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Mark Denny
Mark W. Denny (born 1951) is a professor of biology at Stanford University. His research on the intertidal zone of wave-swept shores has led to increased understanding of this habitat. His most publicized research is his work on locomotion of water striders, which led to the coining of the term "Denny's paradox" to explain a discrepancy between physics and previous understanding of how surface-dwelling animals such as these insects move. In 2008 he examined greyhounds, thoroughbred horses and human athletes trying to find their maximum running speed. He predicted the fastest possible time for men's 100 metres The 100 metres, or 100-meter dash, is a sprint race in track and field competitions. The shortest common outdoor running distance, the dash is one of the most popular and prestigious events in the sport of athletics. It has been contest ... will be 9.48 seconds. Books Denny is the author of several books, including: *''Biology and the Mechanics of Wave-Swept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford University
Stanford University, officially Leland Stanford Junior University, is a Private university, private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is considered among the most prestigious universities in the world. Stanford was founded in 1885 by Leland Stanford, Leland and Jane Stanford in memory of their only child, Leland Stanford Jr., who had died of typhoid fever at age 15 the previous year. Leland Stanford was a List of United States senators from California, U.S. senator and former List of governors of California, governor of California who made his fortune as a Big Four (Central Pacific Railroad), railroad tycoon. The school admitted its first students on October 1, 1891, as a Mixed-sex education, coeducational and non-denominational institution. Stanford University struggled financially after the death of Leland Stanford in 1893 and again after much of the campus was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertidal Zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species of life, such as seastars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the '' littoral zone'' or '' seashore'', although those can be defined as a wider region. The well-known area also includes steep rocky cliffs, sandy beaches, bogs or wetlands (e.g., vast mudflats). The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. The peritidal zone is similar but somewhat wider, extending from above the highest tide level to below the lowest. Organisms in the intertidal zone are adapted to an environment of harsh extremes, living in w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Striders
The Gerridae are a family of insects in the order Hemiptera, commonly known as water striders, water skeeters, water scooters, water bugs, pond skaters, water skippers, or water skimmers. Consistent with the classification of the Gerridae as true bugs (i.e., suborder Heteroptera), gerrids have mouthparts evolved for piercing and sucking, and distinguish themselves by having the unusual ability to walk on water, making them pleuston (surface-living) animals. They are anatomically built to transfer their weight to be able to run on top of the water's surface. As a result, one could likely find water striders present in any pond, river, or lake. Over 1,700 species of gerrids have been described, 10% of them being marine. While 90% of the Gerridae are freshwater bugs, the oceanic '' Halobates'' makes the family quite exceptional among insects. The genus ''Halobates'' was first heavily studied between 1822 and 1883 when Buchanan-White collected several different species during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denny's Paradox
In biology, Denny's paradox refers to the apparent impossibility of surface-dwelling animals such as the water strider generating enough propulsive force to move. It is named after biologist Mark Denny, and relates to animal locomotion on the surface layer of water. If capillary waves are assumed to generate the momentum transfer to the water, the animal's legs must move faster than the phase speed c_m of the waves, given by :c_m=\left(\frac\right)^, where g is the acceleration due to gravity, \sigma is the strength of surface tension, and \rho the density of water. For standard conditions, this works out to be about 0.23 m/s. In fact, water striders' legs move at speeds much less than this and, according to this physical picture, cannot move. Writing in the Journal of Fluid Mechanics, David Hu and John Bush state that Denny's paradox "rested on two flawed assumptions. First, water striders' motion was assumed to rely on the generation of capillary waves, since the pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greyhound
The English Greyhound, or simply the Greyhound, is a breed of dog, a sighthound which has been bred for coursing, greyhound racing and hunting. Since the rise in large-scale adoption of retired racing Greyhounds, the breed has seen a resurgence in popularity as a family pet. Greyhounds are defined as a tall, muscular, smooth-coated, "S-shaped" type of sighthound with a long tail and tough feet. Greyhounds are a separate breed from other related sighthounds, such as the Italian greyhound. The Greyhound is a gentle and intelligent breed whose combination of long, powerful legs, deep chest, flexible spine, and slim build allows it to reach average race speeds exceeding . The Greyhound can reach a full speed of within , or six strides from the boxes, traveling at almost for the first of a race. Appearance Males are usually tall at the withers, and weigh on average . Females tend to be smaller, with shoulder heights ranging from and weights from , although weights c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, '' Eohippus'', into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE. Horses in the subspecies ''caballus'' are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior. Horses are adapted to run, allowing them to quickly escape predators ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Footspeed
200px, Sprinting is a sport that requires development of footspeed Footspeed, or sprint speed, is the maximum speed at which a human can run. It is affected by many factors, varies greatly throughout the population, and is important in athletics and many sports, such as association football, rugby football, American football, track and field, field hockey, baseball, and basketball. Factors in speed The key determinant of footspeed in sprinting is the predominance of one distinct type of muscle fibre over another, specifically the ratio of fast-twitch muscles to slow-twitch muscles in a sprinter's physical makeup. Though fast-twitch muscles produce no more energy than slow-twitch muscles when they contract, they do so more rapidly through a process of anaerobic metabolism, though at the cost of inferior efficiency over longer periods of firing.Quinn, Elizabeth"Fast and Slow Twitch Muscle Fibers" ''About.com'', retrieved November 26, 2007. The average human has an almost-equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
100 Metres
The 100 metres, or 100-meter dash, is a sprint race in track and field competitions. The shortest common outdoor running distance, the dash is one of the most popular and prestigious events in the sport of athletics. It has been contested at the Summer Olympics since 1896 for men and since 1928 for women. The inaugural World Championships were in 1983. The reigning 100 m Olympic or world champion is often named "the fastest man or woman in the world". Fred Kerley and Shelly-Ann Fraser-Pryce are the reigning world champions; Marcell Jacobs and Elaine Thompson-Herah are the men's and women's Olympic champions. On an outdoor 400-metre running track, the 100 m is held on the home straight, with the start usually being set on an extension to make it a straight-line race. There are three instructions given to the runners immediately before and at the beginning of the race: "on your marks," "set," and the firing of the starter's pistol. The runners move to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (a twentieth of a pound in pre-decimal UK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1951 Births
Events January * January 4 – Korean War: Third Battle of Seoul – Chinese and North Korean forces capture Seoul for the second time (having lost the Second Battle of Seoul in September 1950). * January 9 – The Government of the United Kingdom announces abandonment of the Tanganyika groundnut scheme for the cultivation of peanuts in the Tanganyika Territory, with the writing off of £36.5M debt. * January 15 – In a court in West Germany, Ilse Koch, The "Witch of Buchenwald", wife of the commandant of the Buchenwald concentration camp, is sentenced to life imprisonment. * January 20 – Winter of Terror: Avalanches in the Alps kill 240 and bury 45,000 for a time, in Switzerland, Austria and Italy. * January 21 – Mount Lamington in Papua New Guinea 1951 eruption of Mount Lamington, erupts catastrophically, killing nearly 3,000 people and causing great devastation in Oro Province. * January 25 – Dutch author Anne de Vries releases the first volume of his children's nove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Related categories * :Year of birth missing (living people) / :Year of birth unknown * :Date of birth missing (living people) / :Date of birth unknown * :Place of birth missing (living people) / :Place of birth unknown * :Year of death missing / :Year of death unknown * :Date of death missing / :Date of death unknown * :Place of death missing / :Place of death unknown * :Missing middle or first names See also * :Dead people * :Template:L, which generates this category or death years, and birth year and sort keys. : {{DEFAULTSORT:Living people 21st-century people People by status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century American Biologists
The 1st century was the century spanning AD 1 (Roman numerals, I) through AD 100 (Roman numerals, C) according to the Julian calendar. It is often written as the or to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or History by period, historical period. The 1st century also saw the Christianity in the 1st century, appearance of Christianity. During this period, Europe, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius (AD 43). The reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. Later in the century the Julio-Claudian dynasty, which had been founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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