In biology, what 3-letter word derived from the Swedish for 'play' is a gathering of males of certain bird species for the purposes of mating display?

Evolution: Glossary A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | Y | Z acquired trait: A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation (for example, the large muscles of a weightlifter). adaptation: Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment. Also used to describe the process of genetic change within a population, as influenced by natural selection . adaptive landscape: A graph of the average fitness of a population in relation to the frequencies of genotypes in it. Peaks on the landscape correspond to genotypic frequencies at which the average fitness is high, valleys to genotypic frequencies at which the average fitness is low. Also called a fitness surface. adaptive logic: A behavior has adaptive logic if it tends to increase the number of offspring that an individual contributes to the next and following generations. If such a behavior is even partly genetically determined, it will tend to become widespread in the population. Then, even if circumstances change such that it no longer provides any survival or reproductive advantage, the behavior will still tend to be exhibited -- unless it becomes positively disadvantageous in the new environment. adaptive radiation: The diversification, over evolutionary time, of a species or group of species into several different species or subspecies that are typically adapted to different ecological niches (for example, Darwin's finches). The term can also be applied to larger groups of organisms, as in "the adaptive radiation of mammals ." adaptive strategies: A mode of coping with competition or environmental conditions on an evolutionary time scale. Species adapt when succeeding generations emphasize beneficial characteristics. agnostic: A person who believes that the existence of a god or creator and the nature of the universe is unknowable. algae: An umbrella term for various simple organisms that contain chlorophyll (and can therefore carry out photosynthesis ) and live in aquatic habitats and in moist situations on land. The term has no direct taxonomic significance. Algae range from macroscopic seaweeds such as giant kelp, which frequently exceeds 30 m in length, to microscopic filamentous and single-celled forms such as Spirogyra and Chlorella. allele: One of the alternative forms of a gene. For example, if a gene determines the seed color of peas, one allele of that gene may produce green seeds and another allele produce yellow seeds. In a diploid cell there are usually two alleles of any one gene (one from each parent). Within a population there may be many different alleles of a gene; each has a unique nucleotide sequence. allometry: The relation between the size of an organism and the size of any of its parts. For example, an allometric relation exists between brain size and body size, such that (in this case) animals with bigger bodies tend to have bigger brains. Allometric relations can be studied during the growth of a single organism, between different organisms within a species, or between organisms in different species. allopatric speciation: Speciation that occurs when two or more populations of a species are geographically isolated from one another sufficiently that they do not interbreed. allopatry: Living in separate places. Compare with sympatry . amino acid: The unit molecular building block of proteins , which are chains of amino acids in a certain sequence. There are 20 main amino acids in the proteins of living things, and the properties of a protein are determined by its particular amino acid sequence. amino acid sequence: A series of amino acids, the building blocks of proteins , usually coded for by DNA . Exceptions are those coded for by the RNA of certain viruses, such as HIV. ammonoid: Extinct relatives of cephalopods (squid, octopi, and chambered nautiluses), these mollusks had coiled shells and are found in the fossil reco


Global warming be damned. The 19th century biologist Louis Agassiz who studied Alpine glaciers was the first to propose that the Earth had been subject what phenomena in the past?

Global Warming and the Age of the Earth: a Lesson on the Nature of Scientific Knowledge | Watts Up With That? Watts Up With That? The world's most viewed site on global warming and climate change Menu In the wake of Karl et al. 2015, which revises data to match a consensus, we can all take a lesson from how scientific consensus has operated in the past Guest essay by Dr. David Deming The world stands on the verge of committing itself to limits on the emission of carbon dioxide that would drastically reduce the use of fossil fuels. If this fateful decision is made, the economies of developed nations will be strangled. Human prosperity will be reduced. Our ability to solve pressing problems, both human and environmental, will be severely limited. We have been told that these shackles must be imposed to forestall a hypothetical global warming projected to occur some time in the distant future. But to date the only unambiguous evidence for planetary warming is a modest rise in temperature (less than one degree Celsius) that falls well within the range of natural variation. The validity of warming predictions depends upon the questionable reliability of computer models of the climate system. But Earth’s climate system is complex and poorly understood. And the integrity of the computer models cannot be demonstrated or even tested. To anyone with an awareness of the nature and limitations of scientific knowledge, it must appear that the human race is repeating a foolish mistake from the past. We have been down this road before, most notably in the latter half of the nineteenth century when it appeared that mathematics and physics had conclusively answered the question of the Earth’s age. At that time, a science that had been definitely “settled” fell apart in the space of a few years. The mathematical models that appeared to be so certain proved to be completely, even ridiculously wrong. The age of the Earth is one of the great questions that has puzzled people for thousands of years. In Meteorologica, Aristotle (384-322 BC) asserted that the world was eternal. But with the advent of Christianity and Islam, scholars began to assume that humanity was coeval with the Creation of the world. It followed that the age of the Earth could be estimated from a careful examination of sacred writings. The first person to make a quantitative estimate of the Earth’s age was the Islamic scientist al-Biruni (c. 973-1050). al-Biruni based his chronology on the Hindu, Jewish, and Christian religious scriptures. He divided the history of the world into eras, and concluded that it had been less than ten thousand years since the Creation. Working in the tradition begun by al-Biruni, Bishop James Ussher (1581-1686) estimated the age of the Earth by meticulously studying the Bible and other historical documents. In The Annals of the World Deduced from the Origin of Time, Ussher pinpointed the date of Creation as the “night preceding the 23rd of October, 4004 BC.” Ussher’s scholarship was impressive, and his dates were accepted as the standard chronology. Bible editors began to place Ussher’s dates in the margins of their texts. Isaac Newton (1642-1727), the greatest scientist of the age, was also a Biblical fundamentalist who believed in a young Earth. Newton explained to his nephew, John Conduitt, that the Earth could not be old because all human technology was of recent invention. Like Ussher, Newton wrote his own universal history, Chronology of Ancient Kingdoms Amended, that was published posthumously in 1728. The procedures for establishing a scientific estimate of the age of the Earth were laid out in the seventeenth century by the Danish anatomist, Nicolaus Steno (1638-1686). Steno was the first person to state unequivocally that the history of the Earth was not to be found in human chronicles, but in the Earth itself. Steno’s principles of geologic investigation became the basis for establishing the relative age of rock sequences and the foundation of historical geology. Armed with Steno’s principles, eighteenth century naturalists began to s


If Jane Goodall is to chimpanzees, Birutė Galdikas, who worked for a long time in Borneo is to what animal?

Dr. Biruté Mary Galdikas Bio | Orangutan Foundation International | Orangutan Foundation International Dr. Galdikas' Biography Search for: Scientist, conservationist, educator: for over four decades Dr. Biruté Mary Galdikas has studied and worked closely with the orangutans of Indonesian Borneo in their natural habitat, and is today the world’s foremost authority on the orangutan. [Update: Dr. Galdikas has a twitter account here. ] Galdikas was born after the end of World War II, while her parents were en route to Canada from their homeland of Lithuania. Galdikas grew up and went to school in Toronto. After checking out her first library book, Curious George, at the age of six, Galdikas was inspired by the man in the yellow hat and his unruly monkey. By the second grade, she had decided on her life’s work: she wanted to be an explorer. When her family moved from Canada to the United States in 1964, Galdikas had completed a year of studies at the University of British Columbia (UBC) in Vancouver. She continued her studies of natural sciences at the University of California at Los Angeles (UCLA), quickly earning her bachelor’s degree in psychology and zoology in 1966 and her master’s degree in anthropology in 1969. It was there as a graduate student that she first met Kenyan anthropologist Dr. Louis Leakey and spoke with him about her desire to study orangutans. Although Dr. Leakey seemed disinterested at first, Galdikas persuaded him of her passion. After three years, Dr. Leakey finally found the funding for Galdikas’ orangutan studies, as he had previously done with both Jane Goodall and Dian Fossey for their respective studies on chimpanzees and mountain gorillas. In 1971, Galdikas and her then husband, Rod Brindamour, arrived in one of the world’s last wild places, Tanjung Puting Reserve in Indonesian Borneo. There were no telephones, roads, electricity, television, or regular mail service at that time. Before she left the U.S., she was told by her professors and others that it “couldn’t be done”; she wouldn’t be able to study orangutans in the wild. They were too elusive and wary, living almost entirely in deep swamps. Before long, however, her hard work and determination had paid off. She set up “Camp Leakey,” named after her mentor and began documenting the ecology and behavior of the wild orangutans. Four years later, she wrote the cover article for National Geographic Magazine, bringing orangutans widespread international public attention for the first time. The article was illustrated with Brindamour’s photographs. Although Dr. Leakey seemed disinterested at first, Galdikas persuaded him of her passion. After three years, Dr. Leakey finally found the funding for Galdikas’ orangutan studies. Dr. Galdikas has lectured extensively on the orangutans and their tropical rain forest habitat to thousands of people and numerous institutions in Indonesia and throughout the world. Her dedication not only to understand the nature of the orangutan but also to preserve the creature’s rapidly diminishing natural habitat extends to the people, culture, and environment as well. After 40 years in Tanjung Puting , now a national park, Galdikas has conducted the longest continuous study by one principal investigator of any wild mammal in the world. Galdikas was the first to document the long orangutan birth interval which averaged 7.7 years at Tanjung Puting. She recorded over 400 types of food consumed by orangutans, providing unprecedented detail about orangutan ecology. She also helped elucidate the nature of orangutan social organization and mating systems. To support her work at Camp Leakey and to help support orangutans around the world, Dr. Galdikas and her colleagues set up Orangutan Foundation International (OFI) in 1986 with its home base in Los Angeles, California. Dr. Galdikas and her husband, Borneo native Pak Bohap bin Jalan, were also instrumental in establishing sister organizations in Australia, Indonesia, and the United Kingdom. A Lithuanian bank, Ukio Bank, established the Biruté Galdikas Ecology and Support Fo


In biology, the theory that states that an animal's development from embryo to adult resembles the stages in the evolution of its ancestors is commonly expressed as what three word phrase?


The common basilisk is a lizard found in Central and South American rain-forests and is known for its ability to run on water. What is its appropriate nickname?

Basilisk Lizard - Basiliscus basiliscus - Details - Encyclopedia of Life 9 External links Taxonomy and etymology[ edit ] The common basilisk is named for the creature of Greek mythology made up of parts of a rooster , snake , and lion which could turn a man to stone by its gaze: the basilisk . [2] Its generic , specific and common names all derive from the Greek basilískos (βασιλίσκος) meaning "little king". The specific epithet was given in Carolus Linnaeus ' 10th edition of Systema Naturae . [2] When startled, the common basilisk escapes by speeding to the nearest edge of water—and continues sprinting. The lizard runs on only its hind legs in an erect position, holding its fore legs to its sides. This basilisk is so adroit on water because its feet are large and equipped with flaps of skin along the toes; when moving quickly, the lizard can cross a surface of water before sinking. On water, it runs an average speed of 8.4 km/h (or 5.2 mph), which is just a little slower than its speed on land. Younger basilisks can run 10 to 20 meters on water, while adults cross only a few meters before sinking. Adults do not move slowly, but they weigh more and cannot sprint for as long a time. Once a basilisk submerges, it continues swimming until it is sufficiently far from its pursuer—if the predator has followed past the bank. Although this lizard stays close to water to escape terrestrial predators, it swims only when necessary because some other aquatic animals would eat the basilisk given the chance. Range and habitat[ edit ] The common basilisk is found throughout Central America and in northwestern South America, usually living in low elevations, from sea level to 600 m. In Costa Rica , this basilisk can be found as high as 1,200 m in some places. The species ranges from southwestern Nicaragua to northwestern Colombia on the Pacific side, and from central Panama to northwestern Venezuela on the Atlantic side. In Costa Rica, it is mostly found on the Pacific side of the country. The equivalent species on the Atlantic side is the green basilisk, which occupies similar habitats and has similar biology. [2] It has been introduced to Florida as a feral species. [3] Description[ edit ] The common basilisk can be distinguished from similar species within its range by its large size and the high fin-like crests down its back. Most are brown and cream in colour. Males also have high crests on their heads and tails. Both sexes are brown to olive, and have a white, cream or yellow stripe on the upper lip and a second stripe along either side of their bodies; these stripes have higher contrast in juveniles and fade as the lizards age. Hatchlings weigh a mere 2 g and are 37 to 43 mm long. Adults can grow up to two and a half feet long. Females are generally 135 to 194 g, and weigh half as much as males. The tails of these lizards comprise 70 to 75% of their total length: for example, on an 800-mm-long (31.5-in-long) lizard, 600 mm of its length is tail. The common basilisk has a large mouth with saw-like teeth on the inner sides of the jaw. They have been known to run up to 7 mph (11 km/h). While the basilisk is most known for its ability to run on water, it is also an excellent climber and swimmer; the basilisk has been known to stay under water for up to half an hour. The average lifespan is seven years in captivity; in the wild, it tends to be less because of predators. Diet[ edit ] This basilisk is an omnivore ; its diet consists of insects , flowers, and small vertebrates such as snakes , birds , eggs , and fish . [2] Predators[ edit ] The common basilisk has many natural predators - large reptiles, birds, and some mammals. To avoid predators, it can conceal itself under leaves on the forest floor and can remain motionless for a long time. When the common basilisk must flee, though, its skill of running on water can help it avoid many predators. Reproduction[ edit ] Females lay three to four clutches of 10–20 eggs a year. [2] Eggs hatch after about three months and the young weigh about two grams and are up to three inches long. The


What is the only major planet of the Solar System that takes its English name from Greek mythology?

Planet Names and Greek Mythology Planet Names How do planets and their moons get ther names? With the exception of Earth, all of the planets in our solar system have names from Greek or Roman mythology. This tradition was continued when Uranus, Neptune, and Pluto were discovered in more modern times. Mercury (Hermes) is the god of commerce, travel and thievery in Roman mythology. The planet probably received this name because it moves so quickly across the sky. Venus (Aphrodite) is the Roman goddess of love and beauty. The planet is aptly named since it makes a beautiful sight in the sky, with only the Sun and the Moon being brighter. Earth (Gaia) is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic. There are, of course, many other names for our planet in other languages. Jupiter (Zeus) was the King of the Gods in Roman mythology, making the name a good choice for what is by far the largest planet in our solar system Mars (Ares) is the Roman god of War. The planet probably got this name due to its red color. Jupiter was the King of the Gods in Roman mythology, making the name a good choice for what is by far the largest planet in our solar system. Saturn (Cronus) is the Roman god of agriculture. Uranus is the ancient Roman deity of the Heavens, the earliest supreme god. Neptune (Poseidon), was the Roman god of the Sea. Given the beautiful blue color of this planet, the name is an excellent choice! Pluto (Hades) is the Roman god of the underworld in Roman mythology. Perhaps the planet received this name because it's so far from the Sun that it is in perpetual darkness. Natural Satellites For those moons have been known for a long time (such as the Galilean moons of Jupiter), the names were assigned from mythological characters. For example, the moons of Jupiter were named for characters who had roles in the life of Zeus (the Greek mythology counterpart of the Roman God Jupiter). For example: Metis (first wife of Zeus) Copyright 2005-16, Greek-Mythology-Gods.com


The mathematician Benoit Mandelbrot is best known for his work on the geometry of what unusual shapes?

IBM100 - Fractal Geometry IBM100 Choose your Country and Language:     Fractal geometry in They Were There Learn more about Benoit Mandelbrot and fractal geometry in the IBM Centennial film, They Were There. (Beginning at 26:55) The passing of a maverick On October 14, 2010, the scientific community lost a great colleague, visionary and friend as Benoit Mandelbrot passed away at the age of 85 in Cambridge, Massachusetts. Dr. Mandelbrot is survived by his wife Aliette; two sons, Laurent and Didier; and three grandchildren. Mandelbrot said “In the whole of science, the whole of mathematics, smoothness was everything. What I did was to open up roughness for investigation.” “While a maverick’s story is not in the least an example to follow, it may carry the following useful message: a good sprinkling of diversity is just as indispensable to the good functioning and survival of science as it is to the welfare of society as a whole.” “I overturned a horn of plenty in which all kinds of things humanity has always known were located.” “It may have become true that people who think best in shapes tend to go into the arts, and that people who go into science or mathematics are those who think in formulas. On these grounds, one might argue that I was misplaced in going into science, but I do not think so. Anyhow, I was lucky to be able—eventually—to devise a private way of combining mathematics, science, philosophy and the arts.” “Bottomless wonders spring from simple rules…repeated without end.”   Geometry. Its principles are taught to young students across the world. The Pythagorean theorem. Surface area and volume. Pi. This classical, or Euclidean, geometry is perfectly suited for the world that humans have created. But if one considers the structures that are present in nature, that which are beyond the realm of smooth human construction, many of these rules disappear. Clouds are not perfect spheres, mountains are not symmetric cones, and lightning does not travel in a straight line. Nature is rough, and until very recently this roughness was impossible to measure. The discovery of fractal geometry has made it possible to mathematically explore the kinds of rough irregularities that exist in nature. In 1961, Benoit Mandelbrot was working as a research scientist at the Thomas J. Watson Research Center in Yorktown Heights, NY. A bright young academic who had yet to find his professional niche, Mandelbrot was exactly the kind of intellectual maverick IBM had become known for recruiting. The task was simple enough: IBM was involved in transmitting computer data over phone lines, but a kind of white noise kept disturbing the flow of information—breaking the signal—and IBM looked to Mandelbrot to provide a new perspective on the problem. Since he was a boy, Mandelbrot had always thought visually, so instead of using the established analytical techniques, he instinctually looked at the white noise in terms of the shapes it generated—an early form of IBM’s now-renowned data visualization practices. A graph of the turbulence quickly revealed a peculiar characteristic. Regardless of the scale of the graph, whether it represented data over the course of one day or one hour or one second, the pattern of disturbance was surprisingly similar. There was a larger structure at work. The problem was familiar to Mandelbrot, and he recalled the advice his mathematician uncle, Szolem Mandelbrojt, had given him years ago in France—attempt to make something of the obscure theories of iteration established by French mathematicians Pierre Fatou and Gaston Julia. Their work intrigued mathematicians around the world and revolved around the simplest of equations: z = z² + c. With a variable of z and parameter of c, this equation maps values on the complex plane—where the x-axis measures the real part of complex number and the y-axis measures the imaginary part ( i) of a complex number. At the time of the advice, Mandelbrot couldn’t find any breakthrough, but the intellectual freedom he found at IBM allowed him to fully engage this new project. In 1980, bu


What controversial theory in evolutionary biology proposes that most sexually reproducing species will experience little or no evolutionary change and remain in an extended state called stasis?

21st Century British Nationalism: Oil and The Great Collapse Cognitive Dissidence, The mechanism of warfare and subversion for intellectual revolutionaries. Monday, 9 November 2009 Oil and The Great Collapse In recent years a challenge to classic Darwinian theory has come via the idea of Punctuated Equilibrium. Punctuated equilibrium is a theory in evolutionary biology which proposes that most sexually reproducing species will experience little evolutionary change for most of their geological history (in an extended state called stasis). When evolution occurs, it is localized in rare, rapid events of branching speciation (called cladogenesis). Cladogenesis is simply the process by which species split into two distinct species, rather than one species gradually transforming into another. Thus, "punctuated equilibria is a model for discontinuous tempos of change (in) the process of speciation and the deployment of species in geological time." Punctuated equilibrium is commonly contrasted against the theory of phyletic gradualism, which states that evolution generally occurs uniformly and by the steady and gradual transformation of whole lineages (anagenesis). In this view, evolution is seen as generally smooth and continuous. http://en.wikipedia.org/wiki/Punctuated_equilibrium This theory demolishes the idea of gradual evolution and instead proposes a theory based on sudden evolutionary spurts, when a species suddenly undergoes change into a new species and is then replaced by this whole new species. Incremental change leads to qualitative change, in a moment of accelerated Punctuated Equilibrium. The same thing occurs in politics. Continuing on from De Benoist and his Convergence of Catastrophies theory we see that a system, such as a political system, undergoes a negative feedback loop. A negative feedback loop is a feedback that reduces the output of a system. In other words a society is no longer undergoing progressive social evolution. More and more energy and money is being spent on sustaining the present social level than could be gained from social expansion. In other words, the system is now so dysfunctional that even if the system expanded to achieve its most efficient expansion capacity, that this rate of expansion would still not match the rate of internal social collapse. Eg the economy could at its very best only expand by 4 % per annum but the social costs of sustaining the present levels of social complexity are deficit debts of around 5 % per annum. In other words, all new growth goes on cutting old debts. Each year the system undergoes reversion, and cuts its levels of social progress eg more people lose their jobs, wages are cut, unemployment rises, benefit cuts are imposed etc etc. Society has entered a negative feedback loop. The ONLY way that societies save themselves from negative feedback loops is by injections of new energy. Human progress is not measured by the GDP but by GEP - the Gross Energy Product of a nation. Any nation that produces more energy by itself than it requires for its own internal needs, is an nation in an ‘ Energy Credit’ situation - and therefore it is a nation that is capable of social and economic progress. Any nation that produces less than it needs in energy terms is in Energy Deficit and is incapable of social and economic progress. For example, because of North Sea oil depletion in 2007 the UK is now a net importer of energy. As a result of that situation the British Army were sent to Iraq to secure Iraqi oil for the US and into Afghanistan to secure the oil and gas pipelines that feed the West its gas and oil. The decision by Winston Churchill as First Lord of The Admiralty in 1912 to switch from coal to oil fired engines for British battleships was the most important decision of the 20th century for Britain and the whole politics of the 20th century. Not only did this open up the Empire, as now Royal Navy ships could be used to protect shipping, it gave birth to the geo-politics of Oil Imperialism. Tanks, planes and lorries could be used to assert British control over


What substance registered in 1870 and widely used as a replacement for ivory is regarded as the first synthetic plastic?

What does celluloid mean? The genre of cinema; film. Origin: Former trademark of Celluloid Manufacturing Company Webster Dictionary(0.00 / 0 votes)Rate this definition: Celluloid(noun) a substance composed essentially of gun cotton and camphor, and when pure resembling ivory in texture and color, but variously colored to imitate coral, tortoise shell, amber, malachite, etc. It is used in the manufacture of jewelry and many small articles, as combs, brushes, collars, and cuffs; -- originally called xylonite Origin: [Cellulose + -oid.] Freebase(0.00 / 0 votes)Rate this definition: Celluloid Celluloids are a class of compounds created from nitrocellulose and camphor, with added dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862 and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is easily molded and shaped, and it was first widely used as an ivory replacement. Celluloid is highly flammable and also easily decomposes, and is no longer widely used. Its most common uses today are in table tennis balls and guitar picks. Numerology The numerical value of celluloid in Chaldean Numerology is: 8 Pythagorean Numerology


The Danjon Scale is a five-point scale for measuring the appearance and luminosity of a particular heavenly body during what type of event?

brightness scale - это... Что такое brightness scale? brightness scale brightness sensing device Смотреть что такое "brightness scale" в других словарях: Scale (social sciences) — In the social sciences, scaling is the process of measuring or ordering entities with respect to quantitative attributes or traits. For example, a scaling technique might involve estimating individuals levels of extraversion, or the perceived… …   Wikipedia Extragalactic distance scale — The extragalactic distance scale is a series of techniques used today by astronomers to determine the distance of cosmological bodies (beyond our own galaxy) not easily obtained with traditional methods. Some procedures utilize properties of… …   Wikipedia Bortle Dark-Sky Scale — The Bortle Dark Sky Scale is a nine level numeric measure of the night sky brightness of a particular location. It quantifies the observability of astronomical objects and the interference caused by light pollution and skyglow. John E. Bortle… …   Wikipedia Danjon scale — Two lunar eclipses in 2003; their ratings on the Danjon Scale would be roughly 2 (left) and 4 (right) The Danjon Scale of lunar eclipse brightness is a five point scale useful for measuring the appearance and luminosity of the Moon during a lunar …   Wikipedia Richter magnitude scale — Part of a series on earthquakes Types Foreshock • Aftershock • Blind thrust Doublet • Interplate • …   Wikipedia Logarithmic scale — A logarithmic scale is a scale of measurement that uses the logarithm of a physical quantity instead of the quantity itself. Presentation of data on a logarithmic scale can be helpful when the data covers a large range of values ndash; the… …   Wikipedia Seismic scale — A seismic scale is used to measure and compare the severity of earthquakes. (For a quick review, see the table of seismic scales at the end of this article.)Two fundamentally different but equally important types of scales are commonly used by… …   Wikipedia Timeline of knowledge about galaxies, clusters of galaxies, and large-scale structure — Timeline of galaxies, clusters of galaxies, and large scale structure of the cosmosPre 20th Century* 400s BC Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars, * 300s BC Aristotle believes the …   Wikipedia Ganoid scale — Ganoid Ga noid, a. [Gr. ? brightness + oid.] (Zo[ o]l.) Of or pertaining to Ganoidei. n. One of the Ganoidei. [1913 Webster] {Ganoid scale} (Zo[ o]l.), one kind of scales of the ganoid fishes, composed of an inner layer of bone, and an outer… …   The Collaborative International Dictionary of English Danjon scale —    a scale measuring the brightness (or rather, the darkness) of lunar eclipses, devised by the French astronomer André Louis Danjon (1890 1967). A table is provided …   Dictionary of units of measurement papermaking — [pā′pər māk΄iŋ] n. the making of paper papermaker n. * * * pa·per·mak·ing (pāʹpər mā kĭng) n. The process or craft of making paper.   paʹper·mak er n. * * * Introduction       formation of a matted or felted sheet, usually of cellulose fibres,… …   Universalium 16+


Mesothelioma, a rare form of cancer that develops from the protective lining of the body's internal organs (the mesothelium) is usually caused by exposure to what substance?

Mesothelioma Info skip to main | skip to sidebar Mesothelioma Info Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium. It is usually caused by exposure to asbestos. Helping Children Cope With Violence Witnessing violence on television or video games really pales in comparison to witness violence in real life situations. Children who are victims of violence such as shootings district, abusive parents, bullying at school, and so on, they may develop symptoms of post-traumatic stress disorder, commonly known as PTSD. PTSD leads to poor grades, difficulty concentrating, severe depression, sometimes suicidal, if not adequately control coping. Children who have witnessed violence in real life are in grave danger of mentally and emotionally. Psychologists use a special training method called cognitive behavioral therapy "to teach children the skills necessary to cope with violence. It is not as difficult as it sounds, and many psychologists are trained in the methods of cognitive behavioral therapy. In fact, parents and teachers, these methods all the time without knowing it because there are many sensible ways to educate children who handle difficult situations. Coping Skill # 1: Facing fear in a safe environment Children who do not have to internalize those fears that can destroy their self-image development. These fears must be addressed in a secure environment in support of an adult who can act with a child to understand the fear. For example, if a child is afraid to go to school because of violence created by bullies, an adult can take the child to talk about their feelings. Identify triggers, such as seeing a child who bullies the other children walking alone in the school hall or home, or hear the bell for lunch, helps children and adults to spread fear and understand what is going on in their heads and hearts. Coping skills, children learn through this exercise is the way to distinguish between situations that pose a real threat and situations that do not compromise, but to instill fear. imaginary threats can be resolved through the internal forces of the child. Really bad situations should be resolved through other interventions. Their ability to adapt # 2: A solution of social problems from If children are abused, they may have problems with their peers and adults because of the good models of effective social interaction does not exist in their world. Even small conflicts can cause outbreaks. Cognitive behavioral therapists teach children to manage social interactions. The therapist begins with examples such as stories that problem situations in detail. The child is asked leading questions about how the characters have to solve the problem peacefully. Through these learning exercises, which leads the adult child, considering all sides of the situation before deciding on action. Adequate social problem-solving skills can help children avoid violence, but will certainly help the child to control their reaction to violence if it occurs. There are situations where adaptability not avoid conflict, but most of the time problems can be resolved peacefully. Adaptation Strategy # 3: Create a support network for children Ideally, the child's parents or guardians are actively involved in all efforts to help children cope with violence. This type of support network in which everyone strives towards the goal of a healthy child is much more effective than just teaching a child some strategies, and set him free. All the teaching, who has taught professional should be transferred to the child's daily life. Here is a support network to improve the management of adults with experience and encourages children to think for themselves and solve problems. The support network also provides security for the child. He knows where to go if the only solution is to avoid a violent confrontation. He also knows where to go if fear and conflict becomes unmanageable. These caring adults should never put the baby down t


Which lady physicist was part of the team that discovered nuclear fission for which her colleague Otto Hahn won the Nobel and is often mentioned as the most glaring example of womens scientific achievement overlooked by the Nobel committee?

1000+ images about Delicate Particle Logic on Pinterest | Left out, Otto hahn and Organic chemistry Forward Lise Meitner was a physicist who was part of the team that discovered nuclear fission. Her colleague, Otto Hahn, was awarded the Nobel Prize and many believe Meitner is one of the most glaring examples of women's scientific achievement overlooked by the Nobel committee. When she was invited to join the Manhattan Project her response was "I will have nothing to do with a bomb!" See More


Named for a scientist who discovered it in 1961, what is the term for the number of times a normal cell population will divide before it stops?

Telomeres, Aging & fountain of youth Espanol video de telomeros [ 1:17 mns ]: Telomeros, Envejecimiento Celular - Maria Blasco Telomeres:  Telomeres are the protective physical caps or ends of the chromosomes and consist of repeated blocks of the DNA sequence, TTAGGG.    The  telomere protective cap [ shown in red in the right illustration ] is at the end of each of the 24 chromosomes [ light blue in the illustration ].  Telomere function: Telomeres protect the chromosome from fusing with another and also preventing mutations in DNA. Dr. Bill Andrews 69   has evolved an animation to help us understand how telomeres and aging work.  His analogy is to "think of a DNA as a long row of bricks, and of DNA replication as a bricklayer walking backwards on top of a brick wall laying a new layer on top of that row. When the end of the wall is reached, the bricklayer finds himself standing on top of the brick he's supposed to replicate. Since he can't put down a brick where his feet are, he steps back and falls off the wall ---- leaving the very end of the wall bare. As a result, the new copy of the wall is shorter." Just like this brick wall was copied imperfectly, our DNA in a telomere is unable to perfectly copy itself; when a strand is replicated, the new strand is shorter than the old strand. If we lost portions of the information encoded in our DNA every time it replicated, human life would be impossible. Our cells couldn't even divide enough times to allow us to be born. Fortunately, we are born with long, repetitive sequences of DNA at the end of each of our chromosomes, which later shorten during the normal DNA replication process." 69   These repetitive sequences are called "telomeres." Telomeres function by preventing chromosomes from losing base pair sequences [ TTAGGG ] at their ends.  Telomeres protect the chromosome from fusing with another and also preventing mutations in DNA. Telomeres become shorter each time cells divide.   When we are first conceived, the telomeres in our reproductive single-cell embryos are approximately 15,000 nucleotides long. Our cells divide rapidly in the womb, and by the time we are born, our telomeres have decreased in length to approximately 10,000 nucleotides. Each time a cell divides, some of the telomere is lost ( [ usually 25-200 base pairs per division ]. They shorten throughout our lifetime.   When the telomere becomes too short, the chromosome reaches a "critical length" and can no longer replicate. This means that a cell becomes "old" and dies. 3   This wearing out with age process was discovered by DNA researcher, Leonard Hayflick in the 1960s, as the number of times a normal cell population will divide before it stops. Hayflick discovered that non-stem [ i.e. non-telomerase active ] cells in a dish can only divide about 60 times before the telomeres become too short to survive. The limit on a cellâs maximum lifespan is known as its " Hayflick Limit .â  When the telomere is depleted, the cell dies. 4   However, telomere life may be extended by an enzyme telomerase.   Unfortunately, the part of the DNA that produces telomerase is asleep in our bodies, i.e. the âswitchâ is turned off. We now have the ability to turn the âswitchâ back on to produce telomerase, which can then restore and repair the lengths of the ends of your DNA. The result is a healthier DNA and potentially a reversal of the aging process. Telomerase adds repetitive DNA TTAGGG sequences to telomeres. Instead of gradually getting older and dying, the cells continue living indefinitely. The video below summarizes how telomerase works:   [ Flash Player may be required to view the animations.]  Source: Telomerase function Telomerase prevents DNA strands from shortening, allowing perfect cells to replicate again and again. Telomerase does this by adding repetitive sequences [nucleotides] to the ends of our chromosomes, thus lengthening our telomeres. Telomerase works by filling the "gap" left by DNA replication thereby lengthening telomeres.  This is illustrated [ below l


"""I am become Death, the shatterer of Worlds."" This quote from the Hindu treatise Bhagavad Gita was famously used at what 1945 event?"

quoting the Bhagawad Gita J.Robert Oppenheimer Quotes - Quotations Book Authors starting with Q Quotes by quoting the Bhagawad Gita J.Robert Oppenheimer J.Robert Oppenheimer : Julius Robert Oppenheimer (April 22, 1904 – February 18, 1967) was an American theoretical physicist and professor of physics at the University of California, Berkeley. He is best known for his role as the scientific director of the Manhattan Project, the World War II project that developed the first nuclear weapons, for which he is often referred to as the "father of the atomic bomb". In reference to the Trinity test in New Mexico, where the first atomic bomb was detonated, Oppenheimer famously recalled the Bhagavad Gita: "If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one." and "Now I am become Death, the destroyer of worlds." ...


There is no such thing as knowing this a little. The 'rabbit test' developed in 1927 by Bernhard Zondek and Selmar Aschheim was used to check for what?

Project MUSE - "A Private Little Revolution": The Home Pregnancy Test in American Culture The Home Pregnancy Test in American Culture Sarah A. Leavitt Abstract The home pregnancy test went from novelty to norm in twenty-five years. This article explores its cultural impact in the context of the women's health movement. Though women had long made do without it, the "private little revolution," as the test was called in an early advertisement, enabled them to take control of their reproductive health care and moved the moment of discovery from the doctor's office (back) to the home. The article introduces the test, explores its acceptance by physicians and by women, looks at the marketing of the test by drug companies, and traces its use in movies, television, and novels. Keywords home pregnancy test, women's health movement, hCG, online survey The e.p.t In-Home Early Pregnancy Test is a private little revolution any woman can easily buy at her drugstore. 1 In March 1978, readers of Mademoiselle found an unusual notice among the mundane assortment of articles on clothing, hairstyles, and relationship advice. Trumpeting a "private little revolution," the advertisement [End Page 317] took up an entire page and featured an image of the apparatus needed to complete the featured procedure, which turned out to be a home pregnancy test. Using scientific language to impress readers with the technology gleaned from "many years of costly research," the text of the advertisement emphasized that the allure of the test was the power of knowledge: "At last," it claimed, "early knowledge of pregnancy belongs easily and accurately to us all." 2 This populist message, coupled with the opening salvo of "revolution," indicated that the marketers of this product were selling more than a plastic test tube: they were promoting a new understanding of pregnancy. "Now, when you call your doctor, you have the results of your test to report," the advertisement concluded, "and time is on your side at last." 3 The home pregnancy test, introduced to American consumers with advertisements like this one in the late 1970s, changed women's relationship with the early knowledge of pregnancy and thus became a part of late twentieth-century reproductive health. Before the widespread use of the test, pregnancy was diagnosed either by waiting for "natural" signs or by a doctor; today, millions of women discover their pregnancies in the privacy of their homes. Scholars have covered much ground in understanding the larger context of the women's health movement, from Sue Rosser's treatment of the ways in which women had been summarily left out of much health-related research to Sandra Morgen's exploration of how women's political involvement in local health clinics and elsewhere changed mainstream medicine. 4 The home pregnancy test forged a much smaller revolution, and can serve as an important example of the impact of the women's health movement by illuminating an area in which women assumed control of knowledge that had previously been in the hands of their doctors. It is an example of the reversing of the medicalization of pregnancy, in fact, for this is a diagnosis that was once in the hands of women and, in the late twentieth century, was returned there. Though the test results will lead most women to the medical establishment—if the test is positive, most will either have an abortion or begin prenatal care—the test returned the moment of discovery to the home, where it had been before the mid-twentieth century moved it to the doctor's office. It is its reconfiguration of the locus of control at the moment of discovery that makes the pregnancy test into a "revolution." [End Page 318] The history of the pregnancy test can also help us understand the history of reproductive technologies, a rich field of inquiry. As technology goes, the test is relatively simple: it can deliver only one of two answers (yes or no), and describes a situation that has already come to pass. Indeed, the feminist writer Naomi Wolf has described taking the test as a kind of "fatalism"


Used in medical talk (think PET or CAT), what is the name given to a two-dimensional image of a slice through a three-dimensional object?

Magnetic resonance imaging | definition of magnetic resonance imaging by Medical dictionary Magnetic resonance imaging | definition of magnetic resonance imaging by Medical dictionary http://medical-dictionary.thefreedictionary.com/magnetic+resonance+imaging Related to magnetic resonance imaging: functional magnetic resonance imaging Magnetic Resonance Imaging   Definition Magnetic resonance imaging (MRI) is the newest, and perhaps most versatile, medical imaging technology available. Doctors can get highly refined images of the body's interior without surgery, using MRI. By using strong magnets and pulses of radio waves to manipulate the natural magnetic properties in the body, this technique makes better images of organs and soft tissues than those of other scanning technologies. MRI is particularly useful for imaging the brain and spine, as well as the soft tissues of joints and the interior structure of bones. The entire body is visible to the technique, which poses few known health risks. Purpose MRI was developed in the 1980s. The latest additions to MRI technology are angiography (MRA) and spectroscopy (MRS). MRA was developed to study blood flow, while MRS can identify the chemical composition of diseased tissue and produce color images of brain function. The many advantages of MRI include: Detail. MRI creates precise images of the body based on the varying proportions of magnetic elements in different tissues. Very minor fluctuations in chemical composition can be determined. MRI images have greater natural contrast than standard x rays, computed tomography scan (CT scan), or ultrasound, all of which depend on the differing physical properties of tissues. This sensitivity lets MRI distinguish fine variations in tissues deep within the body. It also is particularly useful for spotting and distinguishing diseased tissues (tumors and other lesions) early in their development. Often, doctors prescribe an MRI scan to more fully investigate earlier findings of the other imaging techniques. Scope. The entire body can be scanned, from head to toe and from the skin to the deepest recesses of the brain. Moreover, MRI scans are not obstructed by bone, gas, or body waste, which can hinder other imaging techniques. (Although the scans can be degraded by motion such as breathing, heartbeat, and normal bowel activity.) The MRI process produces cross-sectional images of the body that are as sharp in the middle as on the edges, even of the brain through the skull. A close series of these two-dimensional images can provide a three-dimensional view of a targeted area. Safety. MRI does not depend on potentially harmful ionizing radiation, as do standard x-ray and CT scans. There are no known risks specific to the procedure, other than for people who might have metal objects in their bodies. MRI is being used increasingly during operations, particularly those involving very small structures in the head and neck, as well as for preoperative assessment and planning. Intraoperative MRIs have shown themselves to be safe as well as feasible, and to improve the surgeon's ability to remove the entire tumor or other abnormality. Given all the advantages, doctors would undoubtedly prescribe MRI as frequently as ultrasound scanning, but the MRI process is complex and costly. The process requires large, expensive, and complicated equipment; a highly trained operator; and a doctor specializing in radiology. Generally, MRI is prescribed only when serious symptoms and/or negative results from other tests indicate a need. Many times another test is appropriate for the type of diagnosis needed. Doctors may prescribe an MRI scan of different areas of the body. Brain and head. MRI technology was developed because of the need for brain imaging. It is one of the few imaging tools that can see through bone (the skull) and deliver high quality pictures of the brain's delicate soft tissue structures. MRI may be needed for patients with symptoms of a brain tumor , stroke, or infection (like meningitis ). MRI also may be needed when cognitive and/or psychol


In chemistry, what is the common name for the alkane hydrocarbons with the general formula C(n)H(2n+2), the simplest form of which is the methane (CH4) gas?

Organic Chemistry/Alkanes - Wikibooks, open books for an open world Organic Chemistry/Alkanes Jump to: navigation , search Alkanes are the simplest organic molecules, consisting of only carbon and hydrogen and with only single bonds between carbon atoms. Alkanes are used as the basis for naming the majority of organic compounds (their nomenclature). Alkanes have the general formula CnH2n+2. Contents 2,2-dimethylpropane or neopentane. An example of an alkane Alkanes are the simplest and least reactive hydrocarbon species containing only carbons and hydrogens. They are commercially very important, being the principal constituent of gasoline and lubricating oils and are extensively employed in organic chemistry; though the role of pure alkanes (such as hexanes) is delegated mostly to solvents. The distinguishing feature of an alkane, making it distinct from other compounds that also exclusively contain carbon and hydrogen, is its lack of unsaturation . That is to say, it contains no double or triple bonds, which are highly reactive in organic chemistry. Though not totally devoid of reactivity, their lack of reactivity under most laboratory conditions makes them a relatively uninteresting, though very important component of organic chemistry. As you will learn about later, the energy confined within the carbon-carbon bond and the carbon-hydrogen bond is quite high and their rapid oxidation produces a large amount of heat, typically in the form of fire. As said it is important, not considered very important component in the chemistry. Introductory Definitions[ edit ] Organic compounds contain carbon and hydrogen by definition and usually other elements (e.g. nitrogen and oxygen) as well. (CO2 is not an organic compound because it has no hydrogen). Hydrocarbons are organic compounds that contain carbon and hydrogen only. Alkanes are hydrocarbons or organic compounds made up of only carbon-carbon single bonds (as opposed to double and triple bonds). The simplest alkane is methane . Methane, (CH4, one carbon bonded to four hydrogens) is the simplest organic molecule. It is a gas at standard temperature and pressure (STP) . Methane This is a flattened, two-dimensional representation of methane that you will see commonly. The true three-dimensional form of methane does not have any 90 degree angles between bonded hydrogens. The bonds point to the four corners of a tetrahedron , forming cos-1(-1/3) ≈ 109.5 degree bond angles. A balloon model of the electron clouds repelling each other in a molecule of methane. Ethane[ edit ] Two carbons singly bonded to each other with six hydrogens is called ethane . Ethane is the second simplest hydrocarbon molecule. It can be thought of as two methane molecules attached to each other, but with two fewer hydrogen atoms. There are several common methods to draw organic molecules. You will use them interchangeably although sometimes one will work better for one situation or another. Drawing alkanes[ edit ] When writing out the alkane structures, you can use different levels of shorthand depending on the needs at hand in hand. For example, pentane can be written out. Its formula is C5H12. , or CH3–CH2–CH2–CH2–CH3, or CH3(CH2)3CH3, or minimized to Line drawing shorthand[ edit ] Although non-cyclic alkanes are called straight-chain alkanes they are technically made of linked chains. This is reflected in the line-drawing method. Each ending point and bend in the line represents one carbon atom and each short line represents one single carbon-carbon bond. Every carbon is assumed to be surrounded with a maximum number of hydrogen atoms unless shown otherwise. Propane, butane, pentane Structures drawn without explicitly showing all carbon atoms are often called "skeletal" structures, since they represent the skeleton or the backbone of the molecule. In organic chemistry, carbon is very frequently used, so chemists know that there is a carbon atom at the endpoints of every line that is not specifically labeled. Conformations[ edit ] Conformers, also called conformational isomers, or rotational isomers,or r


Were he alive in 2006, the American astronomer Clyde Tombaugh would have been disappointed as his discovery was 'dwarfed.' What did he discover in 1930?

Learn and talk about Clyde Tombaugh, American Unitarian Universalists, American astronomers, Discoverers of asteroids, Discoverers of trans-Neptunian objects 10 External links Life and career[ edit ] Tombaugh was born in Streator, Illinois , the son of Adella Pearl (Chritton) and Muron Dealvo Tombaugh, a farmer. [1] After his family moved to Burdett, Kansas in 1922, Tombaugh's plans for attending college were frustrated when a hailstorm ruined his family's farm crops. [2] Starting in 1926, he built several telescopes with lenses and mirrors by himself. [2] In order to better test his telescope mirrors, Tombaugh, with just a pick and shovel, dug a pit 24 feet long, 8 feet deep, and 7 feet wide. This cave provided a constant air temperature, free of air currents. It was also used by the family as a root cellar and emergency shelter. [3] He sent drawings of Jupiter and Mars to the Lowell Observatory , which offered him a job. [4] Tombaugh worked there from 1929 to 1945. Following his discovery of Pluto, Tombaugh earned bachelor's and master's degrees in astronomy from the University of Kansas in 1936 and 1938. [2] During World War II he taught naval personnel navigation at Northern Arizona University . [2] He worked at White Sands Missile Range in the early 1950s, and taught astronomy at New Mexico State University from 1955 until his retirement in 1973. The asteroid 1604 Tombaugh , [5] discovered in 1931, is named after him. He discovered hundreds of asteroids, beginning with 2839 Annette in 1929, mostly as a by-product of his search for Pluto and his searches for other celestial objects. [2] Tombaugh named some of them after his wife, children and grandchildren. The Royal Astronomical Society awarded him the Jackson-Gwilt Medal in 1931. [6] In 1980, he wrote a book "Out of the Darkness:The Planet Pluto" with Patrick Moore . [7] In August 1992, JPL scientist Robert Staehle called Tombaugh, requesting permission to visit his planet. "I told him he was welcome to it," Tombaugh later remembered, "though he's got to go one long, cold trip." [8] The call eventually led to the launch of the New Horizons space probe to Pluto in 2006. Following the passage on July 14, 2015 of Pluto by the New Horizons spacecraft the "Cold Heart of Pluto" was named Tombaugh Regio . Death[ edit ] Tombaugh died on January 17, 1997, when he was in Las Cruces, New Mexico , at the age of 90. A small portion of his ashes was placed aboard the New Horizons spacecraft. The container includes the inscription: "Interred herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system's 'third zone'. Adelle and Muron's boy, Patricia's husband, Annette and Alden's father, astronomer, teacher, punster, and friend: Clyde W. Tombaugh (1906–1997)". [9] Tombaugh was survived by his wife, Patricia (1912–2012), and their children, Annette and Alden. [10] Religion[ edit ] Tombaugh was an active Unitarian-Universalist , and he and his wife helped found the Unitarian Universalist Church of Las Cruces, New Mexico. [11] Family[ edit ] Through the daughter of his youngest brother, Robert M., Tombaugh is the great uncle of Los Angeles Dodgers pitcher Clayton Kershaw . [12] Discovery of Pluto[ edit ] Tombaugh created his photographic plates using this 13-inch astrograph While a young researcher working for the Lowell Observatory in Flagstaff, Arizona , Tombaugh was given the job to perform a systematic search for a trans-Neptunian planet (also called Planet X ), which had been predicted by Percival Lowell and William Pickering . Tombaugh used the observatory's 13-inch astrograph to take photographs of the same section of sky several nights apart. He then used a blink comparator to compare the different images. When he shifted between the two images, a moving object, such as a planet, would appear to jump from one position to another, while the more distant objects such as stars would appear stationary. Tombaugh noticed such a moving object in his search, near the place predicted by Lowell, and subsequent observations showed it to have an orbit beyon


What non-technical term is given to a condition where the thumb, when extended (as in a 'thumbs-up'), stretches backwards toward the nail and outwards?

Thumb Tendonitis or Thumb Tenosynovitis? Shooting Pain In The Thumb Thumb Tendonitis or Thumb Tenosynovitis? Shooting Pain In The Thumb by Mark (Santa Ana, CA) I have a shooting pain in my thumb when I do certain activities involving grabbing something. There is no swelling or pain under normal movement but when I stretch the thumb or use it to grab the dog leash for instance, I get a severe shooting pain radiating from the base to the tip. Do I need to see my doctor or a specialist? Thanks, Well, I've never ever told someone they shouldn't see doctor. There could be all sorts of weird, rare medical issues causing that. Still, chances are good that you have some thumb specific Tendonitis or Tenosynovitis . Heeeellllllooooo Pain Causing Dynamic ! So, let's investigate. Questions: 1. Describe the pain, in as great a detail as possible. Just in the thumb? Up the arm? Wrist? Hand? General pain, or could you clearly identify a sharp time. 2. What do you do with your hands all day long? Computer? Musician? Video games? Lots of texting on the cell phone? 3. Other thumb is fine? 4. History of injury or pain? 5. Age? 6. Is there a specific direction of movement that hurts it, but others don't, or do many kinds/angles/directions of movement. Pushing, pulling, thumbs up, pushing against a wall with the thumb in various ways, etc. 7. If you poke around the area, is there a hot spot? Are the muscles in the forearm, thumbpad, etc, sore, painful, or tight? I'm guessing that there is a line of muscle in your thumb pad that is PAINFUL if you press on it. Answer those questions, and let's go from there. ---------------------- Please reply using the comment link below. Do not submit a new submission to answer/reply, it's too hard for me to find where it's supposed to go. And, comments have a 3,000 character limit so you may have to comment twice. -----------------------


What is a type of chemical mixture where one substance is dispersed evenly throughout another?

Chemistry for Kids: Chemical Mixtures Chemistry for Kids Chemical Mixtures One of the main aspects of chemistry is combining different substances. Sometimes combining substances can cause a chemical reaction and bonding which creates an entirely new substance called a compound. However, sometimes there is no chemical reaction or bonding. In this case, a mixture is formed from the combined substances. Mixture A mixture is made when two or more substances are combined, but they are not combined chemically. General properties of a mixture: The components of a mixture can be easily separated The components each keep their original properties The proportion of the components is variable Types of Mixtures There are two main categories of mixtures: homogeneous mixtures and heterogeneous mixtures. In a homogenous mixture all the substances are evenly distributed throughout the mixture (salt water, air, blood). In a heterogeneous mixture the substances are not evenly distributed (chocolate chip cookies, pizza, rocks) Within the categories of homogeneous and heterogeneous mixtures there are more specific types of mixtures including solutions, alloys, suspensions, and colloids. Solutions (homogeneous) A solution is a mixture where one of the substances dissolves in the other. The substance that dissolves is called the solute. The substance that does not dissolve is called the solvent. An example of a solution is salt water. These components can be easily separated through evaporation and they each retain their original properties. However, the salt is dissolved into the water to where you can't see it and it is evenly distributed in the water. In this example the water is the solvent and the salt is the solute. What is the difference between a solution and a mixture? In chemistry a solution is actually a type of mixture. A solution is a mixture that is the same or uniform throughout. Think of the example of salt water. This is also called a "homogenous mixture." A mixture that is not a solution is not uniform throughout. Think of the example of sand in water. This is also called a "heterogeneous mixture." Alloys (homogeneous) An alloy is a mixture of elements that has the characteristic of a metal. At least one of the elements mixed is a metal. One example of an alloy is steel which is made from a mixture of iron and carbon. Suspensions (heterogeneous) A suspension is a mixture between a liquid and particles of a solid. In this case the particles do not dissolve. The particles and the liquid are mixed up so that the particles are dispersed throughout the liquid. They are "suspended" in the liquid. A key characteristic of a suspension is that the solid particles will settle and separate over time if left alone. An example of a suspension is a mixture of water and sand. When mixed up, the sand will disperse throughout the water. If left alone, the sand will settle to the bottom. Colloids (heterogeneous) A colloid is a mixture where very small particles of one substance are evenly distributed throughout another substance. They appear very similar to solutions, but the particles are suspended in the solution rather than fully dissolved. The difference between a colloid and a suspension is that the particles will not settle to the bottom over a period of time, they will stay suspended or float. An example of a colloid is milk. Milk is a mixture of liquid butterfat globules dispersed and suspended in water. Colloids are generally considered heterogeneous mixtures, but have some qualities of homogeneous mixtures as well. Interesting Facts about Mixtures Smoke is a mixture of particles that are suspended in the air. Tap water is a mixture of water and other particles. Pure water or H2O is generally referred to as distilled water. Many of the substances we come into contact with every day are mixtures including the air we breathe which is a mixture of gases like oxygen and nitrogen. Blood is a mixture that can be separated by a machine called a centrifuge into its two main parts: plasma and red blood cells. Mixtures can be liquids, gases,


Literally meaning 'on the kidney', what hormone that participates in the 'fight or flight' response of the body is produced by the adrenal glands?

Fight or Flight - How Fear Works | HowStuffWorks Fight or Flight   Prev Next   To produce the fight-or-flight response, the hypothalamus activates two systems: the sympathetic nervous system and the adrenal-cortical system. The sympathetic nervous system uses nerve pathways to initiate reactions in the body, and the adrenal-cortical system uses the bloodstream. The combined effects of these two systems are the fight-or-flight response. When the hypothalamus tells the sympathetic nervous system to kick into gear, the overall effect is that the body speeds up, tenses up and becomes generally very alert. If there's a burglar at the door, you're going to have to take action -- and fast. The sympathetic nervous system sends out impulses to glands and smooth muscles and tells the adrenal medulla to release epinephrine (adrenaline) and norepinephrine (noradrenaline) into the bloodstream. These "stress hormones" cause several changes in the body, including an increase in heart rate and blood pressure . Up Next This is your brain on love: The Science of Love Quiz At the same time, the hypothalamus releases corticotropin-releasing factor (CRF) into the pituitary gland, activating the adrenal-cortical system. The pituitary gland (a major endocrine gland ) secretes the hormone ACTH (adrenocorticotropic hormone). ACTH moves through the bloodstream and ultimately arrives at the adrenal cortex, where it activates the release of approximately 30 different hormones that get the body prepared to deal with a threat. The sudden flood of epinephrine, norepinephrine and dozens of other hormones causes changes in the body that include: heart rate and blood pressure increase pupils dilate to take in as much light as possible veins in skin constrict to send more blood to major muscle groups (responsible for the "chill" sometimes associated with fear -- less blood in the skin to keep it warm) blood-glucose level increases muscles tense up, energized by adrenaline and glucose (responsible for goose bumps -- when tiny muscles attached to each hair on surface of skin tense up, the hairs are forced upright, pulling skin with them) smooth muscle relaxes in order to allow more oxygen into the lungs nonessential systems (like digestion and immune system ) shut down to allow more energy for emergency functions trouble focusing on small tasks (brain is directed to focus only on big picture in order to determine where threat is coming from) All of these physical responses are intended to help you survive a dangerous situation by preparing you to either run for your life or fight for your life (thus the term "fight or flight"). Fear -- and the fight-or-flight response in particular -- is an instinct that every animal possesses.


Woods Hole, Massachusetts is famous for having many institutes in what field of science?

Woods Hole, Massachusetts - HopAmerica.com Massachusetts Author Aleksandar Stevanović data-ad-client="ca-pub-3747382384838434"   data-ad-slot="3711430146"> “Equipped with his five senses, man explores the universe around him and calls the adventure Science.” – Edwin Hubble Attribution Some Rights Reserved By Putneypics How would you define charm? Would you say it’s a characteristic of a person you like? Someone you like so much that you’re more than happy to refer to them as charming? Or, is it a more elusive notion? Places can be charming, too. We must have written about dozens of incredibly charming places before. Is it, perhaps, a term you would use to describe that pleasant, yet mysterious feeling you get whenever you’re in the company of an attractive person or an unusual place? We would say both, actually. But the kind of charm we’re talking about here is not one we’ve written about before. We know what you’re going to say: “you already said that many places are charming, what are you on about now”? Well, what we’re referring to is a special kind of charm. A, sort of, addiction, if you will. But for the most part, you’re right. We are talking about a particular place. What might, but shouldn’t surprise you when it comes to this place is the fact that it’s a small town. We love to write about these places because they’re special in their own, hidden kind of way. However, Woods Hole, Massachusetts is a small town unlike any you’ve ever experienced before, and neither have we. Attribution Some Rights Reserved By Vince Smith You also know that we love to write about not so familiar places because they have a lot to offer. And wait till you get a load of everything Woods Hole has to offer! A place so packed with history, knowledge, experience and beauty that it almost sounds like a breathtaking illusion. When you consider what life is like in major metropolis areas in the country, this picturesque town almost feels like a gift from the heavens. With a population of just over 700, you can imagine the peace and serenity of Woods Hole without even visiting the place. However, you’d be passing up an awesome opportunity by doing that. An opportunity to experience the true spirit of knowledge that has been preserved for more than a century and a half. You’ve probably noticed that we keep mentioning knowledge as an important aspect of this place. But, more on that later. For now, we’ll say that Woods Hole is officially classified as a CDP (census-designated place) in Barnstable County. More accurately, it’s in the town of Falmouth, but Woods Hole is a far better known designation than either of the aforementioned. The Cape Cod’s extreme southwest corner is its home, near the Elizabeth Islands and Martha’s Vineyard. Attribution Some Rights Reserved By Katja Schulz If you were to ask us what sets Woods Hole apart from other towns in Cape Cod, it would be really difficult to choose just one answer, but we would have to go with – science. The place is simply incredible when you look at the number of scientific and research institutions in it. For example, one of the places that allows you to get really up close and personal with what we’ve just mentioned is the Marine Biological Laboratory. Founded in 1888, this amazing Woods Hole institution has over 2000 employees during its summer programs, as opposed to the “mere” 300 who work there year-round. It comes as no surprise that a number of Nobel laureates also have a home in the Laboratory. Should you choose to visit this bastion of knowledge, which is something we definitely recommend, you will be granted access to the Robert W. Pierce Exhibit Center, lectures at the Falmouth Forum, as well as many interesting and very detailed tours.   It would be just wrong to mention Woods Hole and not turn your attention to the Woods Hole Oceanographic Institution, yet another giant when it comes to science. The importance of this powerhouse lies in the fact that, since 1930, it has been at the very core of marine engineering and exploration. In fact, here’s one you probably didn’t know: in


Meaning 'indicator' in Greek, what is the part of a sundial that casts the shadow called?

the-parts-of-a-sundial A sundial has a shadow casting device called a gnomon, attached to a dial plate which has markings. The actual shadow used to read the time is created by a part of the gnomon called the"style".   The markings almost always have hours, and may or may not be legal clock mean time, often it is local sun time.   Local sun time (local apparent time or L.A.T.) must have the longitude factored in, typically somewhere between -30 to +30 minutes. Also, the clock and the sun are not in synch, the difference is called the equation of time ( EOT ) and varies predictably throughout the year, the limits being about plus or minus 16 minutes. Other markings may appear on a sundial, the date ( declination lines or curves ) is common. Sometimes the hours until the next sunset ( Italian lines ) is another. Yet another is the Islamic prayer times. The analemma , and so on. The markings have hour lines or hour points, and sometimes calendar information and the like, collectively called dial furniture. Calendar lines may show specific dates, or the solstice and the equinoxes. The dial furniture is marked on the dial plate.


In 1931, the American physical chemist Harold Urey demonstrated the existence of what type of 'weighty' liquid that proved important in the development of the atomic bomb?

The Militant Atheist: The Making of the Atomic Bomb ---------------------------------------     |                   |     |  The Making of the Atomic Bomb  |     |     Richard Rhodes       |     |                   |     |-------------------------------------|     |                   |     |  Created:      08/16/2007  |     |                   |     |  Last modified:   08/17/2007  | |                   |     --------------------------------------- We must be curious to learn how such a set of objects - hundreds of power plants, thousands of bombs, tens of thousands of people massed in national establishments -- can be traced back to a few people sitting at laboratory benches discussing the peculiar behaviour of one type of atom.          Spencer R. Weart The atomic bomb and the subsequent hydrogen bomb were inventions that were made before we understood what it was we were making. For better or worse, we cannot forsee the consequences of our technological progress. The first subway on the European continent was dug not in Paris or Berlin, but in Budapest. On November 8, 1895, German physicist Wilhelm Rontgen discovered X-rays radiating from the fluorescing glass wall of a cathode-ray tube. In 1897, he identified what he called the "negative" corpuscle, the electron, and the first atomic particle to be identified. In 1898, Madamme Curie had discovered the radioactive element she called Polonium, after her native country of Poland. In 1907, Albert Einstein derived his famous equation E = MC**2. If the speed of light is a constant, then something else must serve as the elastic between two systems at motion in relation to one another - even if that something else is time. If a body gives off an amount E of energy its mass minutely diminishes. But if energy has mass, then mass must have energy: the two must be equivalent: E = MC**2, E/C**2 = M (i.e. an amount of energy E in joules is equal to an amount of mass M in kilograms multiplied by the square of the speed of light, an enormous number, 3 x 10**8 meters per second times 3 x 10**8 m/s = 9 x 10**16 or 90,000,000,000,000,000 joules per kilogram. Dividing E by C**2 demonstrates how large an amount of energy is contained even in a small mass. In 1908, Hans Geiger and Ernest Rutherford devised the Geiger counter. In 1914, H.G. Wells published the book "The World Set Free" and predicted atomic bombs. Out of the prospering but vulnerable Hungarian Jewish middle class came no fewer than seven of the twentieth century's most exceptional scientists, in order of birth, Theodor Von Karman, George de Hevesy, Michael Polanyi, Leo Szilard, Eugene Wigner, John von Neuman and Edward Teller. The mystery of such a concentration of ability from so remote and provincial a place has fascinated the community of science. It was like a group of men from Mars had arrived. In October of 1918, Hungary suffered a revolution and the Republic of Hungary was announced on November 16, 1918. On November 20, 1918, the Hungarian Communist party formed and on March 21, 1919, the Republic of Hungary bloodlessly metamorphosed into the Hungarian Soviet Republic. One hundred and thirty three (133) days later, the White Terror of the Horthy regime moved in and installed a violent fascist anti-semitic regime. In 1918, Francis William Aston invented the mass-spectograph which sorted elements and isotopes of elements by mass. It used mixed nuclei projected in a radiant beam through a magnetic field which would bend into separated component beams according to their velocity, which gave a measure of their mass. An electrostatic field bent the component beams differently depending on their electrical discharge which gave a measure of their atomic number. In 1919, Ernest Rutherford achieved the first artificial transmutation (sort of a split) of an atom. In the summer of 1921, a wealthy seventeen-year-old American student, Robert Oppenheimer was colle


Taking its name from the Latin word for magpie, what medical disorder is characterized by an appetite for non-nutritive substances (e.g., clay)?

Pica | definition of pica by Medical dictionary Pica | definition of pica by Medical dictionary http://medical-dictionary.thefreedictionary.com/pica   Definition Pica is the persistent craving and compulsive eating of nonfood substances. The Diagnostic and Statistical Manual of Mental Disorders, fourth edition, classifies it as a feeding and eating disorder of childhood. Description The puzzling phenomenon of pica has been recognized and described since ancient times. Pica has been observed in ethnic groups worldwide, in both primitive and modernized cultures, in both sexes, and in all age groups. The word pica comes from the Latin name for magpie, a bird known for its unusual and indiscriminate eating habits. In addition to humans, pica has been observed in other animals, including the chimpanzee. Pica in humans has many different subgroups, defined by the substance that is ingested. Some of the most commonly described types of pica are eating earth, soil or clay (geophagia), ice (pagophagia) and starch (amylophagia). However, pica involving dozens of other substances, including cigarette butts and ashes, hair, paint chips, and paper have also been reported. In one unusual case, the patient ingested transdermal patches of fentanyl, an opioid medication given for severe pain . Eating the skin patch increased the patient's dose of the drug by a factor of 10. Although pica can occur in individuals of any background, a higher incidence of pica is associated with: developmental delay and mental retardation psychiatric disease and autism poor nutrition or low blood levels of iron and other minerals certain cultural or religious traditions Causes and symptoms Evidence suggests that there may be several causes of pica. One widely held theory points to iron deficiency as a major cause of pica. Several reports have described pica in individuals with documented iron deficiency, although there has been uncertainty as to whether the iron deficiency was a cause of pica or a result of it. Because some substances, such as clay, are believed to block the absorption of iron into the bloodstream, it was thought that low blood levels of iron could be the direct result of pica. However, some studies have shown that pica cravings in individuals with iron deficiency stop once iron supplements are given to correct the deficiency. Another study looked specifically at the rate of iron absorption during pica conditions and normal dietary behavior, and showed that the iron absorption was not decreased by pica. In addition, low blood levels of iron commonly occur in pregnant women and those with poor nutrition, two populations at higher risk for pica. Such findings offer strong support of iron deficiency as a cause, rather than result, of pica. Other reports suggest that pica may have a psychological basis and may even fall into the spectrum of obsessive-compulsive disorder . Pica has a higher incidence in populations with an underlying diagnosis involving mental functioning. These diagnoses include psychiatric conditions like schizophrenia, developmental disorders including autism, and conditions with mental retardation. These conditions are not characterized by iron deficiency, which supports a psychological component in the cause of pica. Cultural and religious traditions may also play a role in pica behavior. In some cultures, nonfood substances are believed to have positive health or spiritual effects. Among some African Americans in the south, ingesting a particular kind of white clay is believed to promote health and reduce morning sickness during pregnancy. Other cultures practice pica out of belief that eating a particular substance may promote fertility or bring good luck. The hallmark feature of pica, consistently consuming nonfood substances, often does not present publicly. People may be embarrassed to admit to these unusual eating habits, and may hide it from their family and physician. In other cases, an individual may not report the pica to a physician simply because of a lack of knowledge of pica's potential medical significance. B


What algebraic system taught in present-day schools is one of the legacies of the philosopher René Descartes to which he lent his name?

René Descartes Explained René Descartes Explained Metaphysics , epistemology , mathematics , physics , cosmology Influences: Plato , Aristotle , Archimedes , Alhazen , Al-Ghazali , [4] Averroes , Avicenna , Anselm , Augustine , Stoics , Aquinas , Ockham , Suarez , Mersenne , Sextus Empiricus , Montaigne , Golius , Beeckman , Duns Scotus [5] Influenced: Virtually all subsequent Western philosophy , especially Spinoza , Leibniz , John Locke , Nicolas Malebranche , Jacques-Bénigne Bossuet [6] Blaise Pascal , Isaac Newton , Immanuel Kant , Johann Gottlieb Fichte , Edmund Husserl , Noam Chomsky , Slavoj Zizek , David Chalmers Notable Ideas: Cogito ergo sum , method of doubt , method of normals , Cartesian coordinate system , Cartesian dualism, foundationalism , ontological argument for the existence of God, mathesis universalis , folium of Descartes René Descartes (; [7] in French ʁəne dekaʁt/; Latinized : Renatus Cartesius; adjectival form : "Cartesian"; [8] 31 March 159611 February 1650) was a French philosopher , mathematician , and scientist . Dubbed the father of modern western philosophy, much of subsequent Western philosophy is a response to his writings, [9] which are studied closely to this day. He spent about 20 years of his life in the Dutch Republic . Descartes's Meditations on First Philosophy continues to be a standard text at most university philosophy departments. Descartes's influence in mathematics is equally apparent; the Cartesian coordinate system —allowing reference to a point in space as a set of numbers, and allowing algebraic equations to be expressed as geometric shapes in a two- or three-dimensional coordinate system (and conversely, shapes to be described as equations)—was named after him. He is credited as the father of analytical geometry , the bridge between algebra and geometry, used in the discovery of infinitesimal calculus and analysis . Descartes was also one of the key figures in the scientific revolution . Descartes refused to accept the authority of previous philosophers, and refused to trust his own senses. He frequently set his views apart from those of his predecessors. In the opening section of the Passions of the Soul , a treatise on the early modern version of what are now commonly called emotion s, Descartes goes so far as to assert that he will write on this topic "as if no one had written on these matters before". Many elements of his philosophy have precedents in late Aristotelianism , the revived Stoicism of the 16th century, or in earlier philosophers like Augustine . In his natural philosophy , he differs from the schools on two major points: First, he rejects the splitting of corporeal substance into matter and form; second, he rejects any appeal to final ends —divine or natural—in explaining natural phenomena. [10] In his theology, he insists on the absolute freedom of God's act of creation. Descartes laid the foundation for 17th-century continental rationalism , later advocated by Baruch Spinoza and Gottfried Leibniz , and opposed by the empiricist school of thought consisting of Hobbes , Locke , Berkeley , and Hume . Leibniz, Spinoza [11] and Descartes were all well-versed in mathematics as well as philosophy, and Descartes and Leibniz contributed greatly to science as well. His best known philosophical statement is " Cogito ergo sum " (French: link=no|Je pense, donc je suis; I think, therefore I am), found in part IV of Discourse on the Method (1637; written in French but with inclusion of "Cogito ergo sum") and §7 of part I of Principles of Philosophy (1644; written in Latin). [12] Life Early life Descartes was born in La Haye en Touraine (now Descartes , Indre-et-Loire ), France, on 31 March 1596. When he was one year old, his mother Jeanne Brochard died after trying to give birth to another child who also died. His father Joachim was a member of the Parlement of Brittany at Rennes . [13] René lived with his grandmother and with his great-uncle. Although the Descartes family was Roman Catholic, the Poitou region was controlled by the Protestant Huguenots. [14] In 1607


What are the four Galilean moons of Jupiter that are named after the lovers of Zeus in Greek myth?

What are the Galilean Moons? - Universe Today   Universe Today What are the Galilean Moons? Article Updated: 26 Apr , 2016 by Matt Williams It’s no accident that Jupiter shares its name with the king of the gods. In addition to being the largest planet in our Solar System – with two and a half times the mass of all the other planets combined – it is also home to some of the largest moons of any Solar planet. Jupiter’s largest moons are known as the Galileans, all of which were discovered by Galileo Galilei and named in his honor. They include Io , Europa , Ganymede , and Callisto , and are the Solar System’s fourth, sixth, first and third largest satellites, respectively. Together, they contain almost 99.999% of the total mass in orbit around Jupiter, and range from being 400,000 and 2,000,000 km from the planet. Outside of the Sun and eight planets, they are also among the most massive objects in the Solar System, with radii larger than any of the dwarf planets. Discovery: The Galileans take their name from Galileo Galilee, the famous Italian astronomer who discovered them between January 7th and 13th, 1610. Using his improved telescope , which he designed himself, he observed what he described at the time as “three fixed stars, totally invisible by their smallness”. All three of these luminous objects were close to Jupiter, and lay on a straight line through it. Subsequent observations showed that these “stars” changed position relative to Jupiter, and in a way that was inexplicable as far as the behavior of stars was concerned. On January 10th, Galileo noted that one of them had disappeared, an observation which he attributed to it being hidden behind Jupiter. Within a few days, he concluded that they were orbiting Jupiter and were in fact moons. Galileo Galilei’s telescope with his handwritten note specifying the magnifying power of the lens, at an exhibition at The Franklin Institute in Philadelphia. Credit: AP Photo/Matt Rourke By January 13th, he had discovered a fourth moon, and named them the Medicean stars, in honor of his future patron – Cosimo II de’ Medici, Grand Duke of Tuscany – and his three brothers. However, Simon Marius – a German astronomer who also claimed to have found these four moons – prescribed the names Io, Europa, Ganymede and Callisto (after Zeus’ lovers in the Greek mythology) in 1614. While these names fell out of favor for many centuries, they became commonplace by the 20th century. Together, they also became known as the Galileans, in honor of their discoverer. Io: The innermost is Io , which is named after a priestess of Hera who became Zeus’ lover. With a diameter of 3,642 kilometers, it is the fourth-largest moon in the Solar System. With over 400 active volcanoes , it is also the most geologically active object in the Solar System. Its surface is dotted with over 100 mountains, some of which are taller than Earth’s Mount Everest. This global view of Jupiter’s moon, Io, was obtained during the tenth orbit of Jupiter by NASA’s Galileo spacecraft. Credit: NASA Unlike most satellites in the outer Solar System (which are covered with ice), Io is mainly composed of silicate rock surrounding a molten iron or iron sulfide core. Io has an extremely thin atmosphere made up mostly of sulfur dioxide (SO2). Europa: The second innermost Galilean moon is Europa , which takes its name from the mythical Phoenician noblewoman who was courted by Zeus and became the queen of Crete. At 3121.6 kilometers in diameter, it is the smallest of the Galileans, and slightly smaller than the Moon. Europa’s surface consists of a layer of water surrounding the mantle which is thought to be 100 kilometers thick. The uppermost section is solid ice, while the bottom is believed to be liquid water, which is made warm due to heat energy and tidal flexing. If true, then it is possible that extraterrestrial life could exist within this subsurface ocean, perhaps near a series of deep-ocean hydrothermal vents . The surface of Europa is also one of the smoothest in the Solar System, a fact which supports the idea of liquid wat


What mathematical puzzle that consists of three pegs and a number of disks of different sizes in which the objective is to move the entire stack of disks from one peg to another is used in computer science to teach recursion to students of programming?

tower of hanoi tower of hanoi Department of Computer Science ARTIFICIAL INTELLIGENCE : CSE 452  --------------------------------------------------------------------------------------------------------------------------------------- SUBMITTED TO: RAMANDEEP SINGH SIR SUBMITTED BY: PIYUSH RANARA1803A32 10803036    Tower of Hanoi The Tower of Hanoi or Towers of  Hanoi is a mathematical game or   puzzle . It consists of three rods, and a number of disks of different sizes which can slide ontoany rod. The puzzle starts with the disks in a neat stack in ascending order of sizeon one rod, the smallest at the top, thus making a conical shape.The objective of the puzzle is to move the entire stack to another rod, obeying thefollowing rules:  Only one disk may be moved at a time.  Each move consists of taking the upper disk from one of the rods and slidingit onto another rod, on top of the other disks that may already be present on thatrod.   No disk may be placed on top of a smaller disk.Is the end of the world near? At a monastery in the city of Hanoi, Vietnam, a groupof monks has made it their life's work to solve the Towers problem, known due toits location as the Towers of Hanoi. Legend has it that the world will end when themonks finally solve the puzzle.The puzzle is this. In the monastery are 3 pegs made of diamond. Resting on these pegs are 64 discs made of solid gold. None of the 64 discs are the same size; infact, disc 1 is slightly larger in diameter than disc 2, which is slightly larger indiameter than disc 3, which is slightly larger in diameter than disc 4, etc. Theinitial configuration of the puzzle has all 64 discs piled in order of size on the first peg with the largest disc on the bottom.   To solve the puzzle, all 64 discs must be moved to the third peg. Easy you say?The problem is that due to the fragility of the gold, you are not allowed to rest alarger disc on top of a smaller one, and only one disc may be removed from the pegs at any one time.There are many ways to solve this problem. The first is purely guess and check.Those who fear the end of the world may be hoping that the monks are using thisapproach. However, they're not; in fact, the monks all know the exact sequence of moves to solve the problem.Solving Towers of HanoiOne DiscLet's simplify the problem to clarify our thinking. Let's imagine the Towers of Hanoi problem with only one disc. About


When it launched the satellite Alouette 1 in 1962, which country became the first non-superpower to enter the space race?

PEACEKEEPING SATELLITES, III. THE TECHNOLOGY III. THE TECHNOLOGY The Case for International Surveillance and Verification A. WALTER DORN (1987) Chapter III - The Technology The technology required for a peace-keeping satellite to maintain "close-look" surveillance already exists. At this moment, several surveillance satellites, belonging to the superpowers, are orbiting the earth doing precisely that. They are able to locate objects smaller than a basketball and they can communicate the information to an earth station within seconds. The operation of these satellites has become a routine but vital part of the information gathering capabilities of the superpowers. This chapter looks at the development of surveillance satellite technology of the U.S.A., the U.S.S.R. and other nations. As background, the basic scientific principles of rocketry and satellite orbit are outlined in a section A. The important dates in the history of satellite launchings are given in Section B. The history of the American reconnaissance program is outlined in this section as well. In Section D, the civilian remote sensing satellite programs are described. Several nations are developing substantial expertise in the field of satellite remote-sensing. Canada, which began its Centre for Remote Sensing (CCRS) in 1971, has gained considerable expertise in the interpretation of remote-sensing data. The European capabilities are no less impressive. France launched its own remote sensing satellite SPOT and the data is presently being sold commercially. The European Space Agency (ESA), with its membership of eleven European nations, is planning to launch its first remote-sensing satellite in 1990, as is Japan. The technical feasibility and requirements of a peace-keeping satellite are described in section E. III. A. BACKGROUND SCIENCE Satellite Launch & Orbit In order to place a satellite into orbit, it is necessary to use rockets which can reach speeds of thousands of kilometers per hour. The rockets, therefore, usually have several stages. The booster stage brings the rocket from lift-off through a vertical phase for less than a minute. Then the rocket pitches at some angle to the vertical. Several thrust-and-coast periods follow. All the while, the used rocket stages are left to fall back to the earth. The final launch vehicle injects the satellite into its orbit. After less than two hours after launching, the satellite can have completed its first orbit. Some satellites stay in orbit for years, while others stay only for days. Earth-observation satellites travel around the earth in circular or elliptical orbits (figure 3.1) at altitudes ranging from 150 to 1000 km. At the lower distance, which is nearly one hundred miles, nominally considered the beginning of outer space, there is still some atmosphere. Photographic reconnaissance satellites often have highly elliptical orbits and may come as close as 150 km to the target area (at the "perigee" of its orbit). The 1000 km figure represents the farthest distance that most earth observation satellite may travel (the "apogee" of its orbit). The highly elliptical orbit of reconnaissance satellites minimizes atmospheric drag and thus lengthens the lifetime. For comparison, the moon, orbits at a much greater distance (380,000 km - roughly circular). Satellite orbits are often characterized by several elements. The "orbital inclination" is the angle between of the plane of the orbit and the plane of the earth's equatorial belt. The eccentricity (e) describes the shape of the orbit, whether it is highly elliptical (e near 1) or nearly circular (e=0). The semi-major axis of an ellipse is shown in figure 3.1. In elliptical satellite orbits, the earth becomes a focus point, just as the sun is a focus point for motion of the planets. The most common orbit for reconnaissance satellites is the polar orbit. Satellites travel at great speeds. Artificial satellites typically travel at 25,000 km/hr. For comparison, the moon travels at a velocity of about 3,500 km/hr (nearly a kilometer per second). Even slower, the eart