watch |
carrot |
top 10 words in brain distribution (in article): power build train water signal radio design electric state time |
top 10 words in brain distribution (in article): plant fruit produce drink grow species seed sugar leaf variety |
top 10 words in brain distribution (not in article): station species city line locomotive steam house Unite air railway |
top 10 words in brain distribution (not in article): light lamp water wine animal tree beer contain bottle time |
times more probable under watch 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under carrot (words not in the model) | |
A watch'" is a timepiece that is made to be worn on a person. The term now usually refers to a "wristwatch", which is worn on the wrist with a strap or bracelet. In addition to the time, modern watches often display the day, date, month and year, and electronic watches may have many other functions. Most inexpensive and medium-priced watches used mainly for timekeeping are electronic watches with quartz movements. Expensive, collectible watches valued more for their workmanship and aesthetic appeal than for simple timekeeping, often have purely mechanical movements and are powered by springs, even though mechanical movements are less accurate than more affordable quartz movements. Before the inexpensive miniaturization that became possible in the 20th century, most watches were "pocket watches," which often had covers and were carried in a pocket and attached to a watch chain or watch fob. Watches evolved in the 1600s from spring powered clocks, which appeared in the 1400s. Movement. A movement in watchmaking is the mechanism that measures the passage of time and displays the current time (and possibly other information including date, month and day). Movements may be entirely mechanical, entirely electronic (potentially with no moving parts), or a blend of the two. Most watches intended mainly for timekeeping today have electronic movements, with mechanical hands on the face of the watch indicating the time. Mechanical movements. Compared to electronic movements, mechanical watches are less accurate, often with errors of seconds per day, and they are sensitive to position and temperature. As well, they are costly to produce, they require regular maintenance and adjustment, and they are more prone to failure. Nevertheless, the "old world" craftsmanship of mechanical watches still attracts interest from part of the watch-buying public. Mechanical movements use an escapement mechanism to control and limit the unwinding of the watch, converting what would otherwise be a simple unwinding, into a controlled and periodic energy release. Mechanical movements also use a balance wheel together with the balance spring (also known as Hairspring) to control motion of the gear system of the watch in a manner analogous to the pendulum of a pendulum clock. The tourbillon, an optional part for mechanical movements, is a rotating frame for the escapement which is used to cancel out or reduce the effects of bias to the timekeeping of gravitational origin. Due to the complexity designing a tourbillon, they are very expensive, and only found in "prestige" watches. The pin-lever (also called Roskopf movement after its inventor, Georges Frederic Roskopf), is a cheaper version of the fully levered movement which was manufactured in huge quantities by many Swiss manufacturers as well as Timex, until it was replaced by quartz movements. Tuning fork watches use a type of electromechanical movements. Introduced by Bulova in 1960, they use a tuning fork at a precise frequency (most often 360 hertz) to drive a mechanical watch. The task of converting electronically pulsed fork vibration into rotary movement is done via two tiny jeweled fingers, called pawls. Tuning fork watches were rendered obsolete when electronic quartz watches were developed, because quartz watches were cheaper to produce and even more accurate. Electronic movements. Electronic movements have few or no moving parts, as they use the piezoelectric effect in a tiny quartz crystal to provide a stable time base for a mostly electronic movement. The crystal forms a quartz oscillator which resonates at a specific and highly stable frequency, and which can be used to accurately pace a timekeeping mechanism. For this reason, electronic watches are often called "quartz watches." Most quartz movements are primarily electronic but are geared to drive mechanical hands on the face of the watch in order to provide a traditional analog display of the time, which is still preferred by most consumers. The first prototypes of electronic quartz watches were made by the CEH research laboratory in Switzerland in 1962. The first quartz watch to enter production was the Seiko 35 SQ Astron, which appeared in 1969. Modern quartz movements are produced in very large quantities, and even the cheapest wristwatches typically have quartz movements. Whereas mechanical movements can typically be off by several seconds a day, an inexpensive quartz movement in a child's wristwatch may still be accurate to within half a second per day—ten times better than a mechanical movement.Some watchmakers combine the quartz and mechanical movements, such as the Seiko Spring Drive, introduced in 2005. Radio time signal watches are a type of electronic quartz watches which synchronizes (time transfer) its time with an external time source such as an atomic clocks, time signals from GPS navigation satellites, the German DCF77 signal in Europe, WWVB in the US, and others. Movements of this type synchronize not only the time of day but also the date, the leap-year status of the current year, and the current state of daylight saving time (on or off). Power sources. Traditional mechanical watch movements use a spiral spring called a mainspring as a power source. In "manual watches" the spring must be rewound by the user periodically by turning the watch crown. Antique pocketwatches were wound by inserting a separate key into a hole in the back of the watch and turning it. Most modern watches are designed to run 40 hours on a winding, so must be wound daily, but some run for several days and a few have 192-hour mainsprings and are wound weekly. A "self-winding" or "automatic" mechanism is one that rewinds the mainspring of a mechanical movement by the natural motions of the wearer's body. The first self-winding mechanism, for pocketwatches, was invented in 1770 by Abraham-Louis Perrelet; but the first "self-winding," or "automatic," wristwatch was the invention of a British watch repairer named John Harwood in 1923. This type of watch allows for a constant winding without special action from the wearer: it works by an eccentric weight, called a winding rotor, which rotates with the movement of the wearer's wrist. The back-and-forth motion of the winding rotor couples to a ratchet to automatically wind the mainspring. Self winding watches usually can also be wound manually so they can be kept running when not worn, or if the wearer's wrist motions don't keep the watch wound. Some electronic watches are also powered by the movement of the wearer of the watch. Kinetic powered quartz watches make use of the motion of the wearer's arm turning a rotating weight, which turns a generator to supply power to charge a rechargeable battery that runs the watch. The concept is similar to that of self-winding spring movements, except that electrical power is generated instead of mechanical spring tension. Electronic watches require electricity as a power source. Some mechanical movements and hybrid electronic-mechanical movements also require electricity. Usually the electricity is provided by a replaceable battery. The first use of electrical power in watches was as substitute for the mainspring, in order to remove the need for winding. The first electrically-powered watch, the Hamilton Electric 500, was released in 1957 by the Hamilton Watch Company of Lancaster, Pennsylvania. Watch batteries (strictly speaking cells) are specially designed for their purpose. They are very small and provide tiny amounts of power continuously for very long periods (several years or more). In most cases, replacing the battery requires a trip to a watch-repair shop or watch dealer; this is especially true for watches that are designed to be water-resistant, as special tools and procedures are required to ensure that the watch remains water-resistant after battery replacement. Silver-oxide and lithium batteries are popular today; mercury batteries, formerly quite common, are no longer used, for environmental reasons. Cheap batteries may be alkaline, of the same size as silver-oxide but providing shorter life. Rechargeable batteries are used in some solar powered watches. Solar powered watches are powered by light. A photovoltaic cell on the face (dial) of the watch converts light to electricity, which in turn is used to charge a rechargeable battery or capacitor. The movement of the watch draws its power from the rechargeable battery or capacitor. As long as the watch is regularly exposed to fairly strong light (such as | The carrot'" ("Daucus carota" subsp. "sativus", Etymology: Middle French "carotte", from Late Latin "carōta", from Greek "karōton", originally from the Indoeuropean root "ker-" (horn), due to its horn-like shape) is a root vegetable, usually orange or white, or red-white blend in colour, with a crisp texture when fresh. The edible part of a carrot is a taproot. It is a domesticated form of the wild carrot "Daucus carota", native to Europe and southwestern Asia. It has been bred for its greatly enlarged and more palatable, less woody-textured edible taproot, but is still the same species. It is a biennial plant which grows a rosette of leaves in the spring and summer, while building up the stout taproot, which stores large amounts of sugars for the plant to flower in the second year. The flowering stem grows to about 1 metre (3 ft) tall, with an umbel of white flowers that produce a fruit called a mericarp by botanists, which is a type of schizocarp. Uses and nutrition. Carrots can be eaten in a variety of ways. The simplest way is raw as carrots are perfectly digestible without requiring cooking. Alternatively they may be chopped and boiled, fried or steamed, and cooked in soups and stews, as well as baby and pet foods. A well known dish is "carrots julienne". Grated carrots are used in carrot cakes, as well as carrot puddings, an old English dish thought to have originated in the early 1800s. The greens are edible as a leaf vegetable, but are rarely eaten by humans, as they are mildly toxic. Together with onion and celery, carrots are one of the primary vegetables used in a "mirepoix" to make various broths. Ever since the late 1980s, baby carrots or mini-carrots (carrots that have been peeled and cut into uniform cylinders) have been a popular ready-to-eat snack food available in many supermarkets. Carrot juice is also widely marketed, especially as a health drink, either stand-alone or blended with fruits and other vegetables. The carrot gets its characteristic and bright orange colour from β-carotene, which is metabolised into vitamin A in humans when bile salts are present in the intestines. Massive overconsumption of carrots can cause hypercarotenemia, a condition in which the skin turns orange (although hypercarotenemia is not itself dangerous unlike overdose of vitamin A, which can cause liver damage). Carrots are also rich in dietary fibre, antioxidants, and minerals. Lack of Vitamin A can cause poor vision, including night vision, and vision can be restored by adding Vitamin A back into the diet. The urban legend that says eating large amounts of carrots will allow one to see in the dark developed from stories of British gunners in World War II who were able to shoot down German planes in the darkness of night. The legend arose during the Battle of Britain when the RAF circulated a story about their pilots' carrot consumption as an attempt to cover up the discovery and effective use of radar technologies in engaging enemy planes. It reinforced existing German folklore and helped to encourage Britons—looking to improve their night vision during the blackouts—to grow and eat the vegetable. Ethnomedically, the roots are used to treat digestive problems, intestinal parasites, and tonsillitis or constipation. History. The wild ancestors of the carrot are likely to have come from Afghanistan, which remains the centre of diversity of "D. carota", the wild carrot. Selective breeding over the centuries of a naturally-occurring subspecies of the wild carrot, "Daucus carota" subsp. "sativus" reducing bitterness, increasing sweetness and minimizing the woody core, has produced the familiar garden vegetable. In early use, carrots were grown for their aromatic leaves and seeds, not their roots. Some relatives of the carrot are still grown for these, such as parsley, fennel, dill and cumin. The first mention of the root in classical sources is in the 1st century CE. The modern carrot appears to have been introduced to Europe in the 8-10th centuries; Ibn al-Awam, in Andalusia, describes both red and yellow carrots; Simeon Seth also mentions both colours in the 11th century. Orange-coloured carrots appeared in the Netherlands in the 17th century. These, the modern carrots, were intended by the antiquary John Aubrey (1626-1697) when he noted in his memoranda "Carrots were first sown at Beckington in Somersetshire Some very old Man there [in 1668] did remember their first bringing hither." In addition to wild carrot, these alternative (mostly historical) names are recorded for "Daucus carota": Bee's-nest, Bee's-nest plant, Bird's-nest, Bird's-nest plant, Bird's-nest root, Carota, Carotte (French), Carrot, Common carrot, Crow's-nest, Daucon, Dawke, Devil's-plague, Fiddle, Gallicam, Garden carrot, Gelbe Rübe (German), Gingidium, Hill-trot, Laceflower, Mirrot, Möhre (German), Parsnip (misapplied), Queen Anne's lace, Rantipole, Staphylinos, and Zanahoria. The parsnip is a close relative of the carrot, as is parsley. Cultivars. Carrot cultivars can be grouped into two broad classes, eastern carrots'" and "'western carrots'". More recently, a number of novelty cultivars have been bred for particular characteristics. The world's largest carrot was grown in Palmer, Alaska by John Evans in 1998, weighing 8.6 kg (19 lb). The city of Holtville, California promotes itself as "Carrot Capital of the World", and holds an annual festival devoted entirely to the carrot. Eastern carrots. Eastern carrots were domesticated in Central Asia, probably in modern-day Afghanistan in the 10th century, or possibly earlier. Specimens of the eastern carrot that survive to the present day are commonly purple or yellow, and often have branched roots. The purple colour common in these carrots comes from anthocyanin pigments. Western carrots. The western carrot emerged in the Netherlands in the 17th century, its orange colour making it popular in those countries as an emblem of the House of Orange and the struggle for Dutch independence. The orange colour results from abundant carotenes in these cultivars. While orange carrots are the norm in the West, other colours do exist, including white, yellow, red, and purple. These other colours of carrot are raised primarily as novelty crops. The Vegetable Improvement Center at Texas A&M University has developed a purple-skinned, orange-fleshed carrot, the "BetaSweet" (also known as the Maroon Carrot), with substances to prevent cancer, which has recently entered very limited commercial distribution, through J&D Produce of Edinburg TX. This variety of carrot is also known to be high in β-carotene which is an essential nutrient. The high concentrations of this nutrient give the carrot its maroon shade. Western carrot cultivars are commonly classified by their root shape: While any carrot can be harvested before reaching its full size as a more tender "baby" carrot, some fast-maturing cultivars have been bred to produce smaller roots. The most extreme examples produce round roots about 2.5 centimetres (1 in) in diameter. These small cultivars are also more tolerant of heavy or stony soil than long-rooted cultivars such as 'Nantes' or 'Imperator'. The "baby carrots" sold ready-to-eat in supermarkets are, however, often not from a smaller cultivar of carrot, but are simply full-sized carrots that have been sliced and peeled to make carrot sticks of a uniform shape and size. Carrot flowers are pollinated primarily by bees. Seed growers use honeybees or mason bees for their pollination needs. Carrots are used as food plants by the larvae of some Lepidoptera species, including Common Swift, Garden Dart, Ghost Moth, Large Yellow Underwing and Setaceous Hebrew Character. Novelty carrots. Food enthusiasts and researchers have developed other varieties of carrots through traditional breeding methods. Novelty carrots are also grown throughout Western Europe in flower pots and are noted for their distinctly minty flavour. One particular variety lacks the usual orange pigment from carotenes, owing its white colour to a recessive gene for tocopherol (Vitamin E). Derived from "Daucus carota" L. and patented (US patent #6,437,222) at the University of Wisconsin-Madison, the variety is intended to supplement the dietary intake of Vitamin E. Production trends. In 2005, China was the largest producer of carrots and turnips, according to the FAO. China accounted for at least one third of the global output, followed by Russia and the United States. In 2005, a poll of 2,000 people revealed that the carrot was Britain's third favourite culinary vegetable. |