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Astronomy and Cosmology

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Martin van den Hove. Martin (Maarten) van den Hove (Latinized as Martinus Hortensius (Ortensius)) (1605 – 7 August 1639) was a Dutch astronomer and mathematician. His adopted Latin name is a translation of the Dutch hof ("garden"), in Latin horta. Early life[edit] Born in Delft, he studied at Leiden University under Snellius and Isaac Beeckman from 1625 to 1627. He received further instruction from Snellius from 1628 to 1630 at Leiden and at Ghent. Van den Hove and Philippe van Lansberge[edit] In 1628, he began studying under Philippe van Lansberge, who was introduced to him by Beeckman.

Van den Hove became an enthusiastic supporter of Landsberge, who was by now quite aged, and helped Landsberge complete his project to "restore astronomy" (i.e. create new systematic observations to replace old, insufficient data). Career as lecturer[edit] At the encouragement of Gerard Vossius and Caspar Barlaeus, Van den Hove began lecturing on the mathematical sciences at the Amsterdam Atheneum (Athenaeum Illustre) in 1634. Johannes Hevelius. For the ships, see MS Jan Heweliusz and ORP Heweliusz Etymology[edit] Early life[edit] Hevelius' father was Abraham Hewelke (1576–1649), his mother Kordula Hecker (1576–1655).

They were German-speaking Lutherans,[12] wealthy brewing merchants of Bohemian origin. As a young boy, Hevelius was sent to Gądecz (Gondecz) where he studied the Polish language.[13] Hevelius brewed the famous Jopen beer, which also gave its name to the "Jopengasse"/"Jopejska"[14][15] (after 1945 Piwna Street (Beer Street)),[16] the street where St. Astronomy[edit] Throughout his life, Hevelius took a leading part in municipal administration, becoming town councillor in 1651; but from 1639 on, his chief interest was astronomy. The observatory was known by the name Sternenburg[7][18] (Latin: Stellaeburgum; Polish: Gwiezdny Zamek) or "Star Castle"[19] This private observatory was visited by Polish Queen Marie Louise Gonzaga on 29 January 1660. Johannes Hevelius and wife Elisabeth making observations Works[edit] Jeremiah Horrocks. Jeremiah Horrocks (1618 – 3 January 1641), sometimes given as Jeremiah Horrox (the Latinised version that he used on the Emmanuel College register and in his Latin manuscripts),[1] was an English astronomer.

He was the first person to demonstrate that the Moon moved around the Earth in an elliptical orbit; and he was the only person to predict the transit of Venus of 1639, an event which he and his friend William Crabtree were the only two people to observe and record. His early death and the chaos of the English civil war nearly resulted in the loss to science of his treatise on the transit, Venus in sole visa; but for this and his other work he is acknowledged as one of the founding fathers of British astronomy. Early life and education[edit] Astronomical observations[edit] Now committed to the study of astronomy, Horrocks began to collect astronomical books and equipment; by 1638 he owned the best telescope he could find. Lunar research[edit] Transit of Venus[edit] " ...Thy return. Giovanni Domenico Cassini. Life[edit] Time in Italy[edit] "The first of a family of astronomers who settled in France and were prominent in directing the activities of the French school of astronomy until the Revolution, Cassini was the son of Jacopo Cassini, a Tuscan, and Julia Crovesi.

Cassini accepted a position at the observatory at Panzano, near Bologna, to work with Marquis Cornelio Malvasia, a rich amateur astronomer, in 1648 initiating the first part of Cassini's career. "[4] During Cassini's time at the Panzano Observatory, Cassini was able to complete his education under the scientists Giovanni Battista Riccioli and Francesco Maria Grimaldi. In 1650 the senate of Bologna appointed Cassini as the principal chair of astronomy at the University of Bologna.[4] Cassini remained in Bologna working until Colbert recruited him to come to Paris to help set up the Paris Observatory. Cassini departed from Bologna on 25 February 1669.[4] Moving to France[edit] Astronomer[edit] Astrologer[edit] Engineering[edit] Isaac Newton. Sir Isaac Newton PRS MP (/ˈnjuːtən/;[8] 25 December 1642 – 20 March 1726/7[1]) was an English physicist and mathematician (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time and as a key figure in the scientific revolution.

His book Philosophiæ Naturalis Principia Mathematica ("Mathematical Principles of Natural Philosophy"), first published in 1687, laid the foundations for classical mechanics. Newton made seminal contributions to optics, and he shares credit with Gottfried Leibniz for the development of calculus. Newton built the first practical reflecting telescope and developed a theory of colour based on the observation that a prism decomposes white light into the many colours of the visible spectrum. He formulated an empirical law of cooling, studied the speed of sound, and introduced the notion of a Newtonian fluid. Life Early life Isaac Newton (Bolton, Sarah K. Middle years Mathematics Optics. Newtonspmathema00newtrich. The mathematical principles of natural philosophy - Sir Isaac Newton, John Machin.

The mathematical principles of natural philosophy - Sir Isaac Newton. Books by Isaac Newton. Science Photo Library. Ole Rømer. Ole Christensen Rømer (Danish pronunciation: [o(ː)lə ˈʁœːˀmɐ]; 25 September 1644, Århus – 19 September 1710, Copenhagen) was a Danish astronomer who in 1676 made the first quantitative measurements of the speed of light. In scientific literature alternative spellings such as "Roemer", "Römer", or "Romer" are common. General biography[edit] Rundetårn, or round tower, in Copenhagen, on top of which the university had its observatory from the mid 17th century until the mid 19th century, when it was moved to new premises. The current observatory there was built in the 20th century to serve amateurs. Rømer was born on 25 September 1644 in Århus to a merchant and skipper, Christen Pedersen, and Anna Olufsdatter Storm, daughter of an alderman. Rømer was employed by the French government: Louis XIV made him tutor for the Dauphin, and he also took part in the construction of the magnificent fountains at Versailles.

Ole Rømer at work Roemer died at the age of 65 in 1710. 365·24·60⁄π·22 ≈ 7,600. R. Rømer's determination of the speed of light. Ole Rømer (1644–1710), depicted here some time after his discovery of the speed of light (1676), at a time when he was already a statesman in his native Denmark. The engraving is probably posthumous. Rømer's determination of the speed of light was the demonstration in 1676 that light has a finite speed, and so doesn't travel instantaneously. The discovery is usually attributed to Danish astronomer Ole Rømer (1644–1710),[note 1] who was working at the Royal Observatory in Paris at the time. Rømer estimated that light would take about 22 minutes to travel a distance equal to the diameter of Earth's orbit around the Sun: this is equivalent to about 220,000 kilometres per second in modern units, about 26% lower than the true value.

Rømer's theory was controversial at the time he announced it, and he never convinced the director of the Royal Observatory, Giovanni Domenico Cassini, to fully accept it. Background[edit] Eclipses of Io[edit] Observations[edit] Initial announcement[edit] [edit] Meridian circle. The similar transit instrument, transit circle or transit telescope is likewise mounted on a horizontal axis, but the axis need not be fixed in the east-west direction. For instance, a surveyor's theodolite can function as a transit instrument if its telescope is capable of a full revolution about the horizontal axis. Meridian circles are often called by these names, although they are less specific. For many years, transit timings were the most accurate method of measuring the positions of heavenly bodies, and meridian instruments were relied upon to perform this painstaking work.

Before spectroscopy, photography, and the perfection of reflecting telescopes, the measuring of positions (and the deriving of orbits and astronomical constants) was the major work of observatories.[1][2][3] Importance[edit] Meridian circle at Saint Petersburg Kunstkamera, built by T.L. Ertel, Germany, 1828 Basic instrument[edit] Construction[edit] Top view of a circle-reading microscope; from Norton (1867). John Flamsteed. John Flamsteed FRS (19 August 1646 – 31 December 1719) was an English astronomer and the first Astronomer Royal. He catalogued over 3000 stars.[1] Life[edit] Flamsteed was born in Denby, Derbyshire, England, the only son of Stephen Flamsteed and his first wife, Mary Spadman.

He was educated at the free school of Derby, and was educated at Derby School, in St Peter's Churchyard, Derby, near where his father carried on a malting business. At that time, most masters of the school were Puritans. Flamsteed had a solid knowledge of Latin, essential for reading the literature of the day, and a love of history, leaving the school in May, 1662.[2]:3–4 In September 1670, Flamsteed visited Cambridge and entered his name as an undergraduate at Jesus College.[3] While it seems he never took up full residence, he was there for two months in 1674, and had the opportunity to hear Isaac Newton's Lucasian Lectures.[2]:26 After his death, his papers and scientific instruments were taken by his widow. Samuel Molyneux. Samuel Molyneux FRS (16 July 1689 – 13 April 1728), son of William Molyneux, was an 18th-century member of the British parliament from Kew and an amateur astronomer whose work with James Bradley attempting to measure stellar parallax led to the discovery of the aberration of light.

The aberration was the first definite evidence that the earth moved and that Copernicus and Kepler were correct.[1][2][3] In addition to his astronomical works, Molyneux wrote about the natural history and other features of Ireland.[3] Life[edit] Astronomical Work[edit] Molyneux is best known for his work with Bradley in attempting to measure the parallax of Gamma Draconis leading to the discovery of the aberration of light.

Molyneux was interested in detecting parallax that others such Robert Hooke had attempted but failed to detect. Unlike Hooke, Molyneux had large amounts of patience and had resources to expend. Parliament[edit] In 1728, Molyneux suffered a fit while in the House of Commons. Notes[edit] James Bradley. James Bradley FRS (March 1693 – 13 July 1762) was an English astronomer and served as Astronomer Royal from 1742, succeeding Edmund Halley. He is best known for two fundamental discoveries in astronomy, the aberration of light (1725–1728), and the nutation of the Earth's axis (1728–1748).

These discoveries were called "the most brilliant and useful of the century" by Jean Baptiste Joseph Delambre, historian of astronomy, mathematical astronomer and director of the Paris Observatory, in his history of astronomy in the 18th century (1821), because "It is to these two discoveries by Bradley that we owe the exactness of modern astronomy. .... This double service assures to their discoverer the most distinguished place (after Hipparchus and Kepler) above the greatest astronomers of all ages and all countries. "[1] Biography[edit] He took orders on becoming vicar of Bridstow in the following year, and a small sinecure living in Wales was also procured for him by his friend Samuel Molyneux.