Friedrich Bessel

Friedrich Wilhelm Bessel was a German astronomer, mathematician and geodesist. He was the first astronomer who determined reliable values for the distance from the sun to another star by the method of parallax. A special type of mathematical functions were named Bessel functions after Bessel's death, though they had been discovered by Daniel Bernoulli and generalised by Bessel. Bessel was born in Minden, administrative center of Minden-Ravensberg, as second son of a civil servant, he was born into a large family in Germany. At the age of 14 Bessel was apprenticed to the import-export concern Kulenkamp at Bremen; the business's reliance on cargo ships led him to turn his mathematical skills to problems in navigation. This in turn led to an interest in astronomy as a way of determining longitude. Bessel came to the attention of a major figure of German astronomy at the time, Heinrich Wilhelm Olbers, by producing a refinement on the orbital calculations for Halley's Comet in 1804, using old observation data taken from Thomas Harriot and Nathaniel Torporley in 1607.

Two years Bessel left Kulenkamp and became Johann Hieronymus Schröter's assistant at Lilienthal Observatory near Bremen. There he worked on James Bradley's stellar observations to produce precise positions for some 3,222 stars. In January 1810, at the age of 25, Bessel was appointed director of the newly founded Königsberg Observatory by King Frederick William III of Prussia. On the recommendation of fellow mathematician and physicist Carl Friedrich Gauss he was awarded an honorary doctor degree from the University of Göttingen in March 1811. Around that time, the two men engaged in an epistolary correspondence. However, when they met in person in 1825, they quarrelled. In 1842 Bessel took part in the annual meeting of the British Association for the Advancement of Science in Manchester, accompanied by the geophysicist Georg Adolf Erman and the mathematician Carl Gustav Jacob Jacobi. Bessel married Johanna, the daughter of the chemist and pharmacist Karl Gottfried Hagen, the uncle of the physician and biologist Hermann August Hagen and the hydraulic engineer Gotthilf Hagen, the latter Bessel's student and assistant from 1816 to 1818.

The physicist Franz Ernst Neumann, Bessel's close companion and colleague, was married to Johanna Hagen's sister Florentine. Neumann introduced Bessel's exacting methods of measurement and data reduction into his mathematico-physical seminar, which he co-directed with Carl Gustav Jacob Jacobi at Königsberg; these exacting methods had a lasting impact upon the work of Neumann's students and upon the Prussian conception of precision in measurement. Bessel had three daughters, his eldest daughter, married Georg Adolf Erman, member of the scholar family Erman. One of their sons was the renowned Egyptologist Adolf Erman. After several months of illness Bessel died in March 1846 at his observatory from retroperitoneal fibrosis. While the observatory was still in construction Bessel elaborated the Fundamenta Astronomiae based on Bradley's observations; as a preliminary result he produced tables of atmospheric refraction that won him the Lalande Prize from the French Academy of Sciences in 1811. The Königsberg Observatory began operation in 1813.

Starting in 1819, Bessel determined the position of over 50,000 stars using a meridian circle from Reichenbach, assisted by some of his qualified students. The most prominent of them was Friedrich Wilhelm Argelander. With this work done, Bessel was able to achieve the feat for which he is best remembered today: he is credited with being the first to use the stellar parallax in calculating the distance to a star. Astronomers had believed for some time that parallax would provide the first accurate measurement of interstellar distances. In 1838 Bessel announced. Given the current measurement of 11.4 ly, Bessel's figure had an error of 9.6%. Nearly at the same time Friedrich Georg Wilhelm Struve and Thomas Henderson measured the parallaxes of Vega and Alpha Centauri; as well as helping determine the parallax of 61 Cygni, Bessel's precise measurements using a new meridian circle from Adolf Repsold allowed him to notice deviations in the motions of Sirius and Procyon, which he deduced must be caused by the gravitational attraction of unseen companions.

His announcement of Sirius's "dark companion" in 1844 was the first correct claim of a unobserved companion by positional measurement, led to the discovery of Sirius B. Bessel was the first scientist who realized the effect called personal equation, that several observing persons determine different values recording the transition time of stars. In 1824, Bessel developed a new method for calculation the circumstances of eclipses using the so-called Besselian elements, his method simplified the calculation to such an extent, without sacrificing accuracy, that it is still in use today. Bessel's work in 1840 contributed to the discovery of Neptune in 1846 at Berlin Observatory, several months after Bessel's death. On Bessel's proposal the Prussian Academy of Sciences started the edition of the Berliner Akademische Sternkarten as an international project. One unpublished new chart enabled Johann Gottfried Galle to find Neptune near the position calculated by LeVerrier in 1846. In the second decade of the 19th century while studying the dynamics of'many-body' gravitational systems, Bessel developed what are now known as Bessel functions.

Critical for the solution of certain differential equations, these

Emblem of Tamil Nadu

The Emblem of Tamil Nadu is the official state emblem of Tamil Nadu and is used as the official state symbol of the Government of Tamil Nadu. It consists of the Lion Capital of Ashoka without the bell lotus foundation and flanked on either side by an Indian flag. Behind the capital, is the image of a Gopuram or temple tower based on the West Tower of Srivilliputhur Andal Temple; the state emblem was designed in 1949 by artist R. Krishna Rao, a native of Madurai. Krishna Rao was honoured with titles for his contribution to the state. A student of the Government College of Fine Arts and Crafts in Chennai, who went on to become the principal of the college Rao was approached to design the emblem in 1948, when he was a professor of applied arts in the college. Around the rim of the seal runs an inscription in Tamil script, one at the top தமிழ் நாடு அரசு and other at the bottom வாய்மையே வெல்லும், it is the only state. Although the gopuram in the emblem is generic and does not carry specific references, Thiruvilliputhur Andal Temple gopuram came to be known as the state emblem in government records due to the TKC-Reddy episode.

But R Krishna Rao, the artist who created it said he had the Madurai Meenakshi temple's west'gopuram' in mind while designing a generic `gopuram' for the emblem. A monograph on Rao, published by the Lalit Kala Akademi quotes him as saying, "Hailing from Madurai, it was only proper that I should incorporate the Madurai temple in the state government's emblem." Rao's student G Chandrashekaran a former principal of the college, feels the theory of Madurai temple being the inspiration may not be off the mark. "It could be said that the inspiration for designing the emblem came from the Madurai temple, as Krishna Rao had done several watercolours of the structure. There are no records of him having painted the Thiruvilliputhur temple." K Kamala, Krishna Rao's daughter and an artist herself, says that her father regretted the gopuram being wrongly identified all the time. "He always asked me to tell people that it was the Madurai gopuram and not of Thiruvilliputhur", says Kamala, adding that she got to see the original painting at the Government College of Fine Arts and Crafts in Chennai in 2009.

"The features of the gopuram can be seen in the original painting, one could see well that it is the Madurai gopuram. My father had painted the figurines of Siva and Parvati on the Rishaba vahanam, seen in the gopuram in the Madurai temple; that was a clear sign," she says. Efforts to trace the original painting, supposed to have been incorporated into the state emblem were futile. Flag of Tamil Nadu Tamil Thai Valthu National Emblem of India List of Indian state emblems

T-Force (film)

T-Force is a 1994 science fiction film directed by Richard Pepin. Set in the near future, its plot concerns a group of law enforcement cyborgs, called "cybernauts" which, after being threatened with their shutdown, rebel against their superiors and the authorities. A terrorist group seizes the British embassy in downtown Los Angeles. All seems lost, but "T-Force," the world's first cybernetic law enforcement team is deployed and within minutes, more than thirty terrorists are dead. However, one of the members of T-Force, goes too far and shoots a disarmed and surrendering female terrorist, he destroys a terrorist helicopter with six hostages on board with a grenade launcher. The mayor and the Chief of the LAPD decide to shut down the program and disassemble the cybernauts despite protest from the cybernaut's chief scientist. Perceiving their shutdown a threat to their self-preservation, the cyborgs rebel and go on a killing rampage by targeting the mayor and the chief. Lieutenant Jack Floyd of the LAPD teams up with Cain, one of the cybernauts who chose to obey the law, to hunt down the renegade cybernauts and destroy them.

T-Force on IMDb T-Force trailer on YouTube