Strasbourg astronomical clock

The Strasbourg astronomical clock is located in the Cathédrale Notre-Dame of Strasbourg, Alsace, France. It is the third clock on that spot and dates from the time of the first French possession of the city (1681–1870). The first clock had been built in the 14th century, the second in the 16th century, when Strasbourg was a Free imperial city of the Holy Roman Empire.
The current, third clock dates from 1843. Its main features, besides the automata, are a perpetual calendar (including a "computus"), an orrery (planetary dial), a display of the real position of the Sun and the Moon, and solar and lunar eclipses. The main attraction is the procession of the 18 inch high figures of Christ and the Apostles, which occurs every day at solar noon, while the life-size cock crows thrice.
Clocks.
First clock.
The Third of its kind against the south transept. The name of its maker is not known. This clock was known as the "Three Kings clock" and had several automata. One of them was the gilded rooster, later reused in the second clock and which now is part of the collections of the Strasbourg Museum for Decorative Arts and is considered the oldest preserved automaton worldwide. This bird, a symbol of Christ's passion, was made of iron, copper, and wood. At noon it flapped its wings and spread out its feathers. It also opened its beak, put out its tongue, and by means of a bellows and a reed, crowed. In the top compartment at noon, to the sound of a small carillon, the Three Kings bowed before the figure of The Virgin Mary and the Christ Child.
The clock most certainly had an astrolabe dial and a calendar dial. It was standing on the wall opposite the current clock, and a staircase led to its various levels. Supports for former balconies can still be seen today, and suggest that the height of the clock was about 18 m (59'), with a width of about 7.70 m (25') at the base. At the base a painted figure of a zodiacal man showed the relationship between the signs of the zodiac and parts of the human body.
There is also a big circle engraved in the wall, but this circle is not a remnant of the first clock. It was added at a later stage, for some unclarified reason.
The entire structure was dismantled in 1572–4 when the second and even more ambitious clock was mounted on the opposite wall of the south transept.
Second clock.
The first clock stopped working and a new one was started in the 16th century. It was designed by the mathematician Christian Herlin. During a first phase, the stone case and the staircase were built, around 1547, and the dial and iron framework were being constructed when work halted, due to the various political problems - the cathedral became Catholic - and also due to the deaths of Herlin and his associates.
Construction was resumed in 1571 by Conrad Dasypodius, a pupil of and successor to Herlin. Dasypodius enrolled the Swiss clockmakers Isaac Habrecht and Josia Habrecht, as well as the astronomer and musician David Wolckenstein, and Swiss artists Tobias Stimmer and his brother Josias. The clock was completed in 1574.
This clock was remarkable both for its complexity as an astronomical device and for the range and richness of its decorations and accessories. As well as the many dials and indicators - the calendar dial, the astrolabe, the indicators for planets, and eclipses - the clock was also well endowed with paintings, moving statues, automata, and musical entertainment in the form of a six tune carillon. The Stimmers painted large panels that depicted the three Fates, Urania, Colossus, Nicolaus Copernicus, and various sacred themes, including the Creation, the resurrection of the Dead, the last judgment, and the rewards of virtue and vice.
At the base of a clock there was an 86 cm (34") diameter celestial globe, accompanied by the figure of a pelican. The globe was connected to the clock movement, and set for the meridian of Strasbourg.
A popular feature of the new clock was the golden cockerel, a relic of the first clock, which perched on the top of the cupola and entertained the onlookers at noon every day until 1640, when it was struck by lightning.
Most of the works are still preserved in the Museum of Decorative Arts.
Third clock.
The second clock stopped working around 1788 and stood still until 1838, when Jean-Baptiste Schwilgué (1776–1856) started to build the current clock. He designed new mechanisms to replace the old ones and which were meant to be state of the art. Schwilgué had wanted to work on the clock since his boyhood, but he only got the contract 50 years later. In the meantime, he had become acquainted with clockmaking, mathematics, and mechanics. He spent one year preparing his 30 workers before actually starting construction. Then, construction lasted from 1838 until June 24, 1843. The clock, however, was inaugurated on December 31, 1842.
The gold hands of the clock show mean solar time, or "temps moyen"; the silver hands show Central European Time, labelled "heure publique". In winter, mean solar time is approximately 30½ minutes behind Central European Time.
This clock contains probably the first perpetual mechanical Gregorian computus, designed by Schwilgué in 1816. In the 1970s, Frédéric Klinghammer built a reduced replica of it.
Model.
In 1887, a 25-year-old Sydney watchmaker named Richard Smith built a working model of the third clock in the scale 1:5.
Having never seen the original, Smith had to work from a pamphlet which described its timekeeping and astronomical functions.
This model is in the collection of the Powerhouse Museum, Sydney, Australia.


Deferent and epicycle

In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (from , literally "upon the circle", meaning "circle moving on another circle") was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets. In particular it explained the apparent retrograde motion of the five planets known at the time. Secondarily, it also explained changes in the apparent distances of the planets from the Earth.
It was first proposed by Apollonius of Perga at the end of the 3rd century BC. It was developed by Apollonius of Perga and Hipparchus of Rhodes, who used it extensively, during the 2nd century BC, then formalized and extensively used by Ptolemy of Thebaid in his 2nd century AD astronomical treatise the "Almagest".
Epicyclical motion is used in the Antikythera mechanism, an ancient Greek astronomical device for compensating for the elliptical orbit of the Moon, moving faster at perigee and slower at apogee than circular orbits would, using four gears, two of them engaged in an eccentric way that quite closely approximates Kepler's second law.
Epicycles worked very well and were highly accurate, because, as Fourier analysis later showed, any smooth curve can be approximated to arbitrary accuracy with a sufficient number of epicycles. However, they fell out of favour with the discovery that planetary motions were largely elliptical from a heliocentric frame of reference, which led to the discovery that gravity obeying a simple inverse square law could better explain all planetary motions.
Introduction.
In both Hipparchian and Ptolemaic systems, the planets are assumed to move in a small circle called an "epicycle", which in turn moves along a larger circle called a "deferent". Both circles rotate clockwise and are roughly parallel to the plane of the Sun's orbit (ecliptic). Despite the fact that the system is considered geocentric, each planet's motion was not centered on the Earth but at a point slightly away from the Earth called the "eccentric". The orbits of planets in this system are similar to epitrochoids.
In the Hipparchian system the epicycle rotated and revolved along the deferent with uniform motion. However, Ptolemy found that he could not reconcile that with the Babylonian observational data available to him; in particular, the shape and size of the apparent retrogrades differed. The angular rate at which the epicycle traveled was not constant unless he measured it from another point which he called the "equant". It was the angular rate at which the deferent moved around the point midway between the equant and the Earth (the eccentric) that was constant; the epicycle center swept out equal angles over equal times only when viewed from the equant. It was the use of equants to decouple uniform motion from the center of the circular deferents that distinguished the Ptolemaic system.
Ptolemy did not predict the relative sizes of the planetary deferents in the "Almagest". All of his calculations were done with respect to a normalized deferent, considering a single case at a time. This is not to say that he believed the planets were all equidistant, but he had no basis on which to measure distances, except for the Moon. He generally ordered the planets outward from the Earth based on their orbit periods. Later he calculated their distances in the "Planetary Hypotheses" and summarized them in the first column of this table:
Had his values for deferent radii relative to the Earth–Sun distance been more accurate, the epicycle sizes would have all approached the Earth–Sun distance. Although all the planets are considered separately, in one peculiar way they were all linked: the lines drawn from the body through the epicentric center of all the planets were all parallel, along with the line drawn from the Sun to the Earth along which Mercury and Venus were situated. That means that all the bodies revolve in their epicycles in lockstep with Ptolemy's Sun (that is, they all have exactly a one-year period).
Babylonian observations showed that for superior planets the planet would typically move through in the night sky slower than the stars. Each night the planet appeared to lag a little behind the stars, in what is called prograde motion. Near opposition, the planet would appear to reverse and move through the night sky faster than the stars for a time in retrograde motion before reversing again and resuming prograde. Epicyclic theory, in part, sought to explain this behavior.
The inferior planets were always observed to be near the Sun, appearing only shortly before sunrise or shortly after sunset. Their apparent retrograde motion occurs during the transition between evening star into morning star, as they pass between the Earth and the Sun.
History.
When ancient astronomers viewed the sky, they saw the Sun, Moon, and stars moving overhead in a regular fashion. They also saw the "wanderers" or "planetai" (our planets). The regularity in the motions of the wandering bodies suggested that their positions might be predictable.
The most obvious approach to the problem of predicting the motions of the heavenly bodies was simply to map their positions against the star field and then to fit mathematical functions to the changing positions.
The ancients worked from a geocentric perspective for the simple reason that the Earth was where they stood and observed the sky, and it is the sky which appears to move while the ground seems still and steady underfoot. Some Greek astronomers (e.g., Aristarchus of Samos) speculated that the planets (Earth included) orbited the Sun, but the optics (and the specific mathematics – Isaac Newton's Law of Gravitation for example) necessary to provide data that would convincingly support the heliocentric model did not exist in Ptolemy's time and would not come around for over fifteen hundred years after his time. Furthermore, Aristotelian physics was not designed with these sorts of calculations in mind, and Aristotle's philosophy regarding the heavens was entirely at odds with the concept of heliocentrism. It was not until Galileo Galilei observed the moons of Jupiter on 7 January 1610, and the phases of Venus in September 1610 that the heliocentric model began to receive broad support among astronomers, who also came to accept the notion that the planets are individual worlds orbiting the Sun (that is, that the Earth is a planet and is one among several). Johannes Kepler was able to formulate his three laws of planetary motion, which described the orbits of the planets in our solar system to a remarkable degree of accuracy; Kepler's three laws are still taught today in university physics and astronomy classes, and the wording of these laws has not changed since Kepler first formulated them four hundred years ago.
The apparent motion of the heavenly bodies with respect to time is cyclical in nature. Apollonius of Perga realized that this cyclical variation could be represented visually by small circular orbits, or "epicycles", revolving on larger circular orbits, or "deferents". Hipparchus calculated the required orbits. Deferents and epicycles in the ancient models did not represent orbits in the modern sense.
Claudius Ptolemy refined the deferent-and-epicycle concept and introduced the equant as a mechanism for accounting for velocity variations in the motions of the planets. The empirical methodology he developed proved to be extraordinarily accurate for its day and was still in use at the time of Copernicus and Kepler.
Owen Gingerich describes a planetary conjunction that occurred in 1504 that was apparently observed by Copernicus. In notes bound with his copy of the "Alfonsine Tables", Copernicus commented that "Mars surpasses the numbers by more than two degrees. Saturn is surpassed by the numbers by one and a half degrees." Using modern computer programs, Gingerich discovered that, at the time of the conjunction, Saturn indeed lagged behind the tables by a degree and a half and Mars led the predictions by nearly two degrees. Moreover, he found that Ptolemy's predictions for Jupiter at the same time were quite accurate. Copernicus and his contemporaries were therefore using Ptolemy's methods and finding them trustworthy well over a thousand years after Ptolemy's original work was published.
When Copernicus transformed Earth-based observations to heliocentric coordinates, he was confronted with an entirely new problem. The Sun-centered positions displayed a cyclical motion with respect to time but without retrograde loops in the case of the outer planets. In principle, the heliocentric motion was simpler but with new subtleties due to the yet-to-be-discovered elliptical shape of the orbits. Another complication was caused by a problem that Copernicus never solved: correctly accounting for the motion of the Earth in the coordinate transformation. In keeping with past practice, Copernicus used the deferent/epicycle model in his theory but his epicycles were small and were called "epicyclets".
In the Ptolemaic system the models for each of the planets were different and so it was with Copernicus' initial models. As he worked through the mathematics, however, Copernicus discovered that his models could be combined in a unified system. Furthermore, if they were scaled so that the Earth's orbit was the same in all of them, the ordering of the planets we recognize today easily followed from the math. Mercury orbited closest to the Sun and the rest of the planets fell into place in order outward, arranged in distance by their periods of revolution.
Although Copernicus' models reduced the magnitude of the epicycles considerably, whether they were simpler than Ptolemy's is moot. Copernicus eliminated Ptolemy's somewhat-maligned equant but at a cost of additional epicycles. Various 16th-century books based on Ptolemy and Copernicus use about equal numbers of epicycles. The idea that Copernicus used only 34 circles in his system comes from his own statement in a preliminary unpublished sketch called the "Commentariolus". By the time he published "De revolutionibus orbium coelestium", he had added more circles. Counting the total number is difficult, but estimates are that he created a system just as complicated, or even more so. Koestler, in his history of man's vision of the universe, equates the number of epicycles used by Copernicus at 48. The popular total of about 80 circles for the Ptolemaic system seems to have appeared in 1898. It may have been inspired by the "non-Ptolemaic" system of Girolamo Fracastoro, who used either 77 or 79 orbs in his system inspired by Eudoxus of Cnidus. Copernicus in his works exaggerated the number of epicycles used in the Ptolemaic system; although original counts ranged to 80 circles, by Copernicus's time the Ptolemaic system had been updated by Peurbach towards the similar number of 40; hence Copernicus effectively replaced the problem of retrograde with further epicycles.
Copernicus' theory was at least as accurate as Ptolemy's but never achieved the stature and recognition of Ptolemy's theory. What was needed was Kepler's elliptical theory, not published until 1609 and 1619. Copernicus' work provided explanations for phenomena like retrograde motion, but really did not prove that the planets actually orbited the Sun.
Ptolemy's and Copernicus' theories proved the durability and adaptability of the deferent/epicycle device for representing planetary motion. The deferent/epicycle models worked as well as they did because of the extraordinary orbital stability of the solar system. Either theory could be used today had Gottfried Wilhelm Leibniz and Isaac Newton not invented calculus.
The first planetary model without any epicycles was that of Ibn Bajjah (Avempace) in 12th century Andalusian Spain, but epicycles were not eliminated in Europe until the 17th century, when Johannes Kepler's model of elliptical orbits gradually replaced Copernicus' model based on perfect circles.
Newtonian or classical mechanics eliminated the need for deferent/epicycle methods altogether and produced more accurate theories. By treating the Sun and planets as point masses and using Newton's law of universal gravitation, equations of motion were derived that could be solved by various means to compute predictions of planetary orbital velocities and positions. Simple two-body problems, for example, can be solved analytically. More-complex n-body problems require numerical methods for solution.
The power of Newtonian mechanics to solve problems in orbital mechanics is illustrated by the discovery of Neptune. Analysis of observed perturbations in the orbit of Uranus produced estimates of the suspected planet's position within a degree of where it was found. This could not have been accomplished with deferent/epicycle methods. Still, Newton in 1702 published "Theory of the Moon's Motion" which employed an epicycle and remained in use in China into the nineteenth century. Subsequent tables based on Newton's "Theory" could have approached arcminute accuracy.
Epicycles.
According to one school of thought in the history of astronomy, minor imperfections in the original Ptolemaic system were discovered through observations accumulated over time. It was mistakenly believed that more levels of epicycles (circles within circles) were added to the models to match more accurately the observed planetary motions. The multiplication of epicycles is believed to have led to a nearly unworkable system by the 16th century, and that Copernicus created his heliocentric system in order to simplify the Ptolemaic astronomy of his day, thus succeeding in drastically reducing the number of circles.
As a measure of complexity, the number of circles is given as 80 for Ptolemy, versus a mere 34 for Copernicus. The highest number appeared in the "Encyclopædia Britannica" on Astronomy during the 1960s, in a discussion of King Alfonso X of Castile's interest in astronomy during the 13th century. (Alfonso is credited with commissioning the Alfonsine Tables.)
As it turns out, a major difficulty with this epicycles-on-epicycles theory is that historians examining books on Ptolemaic astronomy from the Middle Ages and the Renaissance have found absolutely no trace of multiple epicycles being used for each planet. The Alfonsine Tables, for instance, were apparently computed using Ptolemy's original unadorned methods.
Another problem is that the models themselves discouraged tinkering. In a deferent-and-epicycle model, the parts of the whole are interrelated. A change in a parameter to improve the fit in one place would throw off the fit somewhere else. Ptolemy's model is probably optimal in this regard. On the whole it gave good results but missed a little here and there. Experienced astronomers would have recognized these shortcomings and allowed for them.
Mathematical formalism.
According to the historian of science Norwood Russell Hanson:
Any path—periodic or not, closed or open—can be represented with an infinite number of epicycles.
This is because epicycles can be represented as a complex Fourier series; so, with a large number of epicycles, very complicated paths can be represented in the complex plane.
Let the complex number
where and are constants, is the imaginary unit, and is time, correspond to a deferent centered on the origin of the complex plane and revolving with a radius and angular velocity
where is the period.
If is the path of an epicycle, then the deferent plus epicycle is represented as the sum
This is an almost periodic function, and is a periodic function just when the ratio of the constants is rational. Generalizing to epicycles yields the almost periodic function
which is periodic just when every pair of is rationally related. Finding the coefficients to represent a time-dependent path in the complex plane, , is the goal of reproducing an orbit with deferent and epicycles, and this is a way of "saving the phenomena" (σώζειν τα φαινόμενα).
This parallel was noted by Giovanni Schiaparelli. Pertinent to the Copernican Revolution's debate about "saving the phenomena" versus offering explanations, one can understand why Thomas Aquinas, in the 13th century, wrote:
Bad science.
In part, due to misunderstandings about how deferent/epicycle models worked, "adding epicycles" has come to be used as a derogatory comment in modern scientific discussion. The term might be used, for example, to describe continuing to try to adjust a theory to make its predictions match the facts. There is a generally accepted idea that extra epicycles were invented to alleviate the growing errors that the Ptolemaic system noted as measurements became more accurate, particularly for Mars. According to this notion, epicycles are regarded by some as the paradigmatic example of bad science. Part of the problem may be due to the misconception of the epicycle as an explanation of a body's motion rather than merely a description. Toomer explains as follows,
Copernicus added an extra epicycle to his planets, but that was only in an effort to eliminate Ptolemy's equant, which he considered a philosophical break away from Aristotle's perfection of the heavens. Mathematically, the second epicycle and the equant produce the same results, and many Copernican astronomers before Kepler continued using the equant, as the math was easier.


Stellar atmosphere

The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone.
Overview.
The stellar atmosphere is divided into several regions of distinct character:
During a total solar eclipse, the photosphere of the Sun is obscured, revealing its atmosphere's other layers. Observed during eclipse, the Sun's chromosphere appears (briefly) as a thin pinkish arc, and its corona is seen as a tufted halo. The same phenomenon in eclipsing binaries can make the chromosphere of giant stars visible.


53P/Van Biesbroeck

53P/Van Biesbroeck is a periodic comet 7 km in diameter.
This comet and 42P/Neujmin are fragments of a parent comet that split around March 1845. The orbit of 53P/Van Biesbroeck has a Jupiter Minimum orbit intersection distance (MOID) of only . The next perihelion passage is on Christmas Eve 24 December 2028. The comet is expected to brighten to about apparent magnitude 14.


James Gunn (astronomer)

James Edward Gunn (born October 21, 1938) is the Eugene Higgins Professor of Astronomy at Princeton University. Gunn's early theoretical work in astronomy has helped establish the current understanding of how galaxies form, and the properties of the space between galaxies. He also suggested important observational tests to confirm the presence of dark matter in galaxies, and predicted the existence of a Gunn–Peterson trough in the spectra of distant quasars.
Much of Gunn's later work has involved leadership in major observational projects. He developed plans for one of the first uses of digital camera technology for space observation, a project that led to the Sloan Digital Sky Survey, the most extensive three-dimensional mapping of the universe ever undertaken. He also played a major role with the Wide Field and Planetary Camera on the Hubble Space Telescope.
Gunn graduated from A.C. Jones High School in Beeville, Texas in 1957. He earned his bachelor's degree at Rice University in Houston, Texas, in 1961, and his Ph.D. from the California Institute of Technology (Caltech) in 1965. He joined the faculty of Princeton University two years later. Subsequently, he worked at the University of California at Berkeley and Caltech before returning to Princeton. He is married to the astronomer Gillian Knapp and they have two children, Humberto and Marleny Gunn.


Columba in Chinese astronomy

The modern constellation Columba lies across two of the quadrants, symbolized by the White Tiger of the West (西方白虎, "Xī Fāng Bái Hǔ") and the Vermillion Bird of the South (南方朱雀, "Nán Fāng Zhū Què"), that divide the sky in traditional Chinese uranography.
The name of the western constellation in modern Chinese is 天鴿座 ("tiān gē zuò"), meaning "the heaven dove constellation".
Stars.
The map of Chinese constellation in constellation Columba area consists of :


Ashapatti Tamrakar

Ashapatti Tamrakar (Devanagari: आशापति ताम्रकार) (1904–1942) was a pioneer optician of Nepal. He imported and dispensed spectacles, and was trained in ophthalmology and orthoposcopy when such specialists were practically unheard of in Nepal.
Early life.
Tamrakar was born in Maru, Kathmandu Durbar Square to father Pranpati and mother Hera Laxmi. His father was a herbalist, and he trained under him and joined the family business of dispensing herbal medicines. The Tamrakars had given up their ancestral occupation generations ago. Many of Tamrakar's relatives were artisans and practiced their hereditary occupation of making household utensils of copper and lamps and other ritual objects of silver, according to the division of labor laid down in ancient times.
Tamrakar's first wife died leaving him a son Rampati. In 1927, he got married a second time to Moti Lani Tuladhar who bore him a daughter Hira Shobha.
Medical practice.
Tamrakar's firm Ashapatti & Son, which was based in his home, imported spectacles from India. Subsequently, he imported an edging machine and also made reading glasses. In 1935, he travelled to Kolkata and enrolled at United Optical Service at 54 Bowbazar Street to receive training in ophthalmology and orthoposcopy.
Besides being an optician, Tamrakar was engaged as a herbalist and compounder. In 1939, he went to Kolkata and served briefly as a dresser in the wards and operation theater of Campbell Medical School and Hospital, which has since been renamed Nil Ratan Sircar Medical College and Hospital. He also worked as an anesthetist at Bir Hospital in Kathmandu.
Forward-minded.
Tamrakar was a firm believer in female education, an idea which was frowned upon during his time. He insisted on his daughter going to school and enrolled her at Kanya Pathshala at Durbar Square, one of the very few in existence in the country. This was a school for girls run by Chandra Kanta Joshi, sister of martyr Shukra Raj Shastri.
Tamrakar contracted tuberculosis in his later years for which treatment was not available in Nepal in those days. He died at his home in 1942 at the age of 38.


Austin Planetarium


George Nixon (cricketer)

George Tait St Aubyn Nixon (11 August 1850 – February 1913) was an Indian-born English cricketer who played first-class cricket for Middlesex, Cambridge University and a side representing the "Gentlemen of the South". He was born at Neermuck in the Rajputana, India and died at Lintlaw, Saskatchewan, Canada. The precise date of his death is not known.
Nixon was educated at Rossall School and matriculated at Trinity Hall, Cambridge in 1869; there is no evidence that he read for a degree at Cambridge University and from 1870 to 1897 he is recorded as being employed by the public works department of the Indian Civil Service in Bengal.
As a cricketer, Nixon was a right-handed batsman; he also kept wicket in some games and was a round-arm slow bowler, though he did not bowl in first-class matches. He made his first-class debut as a batsman for Middlesex in 1868 and the following year, again playing only as a batsman, he scored 54, his only innings of note, in a match against Surrey. At Cambridge in 1870, he was tried as a wicketkeeper in a single match against the Marylebone Cricket Club but made only one stumping; a week later, he was recalled to the Cambridge side during the match against the Gentlemen of England as a replacement for an ill player and, allowed to keep wicket, made four stumpings and took two catches. He did not play for Cambridge University again and a single further appearance for Middlesex and one for a Gentlemen of the South side, both also in the 1870 season, were his final matches in first-class cricket.


Elizabeth Johnson (pamphleteer)

Elizabeth Johnson, "née" Reynolds (8 July 1721 – 14 May 1800), was an English pamphleteer who attempted to win one of the rewards offered by the Longitude Act passed in 1714. Johnson and Jane Squire are the only two women known to have done so. It was not considered an appropriate subject for early modern women especially given its financial, maritime, and government dimensions.
Early background.
She was born to the Rev. Samuel Reynolds and his wife Theophilia in Plympton, Devon. Among her siblings was the acclaimed artist Sir Joshua Reynolds, who used her as a model for works which were widely copied in mezzotint. The two would later quarrel over Joshua's lack of piety and over her husband's precarious financial situation and eventual bankruptcy.
Their other siblings included the author Mary Palmer and painter Frances Reynolds.
Married life.
On 7 January 1753, Elizabeth Reynolds married William Johnson at St. Michael and All Angels in Great Torrington, Devon.
The marriage produced seven children before her spouse abandoned the family, leaving Elizabeth at least in part dependent on her literary endeavors.
Publications.
Johnson's religious pamphlets, beginning with "The Explication of the Vision to Ezekiel" in 1781, were written anonymously – likely to evade any criticism of women publishing or expressing religious ideas. One critic sarcastically commented on her earlier works in 1783: "As the intentions of this writer are pious, his facilities evidently disordered, and his lucubrations absolutely unintelligible, these three pamphlets must be exempted from criticism." William Johnson Cory later revealed the true identity of the pamphlets' author in a handwritten inscription on one of the Bodleian Library's copies of the "Ezekiel" pamphlet: "This strange book was written by my great-grandmother Mrs. Johnson, sister of Sir Joshua Reynolds. When extremely poor she posted up to Oxford to get it published, being a real enthusiast."
Longitude.
"The Astronomy and Geography of the Created World", her fourth pamphlet published in 1785, included a short reference to longitude. The pamphlet ended with the claim "that if the palm for finding the longitude, is not given to the author of the "Explanation of the Vision to Ezikiel" it will never be given to another". The modern attribution of the Ezekiel pamphlet to Johnson has only recently revealed that the author of the 1785 work was a rare female longitude-seeker, as she even remained anonymous when sending it to the Board of Longitude in 1786 in the hope of a reward. She was unsuccessful, and the pamphlet and letter were later catalogued by the Astronomer Royal George Airy in a volume of Board of Longitude correspondence which he entitled "Irrational Astronomical Theories" in 1858. However, it was not the only early modern pamphlet to address both religion and longitude.
Elizabeth Johnson died in Great Torrington, Devon in 1800.


Arthur Roberts (cricketer)

Arthur Wilson Roberts (23 September 1874 – 27 June 1961) was an English cricketer. Roberts was a right-handed batsman who bowled right-arm fast-medium. He was born in Malegaon, Bombay Presidency and later educated at Rossall School in Lancashire, England.
Roberts made his debut in county cricket for Oxfordshire in the 1896 Minor Counties Championship. He played a further match for Oxfordshire in the following season. He later appeared in 2 Minor Counties Championship matches for Buckinghamshire in 1902.
Roberts made his first-class debut for Gloucestershire against Hampshire in 1908 County Championship. He played 28 first-class matches for Gloucestershire, the last coming against Somerset in the 1913 County Championship. In those 28 first-class matches, he scored 727 runs at a batting average of 17.73, with a 3 half centuries and a high score of 90. His highest score came against Somerset in 1911. A part-time bowler, Roberts took 11 wickets for Gloucestershire at a bowling average of 36.00, with best figures of 2/20.
He also played a single first-class match for an England XI against Hambledon in a commemorative match at the Broadhalfpenny Down ground, home to the original Hambledon Club. In this match he was dismissed for 11 in the England XI's first-innings by Jack Newman, while in their second-innings he scored 69 runs before being dismissed by the same bowler. With the ball he took a single wicket, that of Guy Bignell.
He died in Hastings, Sussex on 27 June 1961. He survived his brother, Francis, who had also played first-class cricket but was killed in the First World War by 45 years.


Douglas Gough

Douglas Owen Gough FRS (born 8 February 1941) is a British astronomer, Professor Emeritus of Theoretical Astrophysics in the University of Cambridge, and Leverhulme Emeritus Fellow.
Life.
Gough was educated at Hackney Downs School before attending the University of Cambridge (St John's College) where he studied at the Department of Applied Mathematics and Theoretical Physics (DAMTP). He subsequently worked with John Cox at JILA (Colorado) from 1966 to 1967, at the Goddard Institute for Space Studies and with Edward Spiegel at the Courant Institute of Mathematical Sciences in New York from 1967 to 1969. He returned to Cambridge in 1969 to join the Institute of Theoretical Astronomy and DAMTP. He was Director of the Institute of Astronomy from 1999 to 2004, Deputy Director from 1993 to 1999. He has been a Fellow of Churchill College, Cambridge, since 1972, a Science Research Council Senior Fellow (1978–1983), a Fellow Adjoint of JILA since 1986, an Honorary Professor of Astronomy at Queen Mary and Westfield College, University of London (1986–2009), and a Visiting Professor of Physics (now Consulting Professor) at Stanford University since 1996.
He was appointed Distinguished Visiting Professor at the University of Mumbai in 2015.
He is a Fellow of the Royal Society, a Fellow of the Institute of Physics, a Foreign Member of the Royal Danish Academy of Sciences and Letters, and a Mousquetaire d'Armagnac. He is married to Rosanne; they have four children: Kim McCabe, Heidi Rose, Julian Gough and Russell Gough, and seven grandchildren.
Scientific work.
Gough began his career working mainly on the problem of convection in stars and how it interacts with stellar pulsations. His best known works from this period include the a criterion for the inhibition of convection by magnetic fields in stars, the application of the anelastic approximation to stellar atmospheres, and a model of convection that is the foundation of methods still used today to model the interaction of convection and pulsations in classical variable stars and in the Sun. In 1976, he and his PhD student Jørgen Christensen-Dalsgaard predicted that the global oscillation frequencies of the Sun could be used to infer its deep structure. This is regarded as the beginning of what became known as helioseismology and, by extension, asteroseismology of solar-like oscillators; Gough and Christensen-Dalsgaard are regarded as the "fathers" of the field. Gough and his students subsequently published extensively on the internal structure of the Sun and the calculation thereof, including determining features like the depth of the solar convection zone, the Sun's interior rotation, the protosolar helium abundance and the main-sequence age. He pioneered seismological investigation into the equation of state in the Sun and the helium abundance in stellar convection zones.
His doctoral students have included the Raja of Mahmudabad, Chris Jones, Douglas N. C. Lin, John Gribbin, Jørgen Christensen-Dalsgaard, Michael Thompson, Margarida Cunha, Marcus Brüggen and Pascale Garaud.


Battle of Quilacura

Battle of Quilacura was a battle in the Arauco War, fought at night, four leagues from the Bio-Bio River, between the Spanish expedition of Pedro de Valdivia and a force of Mapuche warriors led by Malloquete on February 11, 1546.


Roberson Museum and Science Center

The Roberson Museum and Science Center is located in Binghamton, New York. The museum's exhibits focus on art, local history, science and natural history.
The centerpiece of the museum is the 1904 Roberson Mansion, which was designed by local architect C. Edward Vosbury. More contemporary additions to the mansion were added in the 1960s and 1980s, which expanded the exhibit space, included a planetarium, added offices, and upgraded the vaults and collections preparation space.
The museum features changing exhibits and a large model train layout that depicts regional landscapes in the 1950s. The museum hosts annual special events, including decorating the Roberson Mansion for the Christmas holidays, a food and wine festival, Halloween activities, science fiction conventions, a model train and doll fair, and more.


Dust storms on Mars


Dark gravity


Neuseway Nature Center and Planetarium

The "Neuseway Nature Center and Planetarium" is a science center in Kinston, North Carolina. The facility includes 52 seat planetarium which also includes permanent exhibits focused on public health provided by Lenoir Memorial Hospital and an exhibit of space memorabilia donated by a former NASA engineer. A nature center includes exhibits of reptiles, fish and small mammals native to the area.
The planetarium participates in the North Carolina Science Festival each year hosting a star party for visitors.


Brown-dwarf desert

The brown-dwarf desert is a theorized range of orbits around a star on which brown dwarfs cannot exist as a companion object. This is usually up to 5 AU around solar mass stars. The paucity of brown dwarfs in close orbits was first noted between 1998–2000 when a sufficient number of extrasolar planets had been found to perform statistical studies. Astronomers discovered there is a distinct shortage of brown dwarfs within 5 AU of the stars with companions, while there was an abundance of free-floating brown dwarfs being discovered. Subsequent studies have shown that brown dwarfs orbiting within 3–5 AU are found around less than 1% of stars with a mass similar to the Sun (). Of the brown dwarfs that were found in the brown-dwarf desert, most were found in multiple systems, suggesting that binarity was a key factor in the creation of brown-dwarf desert inhabitants.
One of the many possible reasons for the existence of the desert relates to planetary (and brown dwarf) migration. If a brown dwarf were to form within 5 AU of its companion star, it could plausibly begin migrating inwards towards the central star and eventually fall into the star itself. That being said, the exact details of migration within a proto-planetary disk are not completely understood, and it is equally plausible that brown dwarf companions to FGK dwarfs would not undergo appreciable migration after their formation. A second possible reason is, depending on which formation paradigm is invoked, that a formation by core accretion should make the formation of higher mass brown dwarfs unlikely, as the gas accretion rate during runaway accretion onto high mass forming objects is reduced due to gap formation in the disk. The limited disk life time then truncates the mass range, limiting the maximum masses to approximately 10 Jupiter masses ().
This effect might be somewhat mitigated by the fact that objects of and above might excite eccentric perturbations in the disk, allowing for non-negligible mass accretion even in the presence of a gap.
Objects that form further outside (a>80 AU), where the disk is prone to gravitational instabilities, might be able to reach the masses required to cross the planet–brown dwarf threshold. For these objects it might be unlikely to migrate into the inner regions of the disk, however, due to the long type-II migration timescale for massive objects in the brown dwarf mass regime.


Chris Lintott

Christopher John Lintott (born 26 November 1980) is a British astrophysicist, author and broadcaster. He is a Professor of Astrophysics in the Department of Physics at the University of Oxford. Lintott is involved in a number of popular science projects aimed at bringing astronomy to a wider audience and is also the primary presenter of the BBC television series "The Sky at Night", having previously been co-presenter with Patrick Moore until Moore's death in 2012. He co-authored "Bang! – The Complete History of the Universe" and "The Cosmic Tourist" with Moore and Queen guitarist and astrophysicist Brian May.
Education.
Lintott attended Torquay Boys' Grammar School in Devon. In 1999, while still at school, he won a $500 Earth and Space Sciences award and the Priscilla and Bart Bok Honorable Mention Award at the Intel International Science and Engineering Fair for an article on 'Cosmic dust around young stellar objects'. This came from a six-week project at the University of Hertfordshire funded by a Nuffield bursary. He read Natural Sciences at Magdalene College, Cambridge and in 2006 received a PhD in astrophysics from University College London, for his thesis on the early stages of star formation supervised by Ofer Lahav.
Research and career.
 Lintott is co-director of the Programme on Computational Cosmology and Citizen Science Project Lead in the Department of Physics at the University of Oxford, and a Research Fellow of New College, Oxford. He was the Director of Citizen Science Initiatives at the Adler Planetarium from 2010 until 2012.
His research focuses on galaxy evolution and the application of astrochemical models of star formation to galaxies beyond the Milky Way; particularly the use of sulphur compounds as a signature of stars that are in the process of formation. After a recommendation from Ed Vaizey, former Culture Minister, Prime Minister David Cameron appointed Lintott as Astronomy Trustee of the National Maritime Museum (NMM). His appointment ran from 24 June 2010 until 23 June 2014.
Lintott's research has been published in a wide variety of peer-reviewed scientific journals. He was formerly a Fulford junior research fellow at Somerville College, Oxford between 2006 and 2010.
Lintott's research has been funded by the Engineering and Physical Sciences Research Council (EPSRC), the Arts and Humanities Research Council (AHRC) and the Science and Technology Facilities Council (STFC).
The Sky at Night.
Lintott first appeared on the BBC astronomy programme "The Sky at Night", presented by Patrick Moore, as a guest in 2000. As Moore's mobility deteriorated, Lintott acquired an increasingly prominent role, often providing on-location reporting from events covered by the programme. In an interview in 2007 with Mark Lawson, Moore described him as "eminently suitable" as a presenter. He jointly presented the programme with Moore until the latter's death in December 2012. Since the February 2013 episode, Chris Lintott has been a co-presenter with Lucie Green (until December 2013) and with Maggie Aderin-Pocock (since February 2014). In July 2004, Moore suffered a near-fatal bout of food poisoning and Lintott stood in as the sole presenter of that month's episode. It was the only episode which Moore did not present since the show was first broadcast on 24 April 1957 until his death.
Galaxy Zoo & The Zooniverse.
Chris Lintott is the co-founder, along with Kevin Schawinski, of Galaxy Zoo, an online crowdsourcing project where members of the public can volunteer their time to assist in classifying over a million galaxies.(e.g.) Lintott stated when commenting on GZ: "One advantage is that you get to see parts of space that have never been seen before. These images were taken by a robotic telescope and processed automatically, so the odds are that when you log on, that first galaxy you see will be one that no human has seen before." This was confirmed by Schawinski: "Most of these galaxies have been photographed by a robotic telescope, and then processed by computer. So this is the first time they will have been seen by human eyes."
Lintott is the principal investigator (P.I.) for the citizen science web portal Zooniverse. Quoting from the Zooniverse Team page: "Astronomer and founder of both Galaxy Zoo and the Zooniverse that grew from it, Chris is interested in how galaxies form and evolve, how citizen science can change the world". Lintott is also the chair of the Citizen Science Alliance, the organisation that produces, maintains and develops The Zooniverse.
Books.
In October 2006, Chris Lintott, Patrick Moore and Brian May co-authored a book entitled "Bang! – The Complete History of the Universe", which was produced by Canopus Books and published by Carlton Books on 23 October 2006. It has been translated into 13 languages and has appeared in paperback. As suggested by the title, the illustrated book is a history of the Universe from the Big Bang to its eventual predicted end. It is aimed at a popular science audience and claims to make its subject matter easily comprehensible to readers without any knowledge of astronomy.
In October 2012, Brian May, Patrick Moore and Chris Lintott co-authored a book entitled "The Cosmic Tourist: The 100 Most Awe-inspiring Destinations in the Universe". On the book's PR page, it is stated: "Take your seats for the greatest tour ever – one that encompasses no less than the whole of the Universe."
Chris Lintott's book, "The Crowd and the Cosmos: Adventures in the Zooniverse" was released in 2019.
Awards and honours.
Lintott is a Fellow of the Royal Astronomical Society. In 2011, Lintott was awarded the Royal Society Kohn Award. He was awarded this (quoting from the Royal Society webpage): "For his excellent engagement with society in matters of science and its societal dimension."
In 2013, Lintott was awarded the Oxford Internet Institute Internet and Society Award. He was given this (quoting from the OII website): "in recognition of Galaxy Zoo's outstanding contributions to research by using crowd-sourced citizen science to capitalise on the availability of online big data-sets."
In 2014, he received the Beatrice M. Tinsley Prize from the American Astronomical Society. He was awarded this (quoting from the AAS website): "For his insight and creativity that created a transformative approach to science by engaging nonscientists in cutting edge research."
In 2015, he won the Institute of Physics Kelvin Medal and Prize. In 2020 he was elected a Legacy Fellow of the American Astronomical Society.


York Minster astronomical clock

The York Minster astronomical clock is a memorial to the airmen operating from bases in Yorkshire, Durham, and Northumberland who were killed in action during World War II, designed by R. Atkinson, and installed in York Minster in 1955.
History.
The clock was first conceived in 1944 and designed by Robert d'Escourt Atkinson, chief assistant at the Royal Greenwich Observatory. Atkinson based the design on the appearance of the sun and stars from the viewpoint of a pilot flying over York. The mechanism and two dials were constructed by A.C.S. Westcott and Royal Greenwich Observatory craftsmen, and installed in the North Transept of York Minster in 1955.
Damage to the clock's mechanism was sustained during a fire, on 9 July 1984; after 10 years' work attempting reparation, vergers ceased winding, it owing to inaccuracies of time-keeping.
Display dials.
The front dial shows the locations of the sun and certain navigational stars as would be seen by a pilot flying south above York Minster. To locate his position, a fixed circular plate, about 62 cm (slightly over 2 feet) in diameter and slightly dished, carries a ground plan of the Minster and surrounding markings representative of city walls, rivers, and principal roads. Since the edge of the plate represents the effective horizon, its centre identifies the pilot's nadir.
Mounted behind the plate there is a star-planisphere, based on a north pole stereographic zenithal projection (a projection from the north pole onto a plane passing through the south pole, and perpendicular to the solar axis). This rotates once in a sidereal day on an axis passing through its south celestial pole and located some 13 cm above the centre of the horizon plate. For decoration it carries a few basic star patterns (considerably distorted owing to the projection used) and an eccentric zodiac / ecliptic / calendar ring faced with silver, and restricted in width to the distance between the solstitial points.
Associated with the ring is a rayed apparent-sun emblem whose supporting arm system moves to and fro relative to a main mean-motion arm by an amount corresponding to the equation of time, and also radially to represent changes in the sun's declination. Sun-emblem and horizon-plate therefore combine to show the times of the sun's rising, southing, and setting throughout the year and, by means of the rays of the sun emblem, the extent of the twilight.
To complete the front dial display, two sets of curved wires are mounted in front of the planisphere. One set of two wires indicates lines of equal altitude 36° and 59.5° and supplements the edge of the horizon plate (altitude 0°); they cross a vertical north-south wire to indicate the sun's meridian altitude at the equinoxes and solstices respectively. The second set, in addition to the north-south element, forms a complete circle and the sectors of two larger circles; all four wires intersect at the centre of the horizon plate (nadir) and a point near the top of the north-south line (zenith).
The rear planisphere, similar in size to the one in the front but strictly circular, displays the brightest stars of the main circumpolar constellations (Ursa Major, Ursa Minor, and Cassiopeia). It is centred on the north celestial pole and, with its encircling silvered ring of 24 hour intervals, rotates once a sidereal day relative to a fixed meridian-index.
Gearing.
The planisphere is attached to a large wheel driven by a worm gear, which is connected to a gear box containing the wheel-train. The gear wheels have ratios , , and , producing a solar to sidereal ratio of = : This produces an approximation for the mean tropical year of 365.24219447 days (compare to 365.24219265 days).
The worm gear serving the similar wheel of the mean-sun arm is connected to the input end of the gear box, and also, through a 3000:1 reduction gear, to a 1500  synchronous electric motor, running off the main electricity supply.
For the equation correction, a wheel on a lever associated with the mean solar arm rolls round an annular cam of sheet brass about 61 cm in diameter. Beneath the planisphere, three small dials show hours, minutes, and seconds of Greenwich Mean Time, and three similar and balancing dials give local sidereal time in degrees, minutes, and seconds of arc. An aperture indicates the name of the day of the week.


Drake Planetarium and Science Center

Drake Planetarium & Science Center is a 70-seat planetarium and science center located within Norwood High School in Norwood, Ohio, a city surrounded by Cincinnati. Drake Science Center is located on the first floor of Norwood Middle School. The facility is named after Dr. Frank Drake, in honor of his research on extra-terrestrial life.
The planetarium includes a 35-foot domed theater, featuring an analog Spitz system custom built in Germany, a high-definition full-dome projection system, and high efficiency LED flood lighting. The optical star projector and an immersive projection system produce a vibrant night sky and immersive full dome technology 180 degrees overhead. Programs are available for audiences ranging from preschool age to senior citizens, and for two months of the year, the Drake Planetarium also houses a laser projection system used for special programming.
Drake Planetarium & Science Center has been operated by Tri-State Education & Technology Foundation since 1982. This foundation is a nonprofit educational organization with the mission to provide STEM fields (science, technology, engineering, and mathematics) learning experiences for the youth of Greater Cincinnati.


Albert Curtz

Albert Curtz ("Curtius" in Latin; 1600, Munich – December 19, 1671, Munich), was a German astronomer and member of the Society of Jesus. He expanded on the works of Tycho Brahe and used the pseudonym of "Lucius Barrettus".
Background.
The Latin version of the name Albert Curtz, Albertus Curtius is an anagram of his pseudonym, Lucius Barretus.
Together with Johann Deckers, Kepler, Francesco Maria Grimaldi, and Jean-Baptiste Riccioli, he contributed to our early understanding of the Moon.
He published "Historia coelestis [ex libris commentariis manuscriptis observationum vicennalium viri generosi Tichonis Brahe"] and "Augustae Vindelicorum, Simonem Utzschneiderum" in 1666.
The crater Curtius on the Moon was named after him.


John Evershed

John Evershed CIE FRS FRAS (26 February 1864 – 17 November 1956) was an English astronomer. He was the first to observe radial motions in sunspots, a phenomenon now known as the Evershed effect.
Biography.
Evershed was born in Gomshall, Surrey to John and Sophia (née Price) Evershed. He made the discovery which bears his name while at Kodaikanal Observatory in 1909. After retirement in 1923 he set up a private observatory at Ewhurst, Surrey and built a large spectroheliograph of special design and another with high-dispersion liquid prism. He continued to study the wave-lengths of H and K lines in prominences, giving values of the solar rotation at high levels in different latitudes and at different phases of the solar cycle. Work continued until 1950 when the observatory closed and he presented some of his instruments to the Royal Greenwich Observatory at Herstmonceux. In the autumn of 1890 was a founding member of the British Astronomical Association. He directed its Solar Spectroscopy Section (1893-1899) and Spectroscopic Section (1924-1926).
Awards and honours.
In 1894 Evershed was elected a Fellow of the Royal Astronomical Society, in 1918 he was awarded the Gold Medal of the Royal Astronomical Society. He was elected a Fellow of the Royal Society in May, 1915. The Evershed crater on the Moon is named in his honor. He was awarded as a Companion of the Indian Empire on his retirement in 1923.
Personal life.
Evershed was married to fellow astronomer Mary Acworth Orr Evershed, with whom he co-authored some work. He died in Ewhurst, Surrey on 17 November 1956.
He also had interest in lepidoptera and other insects. W. H. Evans described a butterfly and named it after Evershed(Thoressa evershedi-Evans, 1910) as the first specimen was collected by Evershed. In 2015 his archive was acquired by the Science Museum, London.
Bibliography.
Monthly Notices of the Royal Astronomical Society
Nature
Journal of the British Astronomical Association,
The Observatory


Herbert Dingle

Herbert Dingle (2 August 1890 – 4 September 1978) was an English physicist and philosopher of science, who served as president of the Royal Astronomical Society from 1951 to 1953. He is best known for his opposition to Albert Einstein's special theory of relativity and the protracted controversy that this provoked.
Biography.
Dingle was born in London, but spent his early years in Plymouth, where he was taken following the death of his father, and where he attended Plymouth Science, Art and Technical Schools. Due to lack of money, he left school at the age of 14 and found employment as a clerk, a job which he held for 11 years. At age 25 he won a scholarship to the Imperial College, London, from which he graduated in 1918. In that same year, Dingle married Alice Westacott who later gave birth to a son. As a Quaker, Dingle was exempt from military service during World War I. He took a position as a Demonstrator in the Physics Department, and devoted himself to the study of spectroscopy (following his mentor Alfred Fowler), especially its applications in astronomy. He was elected a Fellow of the Royal Astronomical Society in 1922.
Dingle was a member of the British government eclipse expeditions of 1927 (Colwyn Bay) and 1932 (Montreal), both of which failed to make any observations due to overcast skies. He spent most of 1932 at the California Institute of Technology as a Rockefeller Foundation Scholar. There he met the theoretical cosmologist R. C. Tolman, and studied relativistic cosmology.
Dingle became a professor of Natural Philosophy at Imperial College in 1938, and was a professor of History and Philosophy of Science at University College London from 1946 until his retirement in 1955. Thereafter he held the customary title of Professor Emeritus from that institution. He was one of the founders of the British Society for the History of Science, and served as President from 1955 to 1957. He founded what later became the British Society for the Philosophy of Science as well as its journal, the "British Journal for The Philosophy of Science".
Dingle was the author of "Modern Astrophysics" (1924) and "Practical Applications of Spectrum Analysis" (1950). He also wrote the essay "Relativity for All" (1922) and the monograph "The Special Theory of Relativity" (1940). A collection of Dingle's lectures on the history and philosophy of science was published in 1954. He also took an interest in English literature, and published "Science and Literary Criticism" in 1949, and "The Mind of Emily Brontë" in 1974.
Controversies.
Dingle participated in two very public scientific controversies. The first of these took place during the 1930s and was triggered by Dingle's criticism of E. A. Milne's cosmological model and the associated theoretical methodology, which Dingle considered overly speculative and not based on empirical data. A. S. Eddington was another target of Dingle's criticism, and the ensuing debate eventually involved nearly every prominent astrophysicist and cosmologist in Britain. Dingle characterized his opponents as "traitors" to the scientific method, and called them "the modern Aristotelians" because he believed their theorizing was based on rationalism rather than empiricism. Some other scientists, notably Willem de Sitter, while not endorsing Dingle's more extreme rhetoric, nevertheless agreed with Dingle that the cosmological models of Milne, Eddington, and others were overly speculative. However, most modern cosmologists subsequently accepted the validity of the hypothetico-deductive method of Milne.
The second dispute began in the late 1950s, following Dingle's retirement and centered on the theory of special relativity.
Initially Dingle argued that, contrary to the usual understanding of the famous twin paradox, special relativity did not predict unequal aging of twins, one of whom makes a high-speed voyage and returns to Earth. However, Dingle then came to realize and acknowledge that his understanding of the problem had been mistaken. He then began to argue that special relativity was empirically wrong in its predictions, although experimental evidence showed he was mistaken about this. Ultimately, Dingle re-focused his criticism to claim that special relativity was logically inconsistent, declaring that special relativity "unavoidably requires that A works more slowly than B and B more slowly than A — which it requires no super-intelligence to see is impossible." Hence he asserted that the well-known reciprocity of the Lorentz transformation is self-evidently impossible. As Whitrow explained in his obituary for Dingle, this is not correct, as it rests on Dingle's mistaken assumption that the conflicting ratios of event times used by Dingle are invariants.
Dingle carried on a highly public and contentious campaign to get this conclusion accepted by the scientific community, mostly through letters to the editors of various scientific periodicals, including "Nature". Dozens of scientists responded with answers to Dingle's claims, explaining why the reciprocity of the Lorentz transformation does not entail any logical inconsistency, but Dingle rejected all the explanations. This culminated in his 1972 book, "Science at the Crossroads" in which Dingle stated that "a proof that Einstein's special theory of relativity is false has been advanced; and ignored, evaded, suppressed and, indeed, treated in every possible way except that of answering it, by the whole scientific world." He also warned: "Since this theory is basic to practically all physical experiments, the consequences if it is false, modern atomic experiments being what they are, may be immeasurably calamitous."
The consensus in the physics community is that Dingle's objections to the logical consistency of special relativity were unfounded. According to Max Born, "Dingle's objections are just a matter of superficial formulation and confusion."


Henry Lawson (astronomer)

Henry Lawson (1774–1855) was an English astronomer, member of the Royal Astronomical Society, the Royal Society, and the British Meteorological Society, as well as an inventor, designer, science educator, and philanthropist. He observed an occultation of Saturn on 8 May 1832, Johann Gottfried Galle's first comet in December 1839 and January 1840, and recorded the falling stars of 12–13 November 1841. He claimed to have been related to Catherine Parr.
Life.
He was the second son of Johnson Lawson, dean of Battle, Sussex, and Elizabeth, daughter of Henry Wright of Bath, Somerset, he was born at Greenwich on 23 March 1774. He was a pupil of Charles Burney, and then entered as an apprentice the optical establishment of his stepfather Edward Nairne of Cornhill. Subsequently, he did not go into in business, but concentrated on scientific study. He had been apprenticed through and, like Nairne, became a Freeman of the Worshipful Company of Spectacle Makers. He became Master of the Company in 1803-04 and 1822–23. He was responsible for redesigning the company's unofficial arms in 1810, incorporating scientific instruments as well as spectacles.
Living in Hereford after his 1823 marriage, he equipped an observatory with a five-foot refractor in 1826, and with one of eleven feet in 1834, made by George Dollond. A relative having left him a fortune, he moved to Bath in 1841, and mounted his instruments on the roof of his house at No. 7 Lansdown Crescent.
Lawson devoted time to promoting science for young people, and dispensing charity. He died at Bath in his eighty-second year, a few weeks after his wife, on 22 August 1855, and was buried at Weston.
Legacy.
The last of his line of the family, Lawson bequeathed to Agnes Strickland relics of his supposed ancestress Catherine Parr. His large fortune was divided by will among 139 persons, and some charitable institutions. Lawson became a member of the Royal Astronomical Society in 1833, of the Royal Society in 1840, and of the British Meteorological Society in 1850, and left money to each of those bodies.
Lawson had offered in December 1851 his astronomical apparatus, with 1000 guineas, to the town of Nottingham, on condition of money enough being raised to build and endow an observatory. The plan failed after disputes about the valuation of the instruments. His eleven-foot telescope was later presented to the Royal Hospital School at Greenwich, the five-foot to William Garrow Lettsom, and his meteorological appliances to Edward Joseph Lowe.
Works.
Lawson observed an occultation of Saturn on 8 May 1832, Johann Gottfried Galle's first comet in December 1839 and January 1840, and recorded the falling stars of 12–13 November 1841. He published in 1844 a paper "On the Arrangement of an Observatory for Practical Astronomy and Meteorology", and in 1847 a brief "History of the New Planets."
The Society of Arts, of which he was a member, voted Lawson a silver medal for the invention of an observing-chair called "Reclinea", and awarded him a prize for a new thermometer-stand, described before the British Association in 1845. He made communications to the British Association in 1846 and 1847 on solar telescopic work, and published in 1853 accounts of his designs for a "lifting apparatus" for invalids, and of a "surgical transferrer".
Family.
Lawson lived with his mother until her death in 1823, when he married Amelia, daughter of Thomas Jennings, vicar of St. Peter's, Hereford.
Notes.
Attribution


List of astronomical societies

A list of notable groups devoted to promoting astronomy research and education.


Arabia quadrangle

The Arabia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Arabia quadrangle is also referred to as MC-12 (Mars Chart-12).
The quadrangle contains part of the classic area of Mars known as Arabia. It also contains a part of Terra Sabaea and a small part of Meridiani Planum. It lies on the boundary between the young northern plains and the old southern highlands. The quadrangle covers the area from 315° to 360° west longitude and 0° to 30° north latitude.
Description.
The surface of the Arabia quadrangle appears to be very old because it has a high density of craters, but it is not near as high in elevation as typical old surfaces. On Mars the oldest areas contain the most craters; the oldest period is called Noachian after the quadrangle Noachis. The Arabia area contains many buttes and ridges. Some believe that during certain climate changes an ice-dust layer was deposited; later, parts were eroded to form buttes.
Some outflow channels are found in Arabia, namely Naktong Vallis, Locras Valles, Indus Vallis, Scamander Vallis, and Cusus Valles.
Layers.
Many places in Arabia are shaped into layers. The layers can be a few meters thick or tens of meters thick. Recent research on these layers by scientists at California Institute of Technology (Caltech) suggest that ancient climate change on Mars caused by regular variation in the planet's tilt, or obliquity may have caused the patterns in the layers. On Earth, similar changes (astronomical forcing) of climate results in ice-age cycles.
A recent study of layers in craters in western Arabia revealed much about the history of the layers. Although the craters in this study are just outside the boundary for the Arabia quadrangle the findings would probably apply to the Arabia quadrangle as well. The thickness of each layer may average less than 4 meters in one crater, but 20 meters in another. The pattern of layers measured in Becquerel crater, suggests that each layer was formed over a period of about 100,000 years. Moreover, every 10 layers were bundled together into larger units. The 10-layer pattern is repeated at least 10 times. So every 10-layer pattern took one-million years to form.
The tilt of the Earth's axis changes by only a little more than 2 degrees; it is stabilized by the relatively large mass of our moon. In contrast Mars's tilt varies by tens of degrees. When the tilt (or obliquity) is low, the poles are the coldest places on the planet, while the equator is the warmest—as on Earth. This causes gases in the atmosphere, like water and carbon dioxide, to migrate pole ward, where they freeze. When the obliquity is higher, the poles receive more sunlight, causing those materials to migrate away. When carbon dioxide moves from the poles, the atmospheric pressure increases, maybe causing a difference in the ability of winds to transport and deposit sand. Also, with more water in the atmosphere sand grains may stick and cement together to form layers. This study of the thickness of layers was done using stereo topographic maps obtained by processing data from the high-resolution camera onboard NASA's Mars Reconnaissance Orbiter.
Recent research leads scientists to believe that some of the craters in Arabia may have held huge lakes. Cassini Crater and Tikonravov Crater probably once were full of water since their rims seem to have been breached by water. Both inflow and outflow channels have been observed on their rims. Each of these lakes would have contained more water than Earth's Lake Baikal, our largest freshwater lake by volume. The watersheds for lakes in Arabia seem to be too small to gather enough water by precipitation alone; therefore it is thought that much of their water came from groundwater.
Another group of researchers proposed groundwater with dissolved minerals came to the surface, in and later around craters, and helped to form layers by adding minerals (especially sulfate) and cementing sediments. Upon close examination, Arabia layers appear to have a slight tilt. This tilt supports formation with the action of a rising water table. A water table generally follows the topography. Since the layers slope slightly down toward the northwest, the layers may have been created by groundwater, rather than a single large sea that has been suggested.
This hypothesis is supported by a groundwater model and by sulfates discovered in a wide area. At first, by examining surface materials with Opportunity Rover, scientists discovered that groundwater had repeatedly risen and deposited sulfates. Later studies with instruments on board the Mars Reconnaissance Orbiter showed that the same kinds of materials exist in a large area that included Arabia.
Light-toned materials.
Certain areas of Mars show ground that has a much lighter-tone than most other areas. Much of the surface of Mars is dark because of extensive flows of the dark lave rock basalt. Studies with spectroscopes from orbit have shown that many light-toned areas contain hydrated minerals, and/or clay minerals. That means that water was once there in order to produce these substances. In short, light-toned materials are markers for the past presence of water.
Craters.
Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact. Sometimes craters display layers. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed unto the surface. Hence, craters can show us what lies deep under the surface.
Some craters in Arabia are classified as pedestal craters. A pedestal crater is a crater with its ejecta sitting above the surrounding terrain and thereby forming a raised platform. They form when an impact crater ejects material which forms an erosion resistant layer, thus protecting the immediate area from erosion. As a result of this hard covering, the crater and its ejecta become elevated, as erosion removes the softer material beyond the ejecta. Some pedestals have been accurately measured to be hundreds of meters above the surrounding area. This means that hundreds of meters of material were eroded away. Pedestal craters were first observed during the Mariner missions.
Researchers believe over 200 new craters are formed each year on Mars, based on study of years of HiRISE images.
Possible methane.
One study with the Planetary Fourier Spectrometer in the Mars Express spacecraft found possible methane in three areas of Mars, one of which was in Arabia. One possible source of methane is from the metabolism of living bacteria. However, a recent study indicates that to match the observations of methane, there must be something that quickly destroys the gas, otherwise it would be spread all through the atmosphere instead of being concentrated in just a few locations. There may be something in the soil that oxidizes the gas before it has a chance to spread. If this is so, that same chemical would destroy organic compounds, thus life would be very difficult on Mars.
Deformation bands.
The Mars Reconnaissance Orbiter showed deformation bands in Capen Crater, located in the Arabia quadrangle. Deformation bands are small faults with very small displacements. They often proceed large faults. They develop in porous rocks, like sandstone. They can restrict and/or change the flow of fluids like water and oil. They are common in the Colorado Plateau. Good examples form in the Entrada Sandstone in the San Rafael Swell in Utah. The bands represent failure by localized frictional sliding. The bands on Mars are a few meters wide and up to a few kilometers long. They are caused by the compression or stretching of underground layers. Erosion of overlying layers make them visible at the surface. Capen Crater was unnamed before the discovery of deformation bands. It was named for Charles Capen, who studied Mars at JPL's Table Mountain Observatory in California and at Lowell Observatory in Arizona.
Geological history.
Recent studies, reported in the journal Icarus, have suggested that the area underwent several phases in its formation:
Dark slope streaks.
Streaks are common on Mars. They occur on steep slopes of craters, troughs, and valleys. The streaks are dark at first. They get lighter with age. Sometimes they start in a tiny spot, then spread out and go for hundreds of meters. They have been seen to travel around obstacles, like boulders. It is believed that they are avalanches of bright dust that expose a darker underlying layer. However, several ideas have been advanced to explain them. Some involve water or even the growth of organisms. Streaks appear in areas covered with dust. Much of the Martian surface is covered with dust. Fine dust settles out of the atmosphere covering everything. We know a lot about this dust because the solar panels of the Mars Rovers get covered with dust, thus reducing the electrical energy. The power of the Rovers has been restored many times by the wind, in the form of dust devils, cleaning the panels and boosting the power. So, we know that dust settles from the atmosphere then returns over and over. Dust storms are frequent, especially when the spring season begins in the southern hemisphere. At that time, Mars is 40% closer to the sun. The orbit of Mars is much more elliptical then the Earth's. That is the difference between the farthest point from the sun and the closest point to the sun is very great for Mars, but only a slight amount for the Earth. Also, every few years, the entire planet is engulfed in global dust storms. When NASA's Mariner 9 craft arrived there, nothing could be seen through the dust storm. Other global dust storms have also been observed, since that time.
Research, published in January 2012 in Icarus, found that dark streaks were initiated by airblasts from meteorites traveling at supersonic speeds. The team of scientists was led by Kaylan Burleigh, an undergraduate at the University of Arizona. After counting some 65,000 dark streaks around the impact site of a group of 5 new craters, patterns emerged. The number of streaks was greatest closer to the impact site. So, the impact somehow probably caused the streaks. Also, the distribution of the streaks formed a pattern with two wings extending from the impact site. The curved wings resembled scimitars, curved knives. This pattern suggests that an interaction of airblasts from the group of meteorites shook dust loose enough to start dust avalanches that formed the many dark streaks. At first it was thought that the shaking of the ground from the impact caused the dust avalanches, but if that was the case the dark streaks would have been arranged symmetrically around the impacts, rather than being concentrated into curved shapes.
Dark slope streaks can be caused by nearby impacts, as seen in the following HiRISE image of a new small impact that set off a slope streak.
Linear ridge networks.
Linear ridge networks are found in various places on Mars in and around craters. Ridges often appear as mostly straight segments that intersect in a lattice-like manner. They are hundreds of meters long, tens of meters high, and several meters wide. It is thought that impacts created fractures in the surface, these fractures later acted as channels for fluids. Fluids cemented the structures. With the passage of time, surrounding material was eroded away, thereby leaving hard ridges behind.
Since the ridges occur in locations with clay, these formations could serve as a marker for clay which requires water for its formation. Water here could have supported past life in these locations. Clay may also preserve fossils or other traces of past life.


Fesenkov Astrophysical Institute

Fesenkov Astrophysical Institute (Астрофизический институт имени В. Г. Фесенкова, АФИФ), or FAPHI, is a research institute in Almaty, Kazakhstan. The institute was founded in 1941 as the Institute for Astronomy and Physics of the Kazakh branch of the USSR Academy of Sciences, when a group of Soviet astronomers was evacuated during World War II from the European parts of the USSR to Almaty. In 1948 G.A. Tikhov had organized an independent sector of astrobotany, and in 1950 astronomers established the Astrophysical Institute of the Kazakh SSR. In 1989 the Institute was renamed after Vasily Fesenkov, one of its founders.
FAPHI conducts both observational and theoretical research. The prime objects of observations are the Sun, outer planets, comets, Herbig Ae/Be stars, and active galaxies. The topics of theoretical research include stellar dynamics and computational astrophysics, active galactic nuclei, cosmology, physics of comets and interstellar medium. The institute runs three observational bases in mountains near Almaty: Kamenskoe Plateau Observatory, Assy-Turgen Observatory and Tien Shan Astronomical Observatory.
FAPHI is a member of the International Astronomical Union.


March 2006 lunar eclipse

A penumbral lunar eclipse took place on March 14, 2006, the first of two lunar eclipses in 2006.
This was a relatively rare total penumbral lunar eclipse with the moon passing entirely within the penumbral shadow without entering the darker umbral shadow. The tables below contain detailed predictions and additional information on the Penumbral Lunar Eclipse of 14 March 2006.
Visibility.
It was completely visible over Africa and Europe, seen rising over eastern North America, all of South America, and setting over western Asia.
<BR>A simulated view of the earth from the center of the moon at maximum eclipse.
Relation to other lunar eclipses.
Saros series.
The eclipse belongs to Saros series 113, and is the 63rd of 71 lunar eclipses in the series. The first penumbral eclipse of saros cycle 113 began on April 29, 888 AD, first partial eclipse on July 14, 1014, and total first was on March 20, 1429. The last total eclipse occurred on August 7, 1645, last partial on February 21, 1970, and last penumbral eclipse on June 10, 2150.
Half-Saros cycle.
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse is related to two total solar eclipses of Solar Saros 120.
Eclipse season.
This is the first eclipse this season.
Second eclipse this season: 29 March 2006 Total Solar Eclipse


Nightfall (2000 film)

Nightfall is a 2000 American straight-to-video science-fiction thriller film directed by Gwyneth Gibby and loosely based on Isaac Asimov's short story of the same name. The film stars Jennifer Burns, Winsome Brown, Joseph Hodge, David Carradine and Ashish Vidyarthi in the lead roles.


Photosphere

The photosphere is a star's outer shell from which light is radiated.
The term itself is derived from Ancient Greek roots, φῶς, φωτός/"phos, photos" meaning "light" and σφαῖρα/"sphaira" meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered.
A photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths.
Temperature.
The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface.
Composition of the Sun.
The Sun is composed primarily of the chemical elements hydrogen and helium; they account for 74.9% and 23.8% of the mass of the Sun in the photosphere, respectively. All heavier elements, called metals in astronomy, account for less than 2% of the mass, with oxygen (roughly 1% of the Sun's mass), carbon (0.3%), neon (0.2%), and iron (0.2%) being the most abundant.
Sun.
The Sun's photosphere has a temperature between (with an effective temperature of ) and a density of about 3 kg/m3; increasing with depth into the sun. Other stars may have hotter or cooler photospheres. The Sun's photosphere is around 100 kilometers thick, and is composed of convection cells called granules—cells of plasma each approximately 1000 kilometers in diameter with hot rising plasma in the center and cooler plasma falling in the narrow spaces between them, flowing at velocities of 7 kilometer per second. Each granule has a lifespan of only about twenty minutes, resulting in a continually shifting "boiling" pattern. Grouping the typical granules are super granules up to 30,000 kilometers in diameter with lifespans of up to 24 hours and flow speeds of about 500 meter per second, carrying magnetic field bundles to the edges of the cells. Other magnetically-related phenomena include sunspots and solar faculae dispersed between the granules. These details are too fine to be seen when observing other stars from earth.
Other layers of the Sun.
The Sun's visible atmosphere has other layers above the photosphere: the 2,000 kilometer-deep chromosphere (typically observed by filtered light, for example H-alpha) lies just between the photosphere and the much hotter but more tenuous corona. Other "surface features" on the photosphere are solar flares and sunspots.


Johann Heinrich Westphal

Johann Heinrich Westphal (January 31, 1794 – 1831) was a German astronomer. Not to be confused with J. G. Westphal, who discovered the lost periodic comet 20D/Westphal in 1852.
He was born in Schwerin. His professional career was spent mostly in Italy. He translated Giuseppe Piazzi's "Lezioni elementari di astronomia ad use del real osservatorio di Palermo" into German. He died in Sicily.


Meg Urry

Claudia Megan "Meg" Urry is an American astrophysicist, who was from 2015–2016 the President of the American Astronomical Society, formerly on the Hubble Space Telescope faculty and was chair of the Department of Physics at Yale University 2007–2013. She is notable not only for her contributions to astronomy and astrophysics, including work on black holes and multiwavelength surveys, but also for her work addressing sexism and gender equity in astronomy, and science and academia more generally.
Early life and education.
After growing up in Indiana and Massachusetts, Urry attended college at Tufts University, double-majoring in mathematics, music and physics, and graduating in 1977.
Urry earned an M.S. (1979) and a Ph.D. (1984) in physics from Johns Hopkins, where her advisor was Art Davidsen. For her dissertation, she studied blazars at Goddard Space Flight Center with Richard Mushotzky. She then conducted a postdoctorate at M.I.T.'s Center for Space Research, working with Claude Canizares. Urry joined Yale's faculty in 2001, at that time as the only woman in the department, and became Chair in 2007.
Career.
Urry has been active in addressing gender inequities in astronomy and science more generally, giving more than 60 talks on the topic, including at the annual Conferences for Undergraduate Women in Physics (CUWiP). With Laura Danly, Urry co-organized the first meeting of Women in Astronomy.
Urry studies supermassive black holes, known as Active Galactic Nuclei (AGN), and the relationship of normal galaxies to AGNs.


James W. Head

James W. Head III is the Louis and Elizabeth Scherck Distinguished Professor of Geological Sciences at Brown University. He studies the roles of volcanism in planetary crusts as well as the geological evolution of Mars, and has served as the investigator on many major international planetary investigation missions.
He earned his B.S. from Washington and Lee University in 1964 and his Ph.D. from Brown University in 1969. He spent 4 years with Bellcomm, Inc in Washington, DC where he helped train Apollo astronauts under the NASA Apollo Lunar Exploration Program.
He has published 25 chapters in books on planetary geology and over 300 refereed articles in scientific journals, and has supervised nearly 40 PhD students.


Internal structure of the Moon

Having a mean density of 3,346.4 kg/m3, the Moon is a differentiated body, being composed of a geochemically distinct crust, mantle, and planetary core. This structure is believed to have resulted from the fractional crystallization of a magma ocean shortly after its formation about 4.5 billion years ago. The energy required to melt the outer portion of the Moon is commonly attributed to a giant impact event that is postulated to have formed the Earth-Moon system, and the subsequent reaccretion of material in Earth orbit. Crystallization of this magma ocean would have given rise to a mafic mantle and a plagioclase-rich crust.
Geochemical mapping from orbit implies that the crust of the Moon is largely anorthositic in composition, consistent with the magma ocean hypothesis. In terms of elements, the lunar crust is composed primarily of oxygen, silicon, magnesium, iron, calcium, and aluminium, but important minor and trace elements such as titanium, uranium, thorium, potassium, and hydrogen are present as well. Based on geophysical techniques, the crust is estimated to be on average about 50 km thick.
Partial melting within the mantle of the Moon gave rise to the eruption of mare basalts on the lunar surface. Analyses of these basalts indicate that the mantle is composed predominantly of the minerals olivine, orthopyroxene and clinopyroxene, and that the lunar mantle is more iron-rich than that of the Earth. Some lunar basalts contain high abundances of titanium (present in the mineral ilmenite), suggesting that the mantle is highly heterogeneous in composition. Moonquakes have been found to occur deep within the mantle of the Moon about 1,000 km below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth. A few shallow moonquakes with hypocenters located about 100 km below the surface have also been detected, but these occur more infrequently and appear to be unrelated to the lunar tides.
Core.
Several lines of evidence imply that the lunar core is small, with a radius of about 350 km or less. The size of the lunar core is only about 20% the size of the Moon itself, in contrast to about 50% as is the case for most other terrestrial bodies. The composition of the lunar core is not well constrained, but most believe that it is composed of metallic iron alloy with a small amount of sulfur and nickel. Analyses of the Moon's time-variable rotations indicate that the core is at least partly molten.
In 2010, a reanalysis of the old Apollo seismic data on the deep moonquakes using modern processing methods confirmed that the Moon has an iron rich core with a radius of . The same reanalysis established that the solid inner core made of pure iron has a radius of . The core is surrounded by the partially (10 to 30%) melted layer of the lower mantle with a radius of (thickness ~150 km). These results imply that 40% of the core by volume has solidified. The density of the liquid outer core is about 5 g/cm3 and it could contain as much 6% sulfur by weight. The temperature in the core is probably about 1600–1700 K (1330–1430 °C).
In 2019, a reanalysis of nearly 50 years of data collected from the Lunar Laser Ranging experiment with lunar gravity field data from the GRAIL mission, shows that for a relaxed lunar fluid core with non-hydrostatic lithospheres, the core flattening is determined as with the radii of its core-mantle boundary as .


Somak Raychaudhury

Somak Raychaudhury () is an Indian astrophysicist. He is the Director of the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune. He is on leave from Presidency University, Kolkata, India, where he is a Professor of Physics, and is also affiliated to the University of Birmingham, United Kingdom. He is known for his work on stellar mass black holes and supermassive black holes. His significant contributions include those in the fields of gravitational lensing, galaxy dynamics and large-scale motions in the Universe, including the Great Attractor.
Education.
Somak Raychaudhury was born in Kolkata (then Calcutta), India. He attended St Xavier's Collegiate School, Kolkata, from which he ranked second in the Madhyamik examination of the West Bengal Board of Secondary Education, 1977. He then studied at St Xavier's College, Kolkata, from which he placed second in the state in the Higher Secondary Examination of the West Bengal Council of Higher Secondary Education. He attended Presidency College, Calcutta, where he completed his BSc degree in Physics in 1983. He then went to complete a BA degree in Physics at Trinity College, Oxford, University of Oxford, supported by an Inlaks Scholarship from the Inlaks Shivdasani Foundation, where he won a Douglas Sladen Essay prize. He then proceeded to obtain a PhD in Astrophysics from the University of Cambridge, United Kingdom, as a member of Churchill College, Cambridge, in 1990, supported by an Isaac Newton Studentship. Here, he was a recipient of a Smith's Prize (J.T. Knight Prize) in 1988. The subject of his doctoral thesis, supervised by Donald Lynden-Bell, FRS, was "Gravity, Galaxies and the 'Great Attractor' Survey".
Career.
Somak Raychaudhury became the fourth Director of the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune India, in September 2015. He was Professor and Head of Physics at Presidency University, Kolkata, where he was also the Dean of the Faculty of Natural and Mathematical Sciences till August 2015. He remains affiliated to the Astrophysics and Space Research group, School of Physics and Astronomy, University of Birmingham, where he used to be the director of the Wast Hills Observatory for the period 2003–2012. Prior to this, he was a member of the faculty at the Inter-University Centre for Astronomy and Astrophysics, Pune, India. He was a staff member at the Harvard–Smithsonian Center for Astrophysics, in Cambridge, Massachusetts, working for the Chandra X-ray Observatory. Before this, He was a Smithsonian postdoctoral fellow at the Harvard–Smithsonian Center for Astrophysics, and a tutor at Lowell House, Harvard University. Following his PhD, he was a SERC Research Fellow at the Institute of Astronomy, at the University of Cambridge, Cambridge, and a resident Junior Research fellow at St. Edmund's College, University of Cambridge.
Raychaudhury's research interests lie in the study of the evolution of galaxies in groups and clusters, and on the supercluster filaments of the cosmic web. He has used optical, X-ray, radio, infrared and ultraviolet observations to understand how the transformations of galaxies are related to their local and global environment. He is involved in developing machine learning algorithms for Astronomical data mining. He has published over 80 research
papers in peer-reviewed scientific journals on these themes. In addition, he leads a substantial outreach programme involving school students, teachers and the general public. He was one of the key people to start the Indian Astronomy Olympiad, and selected and coached the Indian Olympiad team to top results at the International Astronomy Olympiad in 1999 and 2000
. His outreach activities include numerous programmes on radio, television and collaboration with performing artists.
He is a member of the International Astronomical Union, a Fellow of the Royal Astronomical Society, and a Fellow of the European Astronomical Society. He is a Life Member of the Astronomical Society of India, and was an elected member of its Executive Council during 1998–2000.


Strasenburgh Planetarium

The Strasenburgh Planetarium is a public planetarium located at 663 East Avenue in the city of Rochester, New York. It is named after its benefactors, Edwin and Clara Strasenburgh. It is a department of the Rochester Museum and Science Center. The Planetarium was dedicated on September 14, 1968. The 65-foot-diameter Star Theater originally seated 240 people. The original seats were replaced in 1985; as currently configured, the theater seats 225. The Star Theater houses the first Zeiss Mark VI planetarium projector; it is still in daily operation. The planetarium received world-wide attention by being the first to be computer automated. It was known for both its technical and programming innovations.
History.
In 1935, soon after the opening of major planetariums in Chicago, Philadelphia, New York and Los Angeles, Arthur C. Parker, Director of the Rochester Museum of Arts and Sciences (predecessor to today's Rochester Museum & Science Center), recommended construction of a planetarium in Rochester.
In 1959, the Rochester Museum Association Planning Committee announced a master plan for expansion of the museum. An architectural design by Robert Napier, then a student at the Pratt Institute in Brooklyn, NY, included a detached planetarium building at the corner of East Avenue and Goodman Street, just west of the main Museum building. The conceptual plan also included a separate auditorium and a building for industry-related exhibits. None of these was actually constructed.
In the fall of 1964 the Rochester Museum of Arts and Sciences announced that it had received a gift of "more than one million dollars" from Mr. and Mrs. Edwin G. Strasenburgh of Rochester for the purpose of building a planetarium. The building design, by Carl F. W. Kaelber Jr. of the Rochester architectural firm of Waasdorp, Northup & Kaelber, was announced on June 28, 1966. In contrast to the 1959 concept, Kaelber's design placed the Strasenburgh Planetarium on the east side of the original Museum building. The Planetarium building was said to resemble a snail shell or a spiral nebula.
Construction began with a groundbreaking ceremony on March 16, 1967. The building was dedicated on September 14, 1968.


WASP-4b

WASP-4b is an extrasolar planet approximately 891 light-years away in the constellation of Phoenix.
Discovery.
The planet was the discovered by the Wide Angle Search for Planets team using images taken with the SuperWASP-South projects eight wide-angle cameras located at the South African Astronomical Observatory. Analysis of over 4000 images taken between May and November 2006 resulted in the detection of a transit occurring every 1.3 days. Follow-up radial velocity observations using the Swiss 1.2-metre Leonhard Euler Telescope confirmed that the transiting object was a planet.
Characteristics.
The equilibrium planetary temperature would be 1650 K, but measured temperature is higher at 1900 K. Dayside temperature measured in 2020 is 1957 K.
The study in 2012, utilizing a Rossiter–McLaughlin effect, have determined the planetary orbit is probably aligned with the equatorial plane of the star, misalignment equal to -1°.


Division for Planetary Sciences

The Division for Planetary Sciences (DPS) is a division within the American Astronomical Society (AAS) devoted to solar system research.
 It was founded in 1968. The first organizing committee members were: Edward Anders, Lewis Branscomb, Joseph W. Chamberlain, Richard M. Goody, John S. Hall, Arvidas Kliore, Michael B. McElroy, Tobias Owen, Gordon Pettengill, Carl Sagan, and Harlan James Smith. As of 2009, it is the largest special-interest division within the AAS. As of Oct 2010, membership totaled approximately 1415 planetary scientists and astronomers, including about 20% residing outside the U.S.
DPS sponsors five prizes. The Kuiper Prize honors outstanding contributions to the field of planetary science. The Urey Prize recognizes outstanding achievement in planetary research by a young scientist. The Masursky Award acknowledges outstanding service to planetary science and exploration. The Carl Sagan Medal recognizes and honors outstanding communication by an active planetary scientist to the general public. The Jonathan Eberhart Planetary Sciences Journalism Award is a prize that recognizes and stimulates distinguished popular writing on planetary sciences. The Claudia J. Alexander Prize recognizes outstanding achievement in planetary research by a mid-career scientist.
DPS has held meetings annually since 1970.
The official journal of the DPS is "Icarus".


John E. Baldwin

John Evan Baldwin FRS ( – ) was a British Astronomer who worked at the Cavendish Astrophysics Group (formerly Mullard Radio Astronomy Observatory) from 1954. He played a role in the development of interferometry in Radio Astronomy, and later astronomical optical interferometry and lucky imaging. He made the first maps of the radio emission from the Andromeda Galaxy and the Perseus Cluster, and measured the properties of many active galaxies. In 1985 he performed the first Aperture Masking Interferometry observations, and then led the construction and operation of the Cambridge Optical Aperture Synthesis Telescope, and helped develop the lucky imaging method. In 2001 he was awarded the Jackson-Gwilt Medal for his technical contributions to the fields of interferometry and aperture synthesis.
He matriculated as a member of Queens' College, Cambridge in 1949 and was a Life Fellow of the College from 1999 to his death in 2010.