. To do this within an hour, I must confine myself to the measurement of the relative places of objects not very close together, neglecting not only measure- ments other than of angles, but also such as can be carried out, for example, by the filar micrometer and the interferometer; these form a somewhat distinct chapter and would be well worth your consideration in an evening by themselves. It is clear to you, I hope, in how restricted a sense I am using the word observer ; Galileo, Herschel, and Barnard were great observers in another sense and they were great pioneers. But of their kind of observing I am not to speak to you tonight. My pioneers are five in number ; they are Hipparchus in the second century b.c., Tycho in the sixteenth century, Bradley in the eighteenth, Bessel in the first half of the nineteenth century and Rüther fur d in the second half. -
Section II: Summary of the Periodic Report on the State of Conservation, 2006
State of Conservation of World Heritage Properties in Europe SECTION II workmanship, and setting is well documented. UNITED KINGDOM There are firm legislative and policy controls in place to ensure that its fabric and character and Maritime Greenwich setting will be preserved in the future. b) The Queen’s House by Inigo Jones and plans for Brief description the Royal Naval College and key buildings by Sir Christopher Wren as masterpieces of creative The ensemble of buildings at Greenwich, an genius (Criterion i) outlying district of London, and the park in which they are set, symbolize English artistic and Inigo Jones and Sir Christopher Wren are scientific endeavour in the 17th and 18th centuries. acknowledged to be among the greatest The Queen's House (by Inigo Jones) was the first architectural talents of the Renaissance and Palladian building in England, while the complex Baroque periods in Europe. Their buildings at that was until recently the Royal Naval College was Greenwich represent high points in their individual designed by Christopher Wren. The park, laid out architectural oeuvres and, taken as an ensemble, on the basis of an original design by André Le the Queen’s House and Royal Naval College Nôtre, contains the Old Royal Observatory, the complex is widely recognised as Britain’s work of Wren and the scientist Robert Hooke. outstanding Baroque set piece. Inigo Jones was one of the first and the most skilled 1. Introduction proponents of the new classical architectural style in England. On his return to England after having Year(s) of Inscription 1997 travelled extensively in Italy in 1613-14 he was appointed by Anne, consort of James I, to provide a Agency responsible for site management new building at Greenwich. -
Philosophical Transactions (A)
INDEX TO THE PHILOSOPHICAL TRANSACTIONS (A) FOR THE YEAR 1889. A. A bney (W. de W.). Total Eclipse of the San observed at Caroline Island, on 6th May, 1883, 119. A bney (W. de W.) and T horpe (T. E.). On the Determination of the Photometric Intensity of the Coronal Light during the Solar Eclipse of August 28-29, 1886, 363. Alcohol, a study of the thermal properties of propyl, 137 (see R amsay and Y oung). Archer (R. H.). Observations made by Newcomb’s Method on the Visibility of Extension of the Coronal Streamers at Hog Island, Grenada, Eclipse of August 28-29, 1886, 382. Atomic weight of gold, revision of the, 395 (see Mallet). B. B oys (C. V.). The Radio-Micrometer, 159. B ryan (G. H.). The Waves on a Rotating Liquid Spheroid of Finite Ellipticity, 187. C. Conroy (Sir J.). Some Observations on the Amount of Light Reflected and Transmitted by Certain 'Kinds of Glass, 245. Corona, on the photographs of the, obtained at Prickly Point and Carriacou Island, total solar eclipse, August 29, 1886, 347 (see W esley). Coronal light, on the determination of the, during the solar eclipse of August 28-29, 1886, 363 (see Abney and Thorpe). Coronal streamers, observations made by Newcomb’s Method on the Visibility of, Eclipse of August 28-29, 1886, 382 (see A rcher). Cosmogony, on the mechanical conditions of a swarm of meteorites, and on theories of, 1 (see Darwin). Currents induced in a spherical conductor by variation of an external magnetic potential, 513 (see Lamb). 520 INDEX. -
Back Matter (PDF)
[ 395 ] INDEX TO THE PHILOSOPHICAL TRANSACTIONS, S e r ie s A, V o l . 193. A. Abney (W. de W.). The Colour Sensations in Terms of Luminosity, 259. Atmospheric electricity—experiments in connection with precipitation (Wilson), 289. Bakebian Lectube. See Ewing and Kosenhain. C. Colour-blind, neutral points in spectra found by (Abney), 259. Colour sensations in terms of luminosity (Abney), 259. Condensation nuclei, positively and negatively charged ions as (W ilson), 289. Crystalline aggregates, plasticity in (Ewing and Rosenhain), 353. D. Dawson (H. M.). See Smithells, Dawson, and Wilson VOL. CXCIII.— Ao : S F 396 INDEX. Electric spark, constitution of (Schuster and Hemsalech), 189; potential—variation with pressure (Strutt), 377. Electrical conductivity of flames containing vaporised salts (Smithells, Dawson, and Wilson), 89. Electrocapillary phenomena, relation to potential differences between‘solutions (Smith), 47. Electrometer, capillary, theory of (Smith), 47. Ewing (J. A.) and Rosenhain (W.). The Crystalline Structure of Metals.—Bakerian Lecture, 353. F. Filon (L. N. G ). On the Resistance to Torsion of certain Forms of Shafting, with special Reference to the Effect of Keyways, 309. Flames, electrical conductivity of, and luminosity of salt vapours in (Smithells, Dawson, and Wilson), 89. G. Gravity balance, quartz thread (Threlfall and Pollock), 215. H. Hemsalech (Gustav). See Schuster and Hemsalech. Hertzian oscillator, vibrations in field of (Pearson and Lee), 159. Hysteresis in the relation of extension to stress exhibited by overstrained iron (Muir), 1. I. Ions, diffusion into gases, determination of coefficient (Townsend), 129. Ions positively and negatively charged, as condensation nuclei (Wilson), 289. Iron, recovery of, from overstrain (Muir), 1.