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The World (Descartes)
''The World'', also called ''Treatise on the Light'' ( French title: ''Traité du monde et de la lumière''), is a book by René Descartes (1596–1650). Written between 1629 and 1633, it contains a nearly complete version of his philosophy, from method, to metaphysics, to physics and biology. Descartes espoused mechanical philosophy, a form of natural philosophy popular in the 17th century. He thought everything physical in the universe to be made of tiny "corpuscles" of matter. Corpuscularianism is closely related to atomism. The main difference was that Descartes maintained that there could be no vacuum, and all matter was constantly swirling to prevent a void as corpuscles moved through other matter. ''The World'' presents a corpuscularian cosmology in which swirling vortices explain, among other phenomena, the creation of the Solar System and the circular motion of planets around the Sun. ''The World'' rests on the heliocentric view, first explicated in Western Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marin Mersenne
Marin Mersenne, OM (also known as Marinus Mersennus or ''le Père'' Mersenne; ; 8 September 1588 – 1 September 1648) was a French polymath whose works touched a wide variety of fields. He is perhaps best known today among mathematicians for Mersenne prime numbers, those which can be written in the form for some integer . He also developed Mersenne's laws, which describe the harmonics of a vibrating string (such as may be found on guitars and pianos), and his seminal work on music theory, ''Harmonie universelle'', for which he is referred to as the "father of acoustics". Mersenne, an ordained Catholic priest, had many contacts in the scientific world and has been called "the center of the world of science and mathematics during the first half of the 1600s" and, because of his ability to make connections between people and ideas, "the post-box of Europe". He was also a member of the Minim religious order and wrote and lectured on theology and philosophy. Life Mersenne was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1633 In Science
The year 1633 in science and technology involved some significant events. Events * June 22 – Galileo Galilei, the Italian scientist, is convicted of heresy by the Inquisition for his book ''Dialogue Concerning the Two Chief World Systems''. He is sentenced to house arrest for the remainder of his life. Botany * Jesuit scholar Giovanni Baptista Ferrari publishes ''De Florum Cultura'' in Rome, a pioneering text in floriculture. Chemistry * The first, crude, isolation of lactose, by Italian physician Fabrizio Bartoletti (1576–1630), is published. Births * c. May 1 – Sébastien Le Prestre de Vauban, French military engineer (died 1707) * May 28 - Nicolas Venette, French physician, sexologist and writer (died 1698) * November 3 – Bernardino Ramazzini, Italian physician, a founder of occupational medicine (died 1714) Deaths * November 7 – Cornelius Drebbel, Dutch inventor who built the first navigable submarine (born 1572) * November 8 – Xu Guangqi, Chinese polymath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1629 In Science
The year 1629 in science and technology involved some significant events. Botany * In London, John Parkinson publishes '. Chemistry * English alchemist Arthur Dee, court physician to Michael I of Russia, compiles ''Fasciculus Chemicus, Chymical Collections. Expressing the Ingress, Progress, and Egress, of the Secret Hermetick Science out of the choicest and most famous authors''. Medicine * Plague breaks out in Mantua and spreads to Milan. * In Toulouse, Niall Ó Glacáin publishes ''Tractatus de Peste''. Technology * In Rome, Giovanni Branca publishes '. Births * April 14 – Christiaan Huygens, Dutch mathematician and physicist (died 1695) * Laurent Cassegrain, French priest and physicist (died 1693) * Jan Commelijn, Dutch botanist (died 1692) * Christophe Glaser, Swiss pharmacian (died 1672) * Johann Glaser, Swiss anatomist (died 1675) * Agnes Block, Dutch horticulturalist (died 1704) Deaths * July 13 – Caspar Bartholin the Elder, Danish polymath, physician and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephen Gaukroger
Stephen Gaukroger, (born 9 July 1950) is a British/Australian historian of philosophy and science. He is Emeritus Professor of History of Philosophy and History of Science at the University of Sydney. Life Stephen Gaukroger was born in Oldham, Lancashire, and educated at Cardinal Langley Grammar School. He studied Philosophy at Birkbeck College, University of London, where he was awarded first class honours with the official congratulations of the Board of Examiners. He was a graduate student at Darwin College, Cambridge, completing his PhD in 1977 in the Department of History and Philosophy of Science. In 1977 he was elected to a research fellowship at Clare Hall, Cambridge, and at the end of 1978 moved to a research fellowship at the University of Melbourne. In 1981 he took up a lectureship in philosophy at the University of Sydney. He married Helen Irving Helen Irving (born April 8, 1954) is Professor Emerita at Sydney Law School, University of Sydney, Australia. Irving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Sean Mahoney
Michael Sean Mahoney (June 30, 1939 – July 23, 2008) was a historian of science. Mahoney was born in New York City, and did his undergraduate studies at Harvard University, graduating in 1960. He earned a Ph.D. in history and history of science from Princeton University in 1967, and immediately took a position as an assistant professor there. He remained at Princeton for over 40 years, until his death in 2008. A conference on the history of science and technology was held in his honor at Princeton in May 2009. Fermat biography Mahoney's biography of Pierre de Fermat received much critical attention including a scathing review by André Weil in 1973.... A second edition of Mahoney's book came out in 1994. Selected publications *Mahoney, Michael Sean, The mathematical career of Pierre de Fermat. Princeton University Press, Princeton, N.J., 1973. xviii+419 pp. *Mahoney, Michael Sean, The mathematical career of Pierre de Fermat, 1601–1665. Second edition. Princeton Paperbacks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, the solar wind, and cosmic rays to protect organisms from genetic damage. The current comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aether Theories
In physics, aether theories (also known as ether theories) propose the existence of a medium, a space-filling substance or field as a transmission medium for the propagation of electromagnetic or gravitational forces. Since the development of special relativity, theories using a substantial aether fell out of use in modern physics, and are now replaced by more abstract models. This early modern aether has little in common with the aether of classical elements from which the name was borrowed. The assorted theories embody the various conceptions of this medium and substance. Historical models Luminiferous aether Isaac Newton suggests the existence of an aether in the Third Book of ''Opticks'' (1st ed. 1704; 2nd ed. 1718): "Doth not this aethereal medium in passing out of water, glass, crystal, and other compact and dense bodies in empty spaces, grow denser and denser by degrees, and by that means refract the rays of light not in a point, but by bending them gradually in cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbits
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vortex
In fluid dynamics, a vortex ( : vortices or vortexes) is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved. Vortices form in stirred fluids, and may be observed in smoke rings, whirlpools in the wake of a boat, and the winds surrounding a tropical cyclone, tornado or dust devil. Vortices are a major component of turbulent flow. The distribution of velocity, vorticity (the curl of the flow velocity), as well as the concept of circulation are used to characterise vortices. In most vortices, the fluid flow velocity is greatest next to its axis and decreases in inverse proportion to the distance from the axis. In the absence of external forces, viscous friction within the fluid tends to organise the flow into a collection of irrotational vortices, possibly superimposed to larger-scale flows, including larger-scale vortices. Once formed, vortices can move, stretch, twist, and interact in complex ways. A moving vortex carries s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastic Collision
In physics, an elastic collision is an encounter (collision) between two bodies in which the total kinetic energy of the two bodies remains the same. In an ideal, perfectly elastic collision, there is no net conversion of kinetic energy into other forms such as heat, noise, or potential energy. During the collision of small objects, kinetic energy is first converted to potential energy associated with a repulsive or attractive force between the particles (when the particles move against this force, i.e. the angle between the force and the relative velocity is obtuse), then this potential energy is converted back to kinetic energy (when the particles move with this force, i.e. the angle between the force and the relative velocity is acute). Collisions of atoms are elastic, for example Rutherford backscattering. A useful special case of elastic collision is when the two bodies have equal mass, in which case they will simply exchange their momenta. The ''molecules''—as dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horror Vacui (physics)
In physics, horror vacui, or plenism (), commonly stated as "nature abhors a vacuum", is a postulate attributed to Aristotle, who articulated a belief, later criticized by the atomism of Epicurus and Lucretius, that nature contains no vacuums because the denser surrounding material continuum would immediately fill the rarity of an incipient void. He also argued against the void in a more abstract sense (as "separable"), for example, that by definition a void (equivocally?) itself, is nothing, and following Plato, nothing cannot rightly be said to exist. Furthermore, insofar as it would be featureless, it could neither be encountered by the senses, nor could its supposition lend additional explanatory power. Hero of Alexandria challenged the theory in the first century AD, but his attempts to create an artificial vacuum failed. The theory was debated in the context of 17th-century fluid mechanics, by Thomas Hobbes and Robert Boyle, among others, and through the early 18th century by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
