An optical illusion is an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality. Illusions come in a wide variety. According to that, there are three main classes: physical and cognitive illusions, in each class there are four kinds: Ambiguities, distortions and fictions. A classical example for a physical distortion would be the apparent bending of a stick half immerged in water. An example for a physiological fiction is an afterimage. Three typical cognitive distortions are the Ponzo, Müller-Lyer illusion. Physical illusions are caused by e.g. by the optical properties of water. Physiological illusions arise in the eye or the visual pathway, e.g. from the effects of excessive stimulation of a specific receptor type. Cognitive visual illusions are the result of unconscious inferences and are those most known. Pathological visual illusions arise from pathological changes in the physiological visual perception mechanisms causing the aforementioned types of illusions.

A familiar phenomenon and example for a physical visual illusion is when mountains appear to be much nearer in clear weather with low humidity than they are. This is; the classical example of a physical illusion is when a stick, half immersed in water appears bent. This phenomenon has been discussed by Ptolemy and was a prototypical example for an illusion. Physiological illusions, such as the afterimages following bright lights, or adapting stimuli of excessively longer alternating patterns, are presumed to be the effects on the eyes or brain of excessive stimulation or interaction with contextual or competing stimuli of a specific type—brightness, position, size, etc; the theory is that a stimulus follows its individual dedicated neural path in the early stages of visual processing and that intense or repetitive activity in that or interaction with active adjoining channels causes a physiological imbalance that alters perception. The Hermann grid illusion and Mach bands are two illusions that are explained using a biological approach.

Lateral inhibition, where in receptive fields of the retina receptor signals from light and dark areas compete with one another, has been used to explain why we see bands of increased brightness at the edge of a color difference when viewing Mach bands. Once a receptor is active, it inhibits adjacent receptors; this inhibition creates contrast. In the Hermann grid illusion, the gray spots that appear at the intersections at peripheral locations are explained to occur because of lateral inhibition by the surround in larger receptive fields. However, lateral inhibition as an explanation of the Hermann grid illusion has been disproved. More recent empirical approaches to optical illusions have had some success in explaining optical phenomena with which theories based on lateral inhibition have struggled. Cognitive illusions are assumed to arise by interaction with assumptions about the world, leading to "unconscious inferences", an idea first suggested in the 19th century by the German physicist and physician Hermann Helmholtz.

Cognitive illusions are divided into ambiguous illusions, distorting illusions, paradox illusions, or fiction illusions. Ambiguous illusions are pictures or objects that elicit a perceptual "switch" between the alternative interpretations; the Necker cube is a well-known example. Distorting or geometrical-optical illusions are characterized by distortions of size, position or curvature. A striking example is the Café wall illusion. Other examples are the famous Müller-Lyer illusion and Ponzo illusion. Paradox illusions are generated by objects that are paradoxical or impossible, such as the Penrose triangle or impossible staircase seen, for example, in M. C. Escher's Descending and Waterfall; the triangle is an illusion dependent on a cognitive misunderstanding. Fictions are when a figure is perceived though it is not in the stimulus. To make sense of the world it is necessary to organize incoming sensations into information, meaningful. Gestalt psychologists believe one way this is done is by perceiving individual sensory stimuli as a meaningful whole.

Gestalt organization can be used to explain many illusions including the rabbit–duck illusion where the image as a whole switches back and forth from being a duck being a rabbit and why in the figure–ground illusion the figure and ground are reversible. In addition, Gestalt theory can be used to explain the illusory contours in the Kanizsa's Triangle. A floating white triangle, which does not exist, is seen; the brain has a need to see familiar simple objects and has a tendency to create a "whole" image from individual elements. Gestalt means "form" or "shape" in German. However, another explanation of the Kanizsa's Triangle is based in evolutionary psychology and the fact that in order to survive it was important to see form and edges; the use of perceptual organization to create meaning out of stimuli is the principle behind other well-known illusions includ

Callistopteris is a fern genus in the family Hymenophyllaceae. The genus is accepted in the Pteridophyte Phylogeny Group classification of 2016 but not by some other sources, which sink it into a broadly defined Trichomanes; the genus Callistopteris was erected by Edwin Copeland in 1938. Its status, like other genera in the family Hymenophyllaceae, remains disputed; the Pteridophyte Phylogeny Group classification of 2016 accepts the genus, placing it in the subfamily Trichomanoideae, saying that there are five species. As of October 2019, the Checklist of Ferns and Lycophytes of the World lists six species, whereas Plants of the World Online sinks the genus into Trichomanes; as of October 2019, the Checklist of Ferns and Lycophytes of the World accepted the following species: Callistopteris apiifolia Copel. Callistopteris baldwinii Copel. Callistopteris baueriana Copel. Callistopteris calyculata Copel. Callistopteris polyantha Copel. Callistopteris superba Ebihara & K. Iwats. List of fern families

William Joseph Kennedy is an American writer and journalist who won the 1984 Pulitzer Prize for his novel Ironweed. Many of his novels feature the interactions of members of the fictional Irish-American Phelan family in Albany, New York; the novels make use of incidents from the city's history as well as the supernatural. Kennedy's works include The Ink Truck, Billy Phelan's Greatest Game, Ironweed and Changó's Beads and Two-Tone Shoes. One reviewer said of Changó's Beads and Two-Tone Shoes that it was "written with such brio and encompassing humanity that it may well deserve to be called the best of the bunch". Kennedy published a nonfiction book entitled O Albany!: Improbable City of Political Wizards, Fearless Ethnics, Spectacular Aristocrats, Splendid Nobodies, Underrated Scoundrels. Kennedy was raised in Albany, New York, the son of William J. Kennedy and Mary E. McDonald. Kennedy was raised a Catholic, grew up in the North Albany neighborhood, he attended Christian Brothers Academy. Kennedy studied at Siena College in Loudonville, New York, from which he graduated in 1949.

Kennedy began pursuing a career in journalism after college by joining the Post Star in as a sports reporter. He was served in the US Army, where he worked for an Army newspaper in Europe. After his discharge, Kennedy joined the Albany Times Union as a reporter, he relocated to Puerto Rico in 1956 and became managing editor of the San Juan Star, a new English language newspaper. While living in San Juan, he befriended the journalist and author Hunter S. Thompson, a friendship that continued throughout their careers. While in Puerto Rico Kennedy met his mentor, Saul Bellow, who encouraged him to write novels. Kennedy, eager to leave Albany, returned to his hometown and worked for the Albany newspaper the Times Union as an investigative journalist, writing stories exposing activities of Daniel P. O'Connell and his political cronies of the dominant Democratic Party, his use of Albany as the setting for eight of his novels was described in 2011 by book critic Jonathan Yardley as painting "a portrait of a single city unique in American fiction".

Kennedy has received numerous honorary degrees, was presented with the inaugural SUNY Medallion of Distinction in May 2012 by the Chancellor of the State University of New York, so joined the ranks of the SUNY Distinguished Academy as a board-appointed Distinguished Professor. Kennedy lectured in creative writing and journalism from 1974 to 1982 at the University at Albany, becoming a full professor in 1983, he taught writing as a visiting professor at Cornell University during the 1982–1983 academic year. Kennedy received the 1984 Pulitzer Prize for Fiction for his novel Ironweed, he won the National Book Critics Circle Award. In 2001, he received the Peggy V. Helmerich Distinguished Author Award from the Tulsa Library Trust. William Kennedy received the Fitzgerald Award for Achievement in American Literature award in 2007, given annually in Rockville, Maryland where F. Scott Fitzgerald, his wife, his daughter are buried. In Puerto Rico, Kennedy married Daisy Sosa, they have three children. Kennedy resides in New York, a hamlet about 16 miles east of Albany.

The Ink Truck. New York: Viking Press, 1969. Legs. New York: Coward, McCann & Geoghegan, 1975. Billy Phelan's Greatest Game. New York: Viking Press, 1978. Ironweed. New York: Viking Press, 1983. Quinn's Book. New York: Viking Press, 1988. Old Bones. New York: Viking Press, 1992; the Flaming Corsage. New York: Viking Press, 1996. Roscoe. New York: Viking Press, 2002. Changó's Two-Tone Shoes. New York: Viking Adult, 2012. O Albany!: Improbable City of Political Wizards, Fearless Ethnics, Spectacular Aristocrats, Splendid Nobodies, Underrated Scoundrels. New York: Viking Press, 1983; the Making of Ironweed. New York: Viking Penguin, 1988. Riding the Yellow Trolley Car. New York: Viking Press, 1993; the Cotton Club. Co-authored with Francis Ford Coppola. New York: St. Martin's Press, 1986. Ironweed. Tri-Star, 1987. Grand View. Premiered at Capital Repertory Theatre, New York, 1996. In the System. HumaniTech* Short Play Project Premiere, University at Albany, March 2003. Charlie Malarkey and the Belly Button Machine. New York: Atlantic Monthly Press, 1986.

Charlie Malarkey and the Singing Moose. New York: Viking Children's Books, 1994. Flanagan, Thomas. O Albany!. New York Review of Books. April 25, 2002 Giamo, Benedict F; the Homeless of Ironweed: Blossoms on the Crag. Iowa City: University of Iowa Press, 1997. Gillespie, Michael Patrick. Reading William Kennedy. Syracuse: Syracuse University Press. Lynch, Vivian Valvano. Portraits of Artists: Warriors in the Novels of William Kennedy. Bethesda: International Scholars Publications, 1999. Mallon, Thomas. William Kennedy's Greatest Game; the Atlantic Monthly. February 2002. Seshachari, Neila C. Courtesans, Wives, & Vixens: The Many Faces of Female Power in Kennedy's Novels, AWP Conference, Albany, NY. April 17, 1999. Marowski, Daniel G. and Matur, editors. "William Kennedy." Contemporary Literary Criticism, Vol. 53, Detroit: Gale Research, 1989, pp. 189–201. Michener, Christian. From Then into Now: William Kennedy's Albany Novels. University of Scranton Press, 1998. Reilly, Edward C. Twayne's United States Authors Series: William Kennedy.

Boston: Twayne Publishers, 1991. Van Dover, J. K. Understanding William Kennedy. Columbia, SC: University of South Carolina Press, 1991. Seshachari, Neila C. editor. Conversations with William Kennedy. Jackson, MS: University Press of Mississippi, 1997. University at Albany – Famous Faculty

Thomas Joseph Thorp was an American football player and coach, sports writer, football and horse racing official. He served as the head football at Fordham University from 1912 to 1913 and at New York University from 1922 to 1924, compiling a career college football record of 21–17–4, he was born on March 6, 1884 in Manhattan, New York City in the neighborhood known as the Roaring Forties. He enrolled at Columbia University where he played at the tackle position for the school's football teams in 1903 and 1904, he was among the first non-Ivy League players to be named to Walter Camp's All-America team, was selected as an All-American in both 1903 and 1904. In October 1905, amid the movement to eradicate professionalism from college football, Columbia's faculty dropped Thorp from the university; the New York Times wrote that Thorp had been "the backbone" of the team and reported that Thorp's expulsion was "the worst blow that Columbia football has received" and a move that "cast the gloom of despair" over the prospects for the Columbia football team in 1905.

Upon being expelled from Columbia, Thorp sought admission to Cornell, but he was not able to acquire advance standing. Thorp played football. In the late 1900s, Thorp was hired as a sports writer for the New York Journal, he worked for a time for the New York American and the New York World. He continued to work as a journalist until 1936, when he became employed as a full-time official at horse racing tracks. Following his death in 1942, he was remembered as "a bona fide newspaperman, to say... he was an able, news-chasing, news-writing reporter." Thorp was head football coach at Fordham University for the 1912 and 1913 seasons, compiling a record of 7–7–2. Thorp was the 18th head football coach a New York University, serving for three seasons, from 1922 to 1924, compiling a record of 14–10–2; this ranks him third at NYU in winning percentage. When he was not coaching, Thorp worked as an official for college football games, he officiated at many of the significant eastern games and was the first easterner to be invited to officiate at a Rose Bowl Game.

He continued officiating at football games until 1940. In his years, Thorp lived in Rockville Centre, New York; when pari-mutuel was permitted in New England in 1933, Thorp became employed in the horse racing business. He served as the presiding steward at several race tracks, including Suffolk Downs, the Pagodas at Rockingham Park, Narragansett Park, Tropical Park in Florida, he was the general manager at the Empire City track in Yonkers, New York for a time. When Seabiscuit was matched against War Admiral, Thorp was the presiding steward at the race; when post time passed for the race, a crowd of reporters gathered, it was Thorp who delivered the news that "Seabiscuit scratched."In late June 1942, after presiding over the races at Suffolk Downs, Thorp suffered a heart attack at a Boston hotel. Thorp was survived by his mother and two brothers. Tom Thorp at Find a Grave

Pavan R is an Indian film editor, who has worked on Telugu and Kannada language films. Prawin Pudi joined the Telugu film industry as an assistant to editor Kotagiri Venkateswara Rao in 2000, before apprenticing under Sreekar Prasad and Marthand K. Venkatesh, he worked on Telugu films in the early 2000s as an assistant editor, before moving on to work as a free lancer for corporate films and television advertisements, before shifting to Pawan Kalyan Creative Works as an associate editor. After making his debut as an independent editor with Aakasa Ramanna, his first breakthrough came after working with Trivikram Srinivas in the action comedy Julai. Since Prawin has collaborated with the film maker in Attarintiki Daredi and S/O Satyamurthy, he has worked with Vikram Kumar, working with him in the successful Manam and the Tamil film, 24. He was associated in the making of I Am That Change, a short film produced by Allu Arjun to mark the 68th Independence Day of India. Prawin Pudi on IMDb

The 71st Infantry Division Kleeblatt was an infantry division of the German Army, raised in August 1939, shortly before the outbreak of World War II. It served garrison duty on the West Wall until May 1940, joined in the invasion of France; the division had captured Fort Douaumont in the Western Campaign. Thereafter it served in the occupations of Luxembourg until September. From October 1940 through January 1941 the division served as a demonstration unit for Oberkommando der Wehrmacht, it transferred to Przemyśl, joined Operation Barbarossa, the German invasion of the Soviet Union, in June 1941. In the fall it withdrew to Belgium for rest, once more served as a demonstration unit from November 1941 through to April 1942. Thereafter it was committed back to the Eastern Front, where it served under the German 6th Army and was lost during the Battle of Stalingrad in early 1943; the division was reconstituted over the summer and served on the Italian Front from the fall of 1943 through the end of 1944 ground to destruction at the Battle of Monte Cassino.

The remnants spent time in northern Italy where they opposed the 1st Canadian Infantry Division north of the Metauro River and on the Gothic Line with heavy losses. Following this, 71st Division fought in Hungary surrendering to the British near St. Veith in Austria; the division has been implicated in Tićan massacre, on 11 September 1943, when 84 civilians were executed. Structure of the division: Headquarters 191st Infantry Regiment 194th Infantry Regiment 211th Infantry Regiment 171st Artillery Regiment 171st Reconnaissance Battalion 171st Anti-Tank Battalion 171st Engineer Battalion 171st Signal Battalion 171st Divisional Supply Group The following officers commanded the 71st Infantry Division: Generalmajor Wolfgang Ziegler General der Infanterie Karl Weisenberger General der Infanterie Friedrich Herrlein General der Infanterie Alexander von Hartmann Generalmajor Fritz Roske Generalleutnant Wilhelm Raapke Generalmajor Eberhard von Schuckmann