query: Where can black wildebeest be found?

title: Black wildebeest

text: The natural populations of black wildebeest, endemic to the southern part of Africa, were almost completely exterminated in the 19th century, due to their reputation as pests and the value of their hides and meat. However, the species has been reintroduced widely from captive specimens, both in private areas and nature reserves throughout most of Lesotho, Swaziland, and South Africa. It has also been introduced outside its natural range in Namibia and Kenya.

title: Black wildebeest

text: However, black wildebeest can also affect human beings negatively. Wild individuals can be competitors of commercial livestock, and can transmit fatal diseases such as rinderpest, and cause epidemics among animals, particularly domestic cattle. They can also spread ticks, lungworms, tapeworms, flies, and paramphistome flukes.[6]

title: Blue wildebeest

text: This species of wildebeest seems to have evolved around 2.5 million years ago. The black wildebeest is believed to have diverged from the blue wildebeest to become a distinct species around a million years ago, in the mid- to late Pleistocene. Fossil evidence suggests that blue wildebeest were quite common in the Cradle of Humankind in the past. Apart from eastern Africa, fossils are commonly found in Elandsfontein, Cornelia, and Florisbad.

title: Blue wildebeest

text: In terms of skull length, the smallest subspecies of the blue wildebeest is the western white-bearded wildebeest. It is also the darkest subspecies; the eastern white-bearded wildebeest is the lightest race. Both subspecies possess a creamy white beard, whereas the beard is black in both the Nyassaland wildebeest and the common wildebeest. The longest muzzles are found in the Nyassaland wildebeest, and the shortest in female western white-bearded wildebeest.

title: Wildebeest

text: Blue wildebeest fossils dating back some 2.5 million years ago are common and widespread. They have been found in the fossil-bearing caves at the Cradle of Humankind north of Johannesburg. Elsewhere in South Africa, they are plentiful at such sites as Elandsfontein, Cornelia, and Florisbad.[17] The earliest fossils of the black wildebeest were found in sedimentary rock in Cornelia in the Orange Free State and dated back about 800,000 years.[16] Today, five subspecies of the blue wildebeest are recognized, while the black wildebeest has no named subspecies.[18][19]

title: Black wildebeest

text: The black wildebeest is currently included in the same genus as the blue wildebeest (Connochaetes taurinus). This has not always been the case, and at one time the latter was placed under a separate genus of its own, Gorgon.[7] The black wildebeest lineage seems to have diverged from the blue wildebeest in the mid- to late Pleistocene, and became a distinct species around a million years ago.[8] This evolution is quite recent on a geologic time scale.[9]

title: Black wildebeest

text: The black wildebeest is native to southern Africa. Its historical range included South Africa, Swaziland, and Lesotho, but in the latter two countries, it was hunted to extinction in the 19th century. It has now been reintroduced to them and also introduced to Namibia, where it has become well established.[1]

title: Black wildebeest

text: Where it lives alongside the blue wildebeest, the two species can hybridise, and this is regarded as a potential threat to the maintenance of the species.[1][11] The black wildebeest was once very numerous and was present in Southern Africa in vast herds, but by the end of the 19th century, it had nearly been hunted to extinction and fewer than 600 animals remained.[15] A small number of individuals was still present in game reserves and at zoos, and from these, the population was rescued.[1]

title: Black wildebeest

text: Features necessary for defending a territory, such as the horns and broad-based skull of the modern black wildebeest, have been found in their fossil ancestors.[8] The earliest known fossil remains are in sedimentary rock in Cornelia in the Orange Free State and date back about 800,000 years.[10] Fossils have also been reported from the Vaal River deposits, though whether or not they are as ancient as those found in Cornelia is unclear. Horns of the black wildebeest have been found in sand dunes near Hermanus in South Africa. This is far beyond the recorded range of the species and it has been suggested that these animals may have migrated to that region from the Karoo.[2]

title: Black wildebeest

text: Black wildebeest are mainly active during the early morning and late afternoon, preferring to rest during the hottest part of the day.[26] The animals can run at speeds of 80km/h (50mph).[26] When a person approaches a herd to within a few hundred metres, the wildebeest snort and run a short distance before stopping and looking back, repeating this behaviour if further approached. They communicate with each other using pheromones detected by flehmen and several forms of vocal communication. One of these is a metallic snort or an echoing "hick", that can be heard up to 1.5 km (1 mi) away.[27] They are preyed on by the lion, spotted hyena, Cape hunting dog, leopard, cheetah, and crocodile. Of these, the calves are targeted mainly by the hyenas, while lions attack the adults.[2]

title: Alcelaphine gammaherpesvirus 2

text: All species of African wildebeest and hartbeest can be infected or at least carry this virus. There is no direct evidence that other African wild variants like addax can be hosts, but research is ongoing. The alcelaphine antelope affecting form is primarily found in Africa, in the natural habitat of wildebeest, hartebeest, and topi. It has also occurred in zoos and wild animal parks that also kept wildebeest. The increasing popularity in North America of wild animal parks may spread its range further.

title: Black wildebeest

text: The black wildebeest or white-tailed gnu (Connochaetes gnou) is one of the two closely related wildebeest species. It is a member of the genus Connochaetes and family Bovidae. It was first described in 1780 by Eberhard August Wilhelm von Zimmermann. The black wildebeest is typically 170–220cm (67–87in) in head-and-body length, and the typical weight is 110–180kg (240–400lb). Males stand about 111–121cm (44–48in) at the shoulder, while the height of the females is 106–116cm (42–46in). The black wildebeest is characterised by its white, long, horse-like tail. It also has a dark brown to black coat and long, dark-coloured hair between its forelegs and under its belly.

title: Wildebeest

text: The black wildebeest is depicted on the coat of arms of the Province of Natal in South Africa. Over the years, the South African authorities have issued several stamps displaying the animal and the South African Mint has struck a two cent piece with a prancing black wildebeest.[57]

title: Wildebeest

text: The blue wildebeest is native to eastern and southern Africa. Its range includes Kenya, Tanzania, Botswana, Zambia, Zimbabwe, Mozambique, South Africa, Swaziland and Angola.[34] It is no longer found in Malawi but has been successfully reintroduced into Namibia. Blue wildebeest are mainly found in short grass plains bordering bush-covered acacia savannas, thriving in areas that are neither too wet nor too dry. They can be found in habitats that vary from overgrazed areas with dense bush to open woodland floodplains.[32] In East Africa, the blue wildebeest is the most abundant big game species, both in population and biomass.[25] It is a notable feature of the Serengeti National Park in Tanzania, the Maasai Mara National Reserve in Kenya and the Liuwa Plain National Park in Zambia.[29]

title: Black wildebeest

text: The black wildebeest is known to hybridise with its taxonomically close relative, the blue wildebeest. Male black wildebeest have been reported to mate with female blue wildebeest and vice versa.[11] The differences in social behaviour and habitats have historically prevented interspecific hybridisation between the species, but hybridisation may occur when they are both confined within the same area. The resulting offspring is usually fertile. A study of these hybrid animals at Spioenkop Dam Nature Reserve in South Africa revealed that many had disadvantageous abnormalities relating to their teeth, horns, and the wormian bones in the skull.[12] Another study reported an increase in the size of the hybrid as compared to either of its parents. In some animals, the auditory bullae are highly deformed, and in others, the radius and ulna are fused.[13]

title: Black wildebeest

text: Though they are not present in their natural habitat in such large numbers today, black wildebeest were at one time the main herbivores in the ecosystem and a main prey item for large predators such as the lion. Now, they are economically important for human beings, as they are a major tourist attraction, as well as providing animal products such as leather and meat. The hide makes good quality leather and the flesh is coarse, dry and rather hard.[26] Wildebeest meat is dried to make biltong, an important part of South African cuisine. The meat of females is more tender than that of males, and is at its best during the autumn season.[35] The wildebeest can provide 10 times as much meat as Thomson's gazelle.[36] The silky, flowing tail is used to make fly-whisks or chowries.[26]

title: Black wildebeest

text: More than 18,000 individuals are now believed to remain, 7,000 of which are in Namibia, outside their natural range, and where they are farmed. Around 80% of the wildebeest occurs in private areas, while the other 20% is confined in protected areas. The population is now trending upward (particularly on private land) and for this reason the International Union for Conservation of Nature (IUCN), in its Red List of Threatened Species, rates the black wildebeest as being of "Least Concern". Its introduction into Namibia has been a success and numbers have increased substantially there from 150 in 1982 to 7,000 in 1992.[1][14]

title: Wildebeest

text: In the early 20th century, one species of the wildebeest, C. albojubatus, was identified in eastern Africa. In 1914, two separate races of the wildebeest were introduced, namely Gorgon a. albojubatus ("Athi white-bearded wildebeest") and G. a. mearnsi ("Loita white-bearded wildebeest"). However, in 1939, the two were once again merged into a single race, Connochaetes taurinus albojubatus. In the mid-20th century, two separate forms were recognised, Gorgon taurinus hecki and G. t. albojubatus.[12] Finally, two distinct types of wildebeest – the blue and black wildebeest – were identified. The blue wildebeest was at first placed under a separate genus, Gorgon,[13][14] while the black wildebeest belonged to the genus Connochaetes. Today, they are united in the single genus Connochaetes, with the black wildebeest being named (C. gnou) and the blue wildebeest (C. taurinus).[10]

title: Blue wildebeest

text: The blue wildebeest ("Connochaetes taurinus"), also called the common wildebeest, white-bearded wildebeest, or brindled gnu, is a large antelope and one of the two species of wildebeests. It is placed in the genus "Connochaetes" and family Bovidae, and has a close taxonomic relationship with the black wildebeest. The blue wildebeest is known to have five subspecies. This broad-shouldered antelope has a muscular, front-heavy appearance, with a distinctive, robust muzzle. Young blue wildebeest are born tawny brown, and begin to take on their adult colouration at the age of 2 months. The adults' hues range from a deep slate or bluish gray to light gray or even grayish brown. Both sexes possess a pair of large curved horns.

title: Wildebeest

text: Aerial photography has revealed that a level of organisation occurs in the movement of the herd that cannot be apparent to each individual animal; for example, the migratory herd exhibits a wavy front, and this suggests that some degree of local decision-making is taking place.[41] Numerous documentaries feature wildebeest crossing rivers, with many being eaten by crocodiles or drowning in the attempt. While having the appearance of a frenzy, recent research has shown a herd of wildebeest possesses what is known as a "swarm intelligence", whereby the animals systematically explore and overcome the obstacle as one.[42] Major predators that feed on wildebeest include the lion, hyena, cheetah, leopard, and crocodile, which seem to favour the wildebeest over other prey.[29] Wildebeest, however, are very strong, and can inflict considerable injury even to a lion. Wildebeest have a maximum running speed of around 80km/h (50mph).[43][44] The primary defensive tactic is herding, where the young animals are protected by the older, larger ones, while the herd runs as a group. Typically, the predators attempt to cut out a young or ill animal and attack without having to worry about the herd. Wildebeest have developed additional sophisticated cooperative behaviours, such as animals taking turns sleeping while others stand guard against a night attack by invading predators. Wildebeest migrations are closely followed by vultures, as wildebeest carcasses are an important source of food for these scavengers. The vultures consume about 70% of the wildebeest carcasses available. Decreases in the number of migrating wildebeest have also had a negative effect on the vultures.[45] In the Serengeti ecosystem, Tanzania, wildebeest may help facilitate the migration of other, smaller-bodied grazers, such as Thomson's gazelles (Eudorcas thomsonii), which eat the new-growth grasses stimulated by wildebeest foraging.[46]

title: Wildebeest

text: Both species of wildebeest are even-toed, horned, greyish-brown ungulates resembling cattle. Males are larger than females and both have heavy forequarters compared to their hindquarters. They have broad muzzles, Roman noses, and shaggy manes and tails.[25] The most striking morphological differences between the black and blue wildebeest are the orientation and curvature of their horns and the color of their coats. The blue wildebeest is the bigger of the two species. In males, blue wildebeest stand 150cm tall at the shoulder and weigh around 250kg, while the black wildebeest stands 111 to 120cm tall[26] and weighs about 180kg. In females, blue wildebeest have a shoulder height of 135cm and weigh 180kg while black wildebeest females stand 108cm at the shoulder and weigh 155kg. The horns of blue wildebeest protrude to the side, then curve downwards before curving up back towards the skull, while the horns of the black wildebeest curve forward then downward before curving upwards at the tips. Blue wildebeest tend to be a dark grey color with stripes, but may have a bluish sheen. The black wildebeest has brown-coloured hair, with a mane that ranges in color from cream to black, and a cream-coloured tail. The blue wildebeest lives in a wide variety of habitats, including woodlands and grasslands, while the black wildebeest tends to reside exclusively in open grassland areas.[18] In some areas, the blue wildebeest migrates over long distances in the winter, whereas the black wildebeest does not.[27] The milk of the female black wildebeest contains a higher protein, lower fat, and lower lactose content than the milk of the blue wildebeest.[28] Wildebeest can live more than 40 years, though their average lifespan is around 20 years.[29]

title: Blue wildebeest

text: The blue wildebeest is a herbivore, feeding primarily on short grasses. It forms herds which move about in loose aggregations, the animals being fast runners and extremely wary. The mating season begins at the end of the rainy season and a single calf is usually born after a gestational period of about 8.5 months. The calf remains with its mother for 8 months, after which it joins a juvenile herd. Blue wildebeest are found in short-grass plains bordering bush-covered acacia savannas in southern and eastern Africa, thriving in areas that are neither too wet nor too arid. Three African populations of blue wildebeest take part in a long-distance migration, timed to coincide with the annual pattern of rainfall and grass growth on the volcanic soil short-grass plains where they can find the nutrient-rich forage necessary for lactation and calf growth.

title: Black wildebeest

text: The black wildebeest is a herbivore, and almost the whole diet consists of grasses. Water is an essential requirement. The three distinct social groups are the female herds, the bachelor herds, and the territorial bulls. They are fast runners, and communicate using a variety of visual and vocal communications. The primary breeding season for the black wildebeest is from February to April. A single calf is usually born after a gestational period of about 8.5 months. The calf remains with its mother until her next calf is born a year later. The black wildebeest inhabits open plains, grasslands, and Karoo shrublands.

title: Black wildebeest

text: The black wildebeest is depicted on the coat of arms of the Province of Natal in South Africa. Over the years, the South African authorities have issued stamps displaying the animal and the South African Mint has struck a 5-rand coin with a prancing black wildebeest.[2][34]

title: Black wildebeest

text: Before the arrival of Europeans in the area, wildebeest roamed widely, probably in relation to the arrival of the rains and the availability of good forage. They never made such extensive migrations as the blue wildebeest, but at one time, they crossed the Drakensberg Range, moving eastwards in autumn, searching for good pastures. Then they returned to the highvelds in the spring and moved towards the west, where sweet potato and Karoo vegetation were abundant. They also moved from north to south as the sourgrass found north of the Vaal River matured and became unpalatable, the wildebeest only consuming young shoots of sourgrass.[2] Now, almost all black wildebeest are in reserves or on farms, and the extent of their movements is limited.[1]

title: Wildebeest

text: Wildebeests, also called gnus, are antelopes in the genus Connochaetes. They belong to the family Bovidae, which includes antelopes, cattle, goats, sheep, and other even-toed horned ungulates. Connochaetes includes two species, both native to Africa: the black wildebeest or white-tailed gnu (C. gnou), and the blue wildebeest or brindled gnu (C. taurinus). Fossil records suggest these two species diverged about one million years ago, resulting in a northern and a southern species. The blue wildebeest remained in its original range and changed very little from the ancestral species, while the black wildebeest changed more as adaptation to its open grassland habitat in the south. The most obvious way of telling the two species apart are the differences in their colouring and in the way their horns are oriented.

title: Wildebeest

text: Today, many wildebeest populations are experiencing rapid declines. Overland migration as a biological process requires large, connected landscapes, which are increasingly difficult to maintain, particularly over the long term, when human demands on the landscape compete. The most acute threat comes from migration barriers, such as fences and roads. In one of the more striking examples of the consequences of fence-building on terrestrial migrations, Botswanan authorities placed thousands of kilometres of fences across the Kalahari that prevented wildebeests from reaching watering holes and grazing grounds, resulting in the deaths of tens of thousands of individuals, reducing the wildebeest population to less than 10% of its previous size.[54] Illegal hunting is a major conservation concern in many areas, along with natural threats posed by main predators (which include lions, leopards, African hunting dogs, cheetahs and hyenas). Where the black and blue wildebeest share a common range, the two can hybridise, and this is regarded as a potential threat to the black wildebeest.[22]

title: Blue wildebeest

text: Blue wildebeest are mainly found in short-grass plains bordering bush-covered acacia savannas in southern and eastern Africa, thriving in areas that are neither too wet nor too arid. They can be found in habitats that vary from overgrazed areas with dense bush to open woodland floodplains. Trees such as "Brachystegia" and "Combretum" spp. are common in these areas. Blue wildebeest can tolerate arid regions as long as a potable water supply is available, normally within about distance. The southern limit of the blue wildebeest stops at the Orange River, while the western limit is bounded by Lake Victoria and Mount Kenya. The range does not include montane or temperate grasslands. These wildebeest are rarely found at altitudes over . With the exception of a small population of Cookson's wildebeest that occurs in the Luangwa Valley (Zambia), the wildebeest is absent in the wetter parts of the southern savanna country, and particularly is not present in miombo woodlands.

title: Blue wildebeest

text: The blue wildebeest is a herbivore, feeding primarily on the short grasses which commonly grow on light, and alkaline soils that are found in savanna grasslands and on plains. The animal's broad mouth is adapted for eating large quantities of short grass and it feeds both during the day and night. When grass is scarce, it will also eat the foliage of shrubs and trees. Wildebeest commonly associate with plains zebras as the latter eat the upper, less nutritious grass canopy, exposing the lower, greener material which the wildebeest prefer. Whenever possible, the wildebeest likes to drink twice daily and due to its regular requirement for water, it usually inhabits moist grasslands and areas with available water sources. The blue wildebeest drinks 9 to 12 litres of water every one to two days. Despite this, it can also survive in the arid Kalahari desert, where it obtains sufficient water from melons and water-storing roots and tubers.

title: Black wildebeest

text: Black wildebeest act as hosts to a number of external and internal parasites. A study of the animal in Karroid Mountainveld (Eastern Cape Province, South Africa) revealed the presence of all the larval stages of the nasal bot flies Oestrus variolosus and Gedoelstia hässleri. The first instar larvae of G. hässleri were found in large numbers on the dura mater of wildebeest calves, specially between June and August, and these later migrated to the nasal passages.[24] Repeated outbreaks of mange (scab) have led to large-scale extinctions.[2] The first study of the protozoa in blue and black wildebeest showed the presence of 23 protozoan species in the rumen, with Diplodinium bubalidis and Ostracodinium damaliscus common in all the animals.[25]

title: Black wildebeest

text: The black wildebeest is particularly susceptible to anthrax, and rare and widely scattered outbreaks have been recorded and have proved deadly.[21] Ataxia related to myelopathy and low copper concentrations in the liver have also been seen in the black wildebeest.[22] Heartwater (Ehrlichia ruminantium) is a tick-borne rickettsial disease that affects the black wildebeest, and as the blue wildebeest is fatally affected by rinderpest and foot-and-mouth disease, it is also likely to be susceptible to these. Malignant catarrhal fever is a fatal disease of domestic cattle caused by a gammaherpesvirus. Like the blue wildebeest, the black wildebeest seems to act as a reservoir for the virus and all animals are carriers, being persistently infected, but showing no symptoms. The virus is transmitted from mother to calf during the gestation period or soon after birth.[23]


query: What is a magnetic field?

title: Magnetic field

text: A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials. In everyday life, the effects of magnetic fields are often seen in permanent magnets, which pull on magnetic materials (such as iron) and attract or repel other magnets. Magnetic fields surround and are created by magnetized material and by moving electric charges (electric currents) such as those used in electromagnets. Magnetic fields exert forces on nearby moving electrical charges and torques on nearby magnets. In addition, a magnetic field that varies with location exerts a force on magnetic materials. Both the strength and direction of a magnetic field varies with location. As such, it is an example of a vector field.

title: Friction-plate electromagnetic couplings

text:
A horseshoe magnet (A-1) has a north and south pole. If a piece of carbon steel contacts both poles, a magnetic circuit is created. In an electromagnetic coupling, the north and south pole is created by a coil shell and a wound coil.
In a clutch, (B1) when power is applied, a magnetic field is created in the coil (A2 blue). This field (flux) overcomes an air gap between the clutch rotor (A2 yellow) and the armature (A2 red). This magnetic attraction, pulls the armature in contact with the rotor face. The frictional contact, which is being controlled by the strength of the magnetic field, is what causes the rotational motion to start.

title: Flux pinning

text: Flux pinning is the phenomenon where a superconductor is pinned in space above a magnet. The superconductor must be a type-II superconductor because type-I superconductors cannot be penetrated by magnetic fields. The act of magnetic penetration is what makes flux pinning possible. At higher magnetic fields (above Hc1 and below Hc2) the superconductor allows magnetic flux to enter in quantized packets surrounded by a superconducting current vortex (see Quantum vortex). These sites of penetration are known as flux tubes. The number of flux tubes per unit area is proportional to the magnetic field with a constant of proportionality equal to the magnetic flux quantum. On a simple 76 millimeter diameter, 1-micrometer thick disk, next to a magnetic field of 28 kA/m, there are approximately 100 billion flux tubes that hold 70,000 times the superconductor's weight. At lower temperatures the flux tubes are pinned in place and cannot move. This pinning is what holds the superconductor in place thereby allowing it to levitate. This phenomenon is closely related to the Meissner effect, though with one crucial difference — the Meissner effect shields the superconductor from all magnetic fields causing repulsion, unlike the pinned state of the superconductor disk which pins flux, and the superconductor in place.

title: Magnet

text: A magnet both produces its own magnetic field and responds to magnetic fields. The strength of the magnetic field it produces is at any given point proportional to the magnitude of its magnetic moment. In addition, when the magnet is put into an external magnetic field, produced by a different source, it is subject to a torque tending to orient the magnetic moment parallel to the field.[10] The amount of this torque is proportional both to the magnetic moment and the external field. A magnet may also be subject to a force driving it in one direction or another, according to the positions and orientations of the magnet and source. If the field is uniform in space, the magnet is subject to no net force, although it is subject to a torque.[11]

title: Faraday paradox

text: Note that v does not represent the velocity that magnetic fields lines travel through the conductor. The magnetic field pattern observed depends on the frame of reference. They have no velocity on their own. To illustrate, imagine that one were to take a magnet and flip it 180 degrees. The result of assuming that these field lines actually have velocity of their own would be that magnetic field lines far away would swing to the other side, potentially faster than the speed of light, however, that is not what happens.

title: Magnetic domain

text: However, the domains can also exist in other configurations in which their magnetization mostly points in the same direction, creating an external magnetic field. Although these are not minimum energy configurations, due to a phenomenon where the domain walls become "pinned" to defects in the crystal lattice they can be "local" minimums of the energy, and therefore can be very stable. Applying an external magnetic field to the material can make the domain walls move, causing the domains aligned with the field to grow, and the opposing domains to shrink. When the external field is removed, the domain walls remain pinned in their new orientation and the aligned domains produce a magnetic field. This is what happens when a piece of ferromagnetic material is "magnetized" and becomes a permanent magnet.

title: Magnetism

text:
All observations on electromagnetism apply to what might be considered to be primarily magnetism, e.g. perturbations in the magnetic field are necessarily accompanied by a nonzero electric field, and propagate at the speed of light.
In a vacuum,
where is the vacuum permeability.

title: Preclinical imaging

text: Principle: Magnetic Resonance Imaging (MRI) exploits the nuclear magnetic alignments of different atoms inside a magnetic field to generate images. MRI machines consist of large magnets that generate magnetic fields around the target of analysis. These magnetic fields cause paramagnetic atoms such as hydrogen, gadolinium, and manganese to align themselves in a magnetic dipole along the magnetic fields, created by the radiofrequency (RF) coils inside the MRI machine. What the machine captures from the subject is the relaxation of the atoms as they return to their normal alignment when the RF pulse is temporarily ceased. With this data, a computer will generate an image of the subject based on the resonance characteristics of different tissue types.

title: DC motor

text: The sequence of turning a particular coil on or off dictates what direction the effective electromagnetic fields are pointed. By turning on and off coils in sequence a rotating magnetic field can be created. These rotating magnetic fields interact with the magnetic fields of the magnets (permanent or electromagnets) in the stationary part of the motor (stator) to create a torque on the armature which causes it to rotate. In some DC motor designs the stator fields use electromagnets to create their magnetic fields which allow greater control over the motor.

title: Electromagnetic propulsion

text: Electromagnetic propulsion (EMP), is the principle of accelerating an object by the utilization of a flowing electrical current and magnetic fields. The electrical current is used to either create an opposing magnetic field, or to charge a field, which can then be repelled. When a current flows through a conductor in a magnetic field, an electromagnetic force known as a Lorentz force, pushes the conductor in a direction perpendicular to the conductor and the magnetic field. This repulsing force is what causes propulsion in a system designed to take advantage of the phenomenon. The term electromagnetic propulsion (EMP) can be described by its individual components: electromagneticusing electricity to create a magnetic field, and propulsionthe process of propelling something. When a fluid (liquid or gas) is employed as the moving conductor, the propulsion may be termed magnetohydrodynamic drive. One key difference between EMP and propulsion achieved by electric motors is that the electrical energy used for EMP is not used to produce rotational energy for motion; though both use magnetic fields and a flowing electrical current.

title: Magnetic field

text: In 1831, Michael Faraday discovered electromagnetic induction when he found that a changing magnetic field generates an encircling electric field. He described this phenomenon in what is known as Faraday's law of induction. Later, Franz Ernst Neumann proved that, for a moving conductor in a magnetic field, induction is a consequence of Ampère's force law.[9] In the process, he introduced the magnetic vector potential, which was later shown to be equivalent to the underlying mechanism proposed by Faraday.

title: Exchange spring magnet

text: The magnetostatic energy is the energy stored in the field generated by a material's magnetic moments. The magnet's field reaches its maximum intensity if all the magnetic moments orient in one direction; this is what occurs in a hard magnet. In order to prevent building up the magnetic field, sometimes magnetic moments tend to form loops. That way, the energy stored in the magnetic field can be constrained; this is what occurs in a soft magnet. What determines whether a magnet is hard or soft is the dominant term of its magnetic energy. For hard magnets, the anisotropy constant is relatively large, making the magnetic moments align with easy axis. The opposite case applies to soft magnets, in which the magnetostatic energy is dominant.

title: Bean's critical state model

text: To understand the origin of the irreversible magnetization: assume a hollow cylinder in an external magnetic field parallel to the cylinder axis. In the Meissner phase, a screening current is within the London penetration depth. Exceeding "H", vortices start to penetrate into the superconductor. These vortices are pinned on the surface (Bean–Livingston barrier). In the area below the surface, which is penetrated by the vortices, is a current with the density "J". At low fields "(H < H)", the vortices do not reach the inner surface of the hollow cylinder and the interior stays field-free. For "H > H", the vortices penetrate the whole cylinder and a magnetic field appears in the interior, which then increases with increasing external field. Let us now consider what happens, if the external field is then decreased: Due to induction, an opposed critical current is generated at the outer surface of the cylinder keeping inside the magnetic field for "H < H < H" constant. For "H > H," the opposed critical current penetrates the whole cylinder and the inner magnetic field starts to decrease with decreasing external field. When the external field vanishes, a remnant internal magnetic field occurs (comparable to the remanent magnetization of a ferromagnet). With an opposed external field "H," the internal magnetic field finally reaches 0T ("H" equates the coercive field of a ferromagnet).

title: Magnetic field

text: An azimuthal magnetic field is one that runs east–west. A meridional magnetic field is one that runs north–south. In the solar dynamo model of the Sun, differential rotation of the solar plasma causes the meridional magnetic field to stretch into an azimuthal magnetic field, a process called the omega-effect. The reverse process is called the alpha-effect.[47] A dipole magnetic field is one seen around a bar magnet or around a charged elementary particle with nonzero spin. A quadrupole magnetic field is one seen, for example, between the poles of four bar magnets. The field strength grows linearly with the radial distance from its longitudinal axis. A solenoidal magnetic field is similar to a dipole magnetic field, except that a solid bar magnet is replaced by a hollow electromagnetic coil magnet. A toroidal magnetic field occurs in a doughnut-shaped coil, the electric current spiraling around the tube-like surface, and is found, for example, in a tokamak. A poloidal magnetic field is generated by a current flowing in a ring, and is found, for example, in a tokamak. A radial magnetic field is one in which field lines are directed from the center outwards, similar to the spokes in a bicycle wheel. An example can be found in a loudspeaker transducers (driver).[48] A helical magnetic field is corkscrew-shaped, and sometimes seen in space plasmas such as the Orion Molecular Cloud.[49]

title: Coronal mass ejection

text: On the Sun, magnetic reconnection may happen on solar arcades—a series of closely occurring loops of magnetic lines of force. These lines of force quickly reconnect into a low arcade of loops, leaving a helix of magnetic field unconnected to the rest of the arcade. The sudden release of energy during this process causes the solar flare and ejects the CME. The helical magnetic field and the material that it contains may violently expand outwards forming a CME. This also explains why CMEs and solar flares typically erupt from what are known as the active regions on the Sun where magnetic fields are much stronger on average.

title: Steorn

text: No specific details of the workings of the claimed technology were made public. McCarthy stated in a 2006 RTÉ radio interview, "What we have developed is a way to construct magnetic fields so that when you travel round the magnetic fields, starting and stopping at the same position, you have gained energy". In 2011, Steorn's website was updated to suggest that the Orbo is based on magnetic fields which vary over time. Barry Williams of the Australian Skeptics has pointed out that Steorn is "not the first company to claim they have suddenly discovered the miraculous property of magnetism that allows you to get free energy" while Martin Fleischmann says that it is not credible that positioning of magnetic fields could create energy.

title: Alfvén's theorem

text: The flux freezing indicates that the magnetic field topology cannot change in a perfectly conducting fluid. However, this would lead to highly tangled magnetic fields with very complicated topologies that should impede the fluid motions. Nevertheless, astrophysical plasmas with high electrical conductivities do not generally show such complicated tangled fields. Also magnetic reconnection seems to occur in these plasmas unlike what is expected from the flux freezing conditions. This has important implications for magnetic dynamos. In fact, a very high electrical conductivity translates into high magnetic Reynolds numbers, which indicates that the plasma will be turbulent.

title: Curie's law

text:
This is magnetization of one particle, the total magnetization of the solid is given by
formula_17
where "n" is the number density of magnetic moments. The formula above is known as the Langevin paramagnetic equation.
Pierre Curie found an approximation to this law which applies to the relatively high temperatures and low magnetic fields used in his experiments. Let's see what happens to the magnetization as we specialize it to large formula_4 and small formula_19. As temperature increases and magnetic field decreases, the argument of hyperbolic tangent decreases. Another way to say this is

title: Faraday paradox

text: Instead, what happens is that rotating a magnet causes subatomic particles in the magnet to acquire a change in velocity. However, in the rotated magnet, the velocities of electrons would vary ahead or behind those of the other particles, due to their lower mass compared to nuclei. There is length contraction of fields propagating from moving charges, and the length contraction of the electric fields E of the electrons would be greater or lesser than the contraction of the E fields of the positive nuclei depending on whether the rotation of the magnet was aligned to, or opposed to, the electron spins which give rise to the magnetism.

title: Geomagnetic excursion

text: Scientific opinion is divided on what causes geomagnetic excursions. The dominant theory is that they are an inherent aspect of the dynamo processes that maintain the Earth's magnetic field. In computer simulations, it is observed that magnetic field lines can sometimes become tangled and disorganized through the chaotic motions of liquid metal in the Earth's core. In such cases, this spontaneous disorganization can cause decreases in the magnetic field as perceived at the Earth's surface. In truth, under this scenario, the Earth's magnetic field intensity does not significantly change in the core itself, but rather energy is transferred from a dipole configuration to higher order multipole moments which decay more rapidly with the distance from the Earth's core, so that the expression of such a magnetic field at the surface of the Earth would be considerably less, even without significant changes in the strength of the deep field. This scenario is supported by observed tangling and spontaneous disorganizations in the solar magnetic field. However, this process in the sun invariably leads to a reversal of the solar magnetic field (see: solar cycle), and has never been observed such that the field would recover without large scale changes in field orientation.

title: Curie temperature

text: A material is paramagnetic only above its Curie temperature. Paramagnetic materials are non-magnetic when a magnetic field is absent and magnetic when a magnetic field is applied. When a magnetic field is absent, the material has disordered magnetic moments; that is, the atoms are asymmetrical and not aligned. When a magnetic field is present, the magnetic moments are temporarily realigned parallel to the applied field; the atoms are symmetrical and aligned. The magnetic moments being aligned in the same direction are what causes an induced magnetic field.

title: RuBee

text: IEEE 1902.1 RuBee uses magnetic waves also often called inductive communication. James Clerk Maxwell presented his now famous set of equations (Maxwell's Equations) to the Royal Society in 1864. These equations describe what happens when an electron travels along a conductive wire. Two fields are created, the Electric Field, labeled E, and the Magnetic Field, labeled H. These electric and magnetic fields travel through the aether, (i.e. outer space or the far field), at the speed of light with an assumed impedance of 377 Ω. E, the electric field, may be given in newtons per coulomb or volts per meter, and H, the magnetic field, may be given in gauss or amperes per meter. The two fields are tied together with the aether to form simple electric circuit capable of transferring power. However, when these two fields are measured in what is called the near field (much less than the wavelength of the signal) very strange things happen. (Also see Capps “Near Field or Far Field"). E and H are no longer connected in a simple predictable manner. The value of "c" (speed of light) and the resistance of the aether are altered and it is possible to produce large H values with low E values. It is as if the aether impedance has been reduced to only a few ohms.

title: Magnetic flux

text:
The magnetic interaction is described in terms of a vector field, where each point in space (and time) is associated with a vector that determines what force a moving charge would experience at that point (see Lorentz force). Since a vector field is quite difficult to visualize at first, in elementary physics one may instead visualize this field with field lines. The magnetic flux through some surface, in this simplified picture, is proportional to the number of field lines passing through that surface (in some contexts, the flux may be defined to be precisely the number of field lines passing through that surface; although technically misleading, this distinction is not important). Note that the magnetic flux is the "net" number of field lines passing through that surface; that is, the number passing through in one direction minus the number passing through in the other direction (see below for deciding in which direction the field lines carry a positive sign and in which they carry a negative sign).
In more advanced physics, the field line analogy is dropped and the magnetic flux is properly defined as the surface integral of the normal component of the magnetic field passing through a surface. If the magnetic field is constant, the magnetic flux passing through a surface of vector area S is
where "B" is the magnitude of the magnetic field (the magnetic flux density) having the unit of Wb/m (tesla), "S" is the area of the surface, and "θ" is the angle between the magnetic field lines and the normal (perpendicular) to S. For a varying magnetic field, we first consider the magnetic flux through an infinitesimal area element dS, where we may consider the field to be constant:
A generic surface, S, can then be broken into infinitesimal elements and the total magnetic flux through the surface is then the surface integral
From the definition of the magnetic vector potential A and the fundamental theorem of the curl the magnetic flux may also be defined as:
where the line integral is taken over the boundary of the surface "S", which is denoted ∂"S".

title: Demagnetizing field

text: The demagnetizing field, also called the stray field (outside the magnet), is the magnetic field (H-field) generated by the magnetization in a magnet. The total magnetic field in a region containing magnets is the sum of the demagnetizing fields of the magnets and the magnetic field due to any free currents or displacement currents. The term "demagnetizing field" reflects its tendency to act on the magnetization so as to reduce the total magnetic moment. It gives rise to "shape anisotropy" in ferromagnets with a single magnetic domain and to magnetic domains in larger ferromagnets.

title: Dynamo theory

text: Using Maxwell's equations simultaneously with the curl of Ohm's law, one can derive what is basically the linear eigenvalue equation for magnetic fields (B) which can be done when assuming that the magnetic field is independent from the velocity field. One arrives at a critical "magnetic Reynolds number" above which the flow strength is sufficient to amplify the imposed magnetic field, and below which it decays.

title: Sun

text: The solar magnetic field extends well beyond the Sun itself. The electrically conducting solar wind plasma carries the Sun's magnetic field into space, forming what is called the interplanetary magnetic field. In an approximation known as ideal magnetohydrodynamics, plasma particles only move along the magnetic field lines. As a result, the outward-flowing solar wind stretches the interplanetary magnetic field outward, forcing it into a roughly radial structure. For a simple dipolar solar magnetic field, with opposite hemispherical polarities on either side of the solar magnetic equator, a thin current sheet is formed in the solar wind. At great distances, the rotation of the Sun twists the dipolar magnetic field and corresponding current sheet into an Archimedean spiral structure called the Parker spiral. The interplanetary magnetic field is much stronger than the dipole component of the solar magnetic field. The Sun's dipole magnetic field of 50–400 μT (at the photosphere) reduces with the inverse-cube of the distance to about 0.1 nT at the distance of Earth. However, according to spacecraft observations the interplanetary field at Earth's location is around 5 nT, about a hundred times greater. The difference is due to magnetic fields generated by electrical currents in the plasma surrounding the Sun.

title: Magnetic field

text: Dynamo theory– a proposed mechanism for the creation of the Earth's magnetic field Helmholtz coil– a device for producing a region of nearly uniform magnetic field Magnetic field viewing film– Film used to view the magnetic field of an area Maxwell coil– a device for producing a large volume of an almost constant magnetic field Stellar magnetic field– a discussion of the magnetic field of stars Teltron tube– device used to display an electron beam and demonstrates effect of electric and magnetic fields on moving charges

title: Scanning SQUID microscope

text:
Magnetic current imaging uses the magnetic fields produced by currents in electronic devices to obtain images of those currents. This is accomplished though the fundamental physics relationship between magnetic fields and current, the Biot-Savart Law:
As a result, the current can be directly calculated from the magnetic field knowing only the separation between the current and the magnetic field sensor. The details of this mathematical calculation can be found elsewhere, but what is important to know here is that this is a direct calculation that is not influenced by other materials or effects, and that through the use of Fast Fourier Transforms these calculations can be performed very quickly. A magnetic field image can be converted to a current density image in about 1 or 2 seconds.

title: Hall effect sensor

text: When the Hall probe is held so that the magnetic field lines are passing at right angles through the sensor of the probe, the meter gives a reading of the value of magnetic flux density (B). A current is passed through the crystal which, when placed in a magnetic field has a "Hall effect" voltage developed across it. The Hall effect is seen when a conductor is passed through a uniform magnetic field. The natural electron drift of the charge carriers causes the magnetic field to apply a Lorentz force (the force exerted on a charged particle in an electromagnetic field) to these charge carriers. The result is what is seen as a charge separation, with a buildup of either positive or negative charges on the bottom or on the top of the plate. The crystal measures 5 mm square. The probe handle, being made of a non-ferrous material, has no disturbing effect on the field.

title: Fresnel equations

text: The behaviour of light striking the interface is solved by considering the electric and magnetic fields that constitute an electromagnetic wave, and the laws of electromagnetism as shown below. The ratio of waves' electric field (or magnetic field) amplitudes are supplied, but in practice one is more often interested in formulae which determine "power" coefficients, since power (or irradiance) is what can be directly measured at optical frequencies. The power of a wave is generally proportional to the square of the electric (or magnetic) field amplitude.


query: Where was Sir Harry Ricardo born?

title: Harry Ricardo

text: Harry Ricardo was born at 13 Bedford Square, London, in 1885, the eldest of three children, and only son of Halsey Ricardo, the architect, and his wife Catherine Jane, daughter of Sir Alexander Meadows Rendel, a civil engineer. Ricardo was descended from a brother of the famous political economist David Ricardo, a Sephardi Jew of Portuguese origin. He was one of the first people in England to see an automobile when his grandfather purchased one in 1898. He was from a relatively wealthy family and educated at Rugby School. In October 1903 he joined Trinity College, Cambridge as a civil engineering student. Ricardo had been using tools and building engines since the age of ten.[2]

title: Thomas Harris (Serjeant-at-Law)

text: There is a monument to Harris and his wife, Dame Elizabeth Harris (born Pomeroy), at the parish church in Cornworthy, Devon. Their eldest daughter Anne Southwell was born at Cornworthy Priory and she was baptised on 22 August 1584 at St Peters church in Cornworthy in Devon. Anne was a noted poet. Their eldest son Sir Edward Harris moved to Ireland where he became a prominent judge. Edward was the grandfather of the celebrated faith healer Valentine Greatrakes. He was buried in his local church at Kilcredan in County Cork, but the inscription on his parents' tomb strongly suggests that he was reinterred with them. They had two other children, Christopher, a soldier who was killed fighting in the Netherlands, and Honor, who married Sir Hugh Harris. The Haaris family died out in the male line in about 1643.

title: Ricardo (footballer, born 1971)

text: Ricardo came out of retirement in January 2013 to rejoin Osasuna as an emergency signing, after backup goalkeeper Asier Riesgo suffered a foot injury. At 41, he was the second-oldest player in the history of the Spanish top flight, surpassed only by 48-year-old Harry Lowe of Real Sociedad in 1935.

title: Ricardo plc

text: Harry (later Sir Harry) Ricardo was born in London in 1885 and was educated at Rugby and Cambridge where he studied at Trinity College. The first internal combustion engined cars were made by Daimler and Benz in the year of his birth and in his childhood days he was clearly highly influenced by these new forms of transport. He was renowned for his research into the problem of knock in engines; the results of his work on fuel and reducing fuel consumption assisted Alcock and Brown to cross the Atlantic for the first time by aircraft. Over the years, he was responsible for significant developments in the design of piston engines for a number of applications and derivatives of his original designs are still in production.

title: Niño Ricardo

text: Niño Ricardo died of cirrhosis of the liver in 1972 at the age of 67. A monument exists at his grave in the Cemetery San Fernando in Sevilla. It represents an angel lifting a guitar to Heaven. It is the work of sculptor Sandino and was funded with revenues from sales of a tribute album they recorded in 1972, in which a group of recording artists such as Paco de Lucia, Sabicas and Ricardo's son performed songs by Ricardo. In 2004, celebrations of the 100 years since the birth of Niño Ricardo were held in southern Spain. In 2005, they raised a monument and a plaque in the Plaza del Cristo de Burgos, near where Ricardo was born.

title: Harry Ricardo

text: Ricardo also assisted in the design of the combustion chambers and fuel control system of Sir Frank Whittle's jet engine.[15]

title: Lady Frieda Harris

text: Frieda and Percy Harris had two sons: Jack (born 1906, later Sir Jack Harris) and Thomas (born 1908).

title: Sir Harry (Canadian horse)

text: The Seagram Stables of Waterloo, Ontario were owned by the brothers Edward, Norman and Thomas Seagram. At age two, Sir Harry was raced at tracks in the Toronto area but had most of his success at two tracks in Montreal. At Blue Bonnets Raceway where he won the Kindergarten Stakes and on July 31, 1926 set a new track record of 0:59 1/5 for 5 furlongs on dirt. At Dorval Park, the track where the great Exterminator won his last race on June 21, 1924, Sir Harry won the 1926 Juvenile Stakes.

title: Ricardo Ramina

text: Ricardo Ramina was born in Curitiba, Brazil, where he studied medicine at the Pontifícia Universidade Católica do Paraná. After graduating he moved to Hannover, Germany, in order to do a Neurosurgery residency under Prof. Majid Samii at the KRH Klinikum Nordstadt. After concluding his residency, Ricardo Ramina, continued to work at the KRH Klinikum Nordstadt, where he eventually became senior attending physician.

title: Sir Harry Lewis

text: Sir Harry Lewis was acquired by the American businessman Howard Kaskel and sent to Europe where he was trained by Barry Hills at Lambourn in Berkshire.

title: Indirect injection

text:
It consists of a spherical chamber located in the cylinder head and separated from the engine cylinder by a tangential throat. About 50% of the air enters the swirl chamber during the compression stroke of the engine, producing a swirl.
After combustion, the products return through the same throat to the main cylinder at much higher velocity. So more heat loss to walls of the passage takes place. This type of chamber finds application in engines in which fuel control and engine stability are more important than fuel economy. These are Ricardo chambers, named after the inventor, Sir Harry Ricardo.

title: Sir Harry (British horse)

text: On 9 June Sir Harry competed in a Sweepstakes at Ascot which carried the condition that the winner must be offered for sale at 300 guineas. Sir Harry won the race from Wrangler and was duly bought by Mr Concannon, the owner of the runner-up. This was seen as an unfortunate result for Mr Bullock who had reportedly turned down an offer of 500 guineas for the horse on the previous day. Two weeks later, Sir Harry made his first appearance for his new owner in a King's Plate at Lewes where his opponents were Warter and Slapbang. In King's Plate races, horses carried heavy weights and raced in a series of four mile heats, with the prize going to the first horse to win twice. Sir Harry, carrying 168 pounds, finished last of the three runners behind Warter in the first heat, but then won the second. With Slapbang being withdrawn, the two winners then took part in deciding heat, which Sir Harry won to claim the prize, having galloped twelve miles in the course of the afternoon. Following this race, a match was arranged between Sir Harry and Warter on 7 August at Brighthelmston. Racing over one mile at level weights, Sir Harry started a slight favourite but was narrowly beaten by Lord Sackville's horse. The winning margin was so small that Concannon tried to claim a victory for Sir Harry before the official result was announced, creating "great confusion" among the racegoers. A week later, Sir Harry ran his last race in another King's Plate at Lewes. He finished second in the first heat and third in the second before being withdrawn. He was then retired to stud.

title: Paxman (engines)

text: Paxman is a major British brand of diesel engines. Ownership has changed on a number of occasions since the company's formation in 1865, and now the brand is owned by MAN SE, as part of MAN Diesel & Turbo. At its peak, the Paxman works covered and employed over 2,000 people. Engine production is still primarily based at Paxman's Colchester works. Early Paxman diesel engines (with "Comet" indirect injection cylinder heads, designed by Sir Harry Ricardo) carried the name Paxman Ricardo.

title: Harry Ricardo

text: Sir Harry Ralph Ricardo (26 January 1885 – 18 May 1974) was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine.

title: Triumph Ricardo

text: The Triumph Ricardo was a British single-cylinder motorcycle manufactured by the Triumph Engineering Co Ltd between 1921 and 1928. Named after engine designer Sir Harry Ricardo it featured an innovative four valve head design and was capable of over 70 mph, set three world speed records and won a gold medal in the 1923 International Six Day Trial.

title: Colin Bertram

text: He died in 2001, aged 89. He had married, in 1939, fellow zoologist Kate Ricardo, the daughter of consulting engineer Sir Harry Ricardo, FRS. They had four sons.

title: Sir Harry Smith Community College

text: Sir Harry Smith Community College is a secondary school in Whittlesey, Cambridgeshire. Opened in 1953 on the former site of the Whittlesey Workhouse, the College is named after 19th Century English Army General Sir Harry Smith who was born in Whittlesey, and whose grave is situated in the cemetery adjacent to the school. The college, originally known simply as the Sir Harry Smith School, specialises in science and mathematics.

title: University of Brighton

text: The University of Brighton and Ricardo UK jointly opened the Sir Harry Ricardo Laboratories on 14 November 2006. The laboratories are one of the largest UK research teams dedicated to internal combustion engines, the development of laser-based measurement techniques, fundamental modelling and computational simulation.

title: Ricardo plc

text: Started during Harry Ricardo's student days in Cambridge, the Dolphin project for a range of passenger cars was technically interesting, but ended in commercial collapse. Ricardo himself was not involved in owning or running the company, but its failure steered the young engineer away from manufacturing and towards research and development. Ricardo, while still at Cambridge, had patented an innovative split-cycle two-stroke layout, with the first cylinder pumping the compressed fuel-air mixture into the second, where the combustion took place. The combustion chamber was advanced, too, allowing a degree of charge stratification. His cousin, Ralph, who had the idea of starting the Dolphin motor car works in Shoreham, and was the main partner, centred the car's propulsion system on Harry's engine, as options for internal combustion engines in the early 1900s were very limited.

title: Flathead engine

text: An advance in flathead technology resulted from experimentation in the 1920s by Sir Harry Ricardo, who improved their efficiency after studying the gas-flow characteristics of sidevalve engines.

title: Edward Harris (Irish judge)

text: He was born at Cornworthy in Devon, eldest son and heir of Sir Thomas Harris of Cornworthy Priory, serjeant-at-law, by his wife Elizabeth Pomeroy (d.1634), daughter of Henry Pomeroy, who was a member of the ancient Anglo-Norman "de Pomeroy" family, feudal barons of Berry Pomeroy of Berry Pomeroy near Cornworthy. Sir Thomas Harris was called by his contemporary the Devon historian Tristram Risdon (d.1640) "a man much commended for his pregnant wit and learning". He sat in the House of Commons for many years, where he was noted both for his eloquence in debate and his diligence in committee work.

title: Anne Southwell

text: Southwell was born to Thomas and Elizabeth Harris of Cornworthy, Devon, where she was christened on 22 August 1574. Her brother was the prominent Irish judge Sir Edward Harris. Anne and her first husband moved to Ireland in the early seventeenth century, but little is known of their life there.

title: Augustine Harris

text: In his retirement Bishop Harris returned to his native Liverpool where he continued to serve the Church and administer the sacraments. To celebrate the 40th anniversary of his ordination as bishop, on 11 February 2006, Bishop Harris concelebrated Mass with Bishop John Crowley, his successor in Middlesbrough, and Msgr. Ricardo Morgan, at the time the Vicar General of the Diocese of Middlesbrough, in the chapel at Ince Blundell Hall where he has resided for the past few years.

title: Ricardo plc

text: Ricardo plc is a British publicly listed company named after its founder, Sir Harry Ricardo, originally incorporated and registered as Engine Patents Ltd. in 1915. Since 1919 the headquarters have been at Shoreham-by-Sea, West Sussex. Ricardo develops engines, transmissions, vehicle systems, intelligent transportation systems (ITS) and hybrid & electric systems. The industries served are in transportation, defence and clean energy.

title: Harry Ricardo

text: On 16 June 2005 a blue plaque was placed outside the house where Ricardo was born in Bedford Square, London. On 1 July 2010, the Institution of Mechanical Engineers bestowed an Engineering Heritage Award on Sir Harry Ricardo in recognition of his life and work as one of the foremost engineers of the twentieth century. The first internal combustion engine which Harry Ricardo designed and built as a schoolboy currently displays this Engineering Heritage plaque in the Ricardo plc company exhibition area. [17]

title: Harry Ricardo

text: British Rail 10100 Prosper L'Orange Ricardo plc Triumph Slant-4 engine Triumph Ricardo Francis Rodwell Banks

title: Frederick Verney

text: Verney was the youngest of four sons of Sir Harry Verney, 2nd Baronet and his first wife Eliza Hope, daughter of Admiral Sir George Hope-Vere. His father had been born Harry Calvert, inheriting the baronetcy from his father General Sir Harry Calvert, 1st Baronet, and had changed his surname to Verney in 1827 when he inherited the Verney family's estate in Aylesbury Vale, Buckinghamshire, including the John Adam-designed Claydon House. Sir Harry was a Liberal MP for a total of over 35 years.

title: Harry Ricardo

text: In 1927 Ricardo formed Ricardo Consulting Engineers (now known as Ricardo plc) in Shoreham-by-Sea, which has become one of the foremost automotive consulting firms worldwide and is publicly listed on the London Stock Exchange.

title: Sir Harry Smith, 1st Baronet

text: Harry Smith was appointed Adjutant-General in India in 1840, where he took part in the Gwalior campaign of 1843, for which he was appointed a Knight Commander of the Order of the Bath (KCB) and the First Anglo-Sikh War of 1845-46. He was in command of a division under Sir Hugh Gough at the battles of Mudki and Ferozeshah, where he conspicuously distinguished himself, but was insufficiently supported by the commander-in-chief. After the second of these actions Sir Harry Smith was appointed to an independent command, and on 28 January 1846 he inflicted a crushing defeat on the Sikhs at Aliwal on the Sutlej.

title: Harry Ricardo

text: In 1964 Ricardo retired from active work in Ricardo Consulting Engineers but kept in touch with various engineers within the company.


query: What is polemology?

title: War studies

text: War studies, sometimes called polemology, is the multi-disciplinary study of war. The word derives from Ancient Greek πόλεμος (pólemos, "war") + -logy".

title: Joan Botam

text: He was interested in the Catalan culture, and his work "Arnau de Vilanova, moralista" (1956) received the Jaume Serra i Húnter prize, which is given by the Institute of Catalan Studies. He has also been interested in hiking. In 1963 he was appointed vicar provincial of the Capuchin Friars of Catalonia, and he was at the same time chaplain of the ecumenical institution Pax Christi. From this position, he was engaged in several initiatives that were linked to pacifism and ecumenism. So he took part in the foundation of the Víctor Seix Institute of Polemology, he was part of the jury of the John XXIII Memorial and he cooperated actively in the anti-Francoist cultural resistance. He had an essential role in the Caputxinada of 1966. After that the Barcelona civil governor Antonio Ibáñez Freire tried to expel him from Spain, but the religious authorities and the Vatican avoided that.

title: Michel Maffesoli

text: In 1978, Michel Maffesoli became the teaching assistant of Julien Freund, a conservative political theorist and follower of Vilfredo Pareto, while he was lecturing in Strasbourg. Freund offered him to host the Institute of Polemology, which shows in his later works, under the themes of the "founding conflict" ("La violence fondatrice", 1978), the "conflictual society" (PhD dissertation, 1981), and the use of the myth of Dionysus as "regenerating disorder" ("L’Ombre de Dionysos", 1982).

title: Sophistic works of Antiphon

text: Most of the things which are legally just are [none the less] ... inimical to nature. By law it has been laid down for the eyes what they should see and what they should not see; for the ears what they should hear and they should not hear; for the tongue what it should speak, and what it should not speak; for the hands what they should do and what they should not do ... and for the mind what it should desire, and what it should not desire.

title: Franco Fornari

text: In the Sixties he became interested in polemology and founded the first "anti-H group" and the Italian Institute of Polemology (ISTIP).

title: What's On Kyiv

text:
"What's New" - A brief look at the news.
"What's Making Headlines" - Features about Ukrainian society and culture.
"What's On This Month" - Monthly listings of key entertainment events in Kyiv, broken down into Live Music, Art, Nightlife, Theatre, Family, etc., subsections.
"What's Ahead" - Future events of note planned for Kyiv.
"What's On the Rise" - Interview with a prominent or up-and-coming person.
"What's On Means Business" - Interviews and information related to the business community in Kyiv.
"What's In Focus" - Society section, photo report of recent social gatherings and business community meetings.
"What's On Around the Country" - Travel features from other destinations around Ukraine.
"What's On the Menu" - Reviews of local eateries.

title: Slavko Kulić

text: Kulić was born in Razvođe, Promina. He graduated from the Faculty of Business and Economics at the University of Zagreb, and made postgraduate studies in philosophy, politics, economics, law and sociology in Zagreb, Belgrade and Ljubljana. He made study visits to the U.S., the former U.S.S.R., China and Europe on the sociology of international relations, especially irenology (peace studies) and polemology (war studies) in the context of international relations.

title: Peace

text:
"Peace and conflict studies" is an [[academic field]] which identifies and analyses [[Violence|violent]] and [[Nonviolence|nonviolent]] behaviours, as well as the structural mechanisms attending violent and non violent [[social conflict]]s. This is to better understand the processes leading to a more desirable [[human condition]]. One variation,
"Peace studies" ([[irenology]]), is an [[Interdisciplinarity|interdisciplinary]] effort aiming at the prevention, [[de-escalation]], and solution of conflicts. This contrasts with [[war studies]] (polemology), directed at the efficient attainment of victory in conflicts. Disciplines involved may include [[political science]], [[geography]], [[economics]], [[psychology]], [[sociology]], [[international relations]], [[history]], [[anthropology]], [[religious studies]], and [[gender studies]], as well as a variety of other disciplines.

title: Egbert Jahn

text: At the beginning of 1968, while still a student in Marburg, he set up the High School Union for Peace and Conflict Research (originally the High School Union for Interdisciplinary Polemology) and was one of the first members of the Association of Peace and Conflict Research (AFK), which was also founded in 1968. After a brief period in 1969/70 as scientific assistant to Czempiel in Marburg, he went with the latter to Frankfurt am Main and in 1971 became the first research fellow at the Peace Research Institute Frankfurt (PRIF, "Hessische Stiftung Friedens- und Konfliktforschung", HSFK). Here from 1974 until the end of 1990, he became the director of the Research Group “Socialist States”. In 1975 he was offered the Professorship in Socio-Economic Structures, Institutions and Foreign Policy of Socialist Countries and then the Professorship of Political Science and Political Sociology at the Johann Wolfgang Goethe University in Frankfurt am Main He received a further offer in 1993, in succession to Hermann Weber, of the Chair of Political Science and Contemporary History at the University of Mannheim until September 2005. In 1992. while still in Frankfurt, he founded the Research Unit for Conflict and Cooperation Structures in Eastern Europe, Southeast Europe and Eurasia (FKKS) called the Mannheim here-named the Research Area for Conflict and Cooperation Structures in Eastern Europe. At the Mannheim Centre for European Social Research (MZES), he first headed a department and then later on until 2009 directed the Research Area “New Democracies and Conflict Resolution”.

title: Chandogya Upanishad

text: In its exposition of progressive meditation for Self-knowledge, the Chandogya Upanishad starts by referring to the outer worldly knowledges as name. Deeper than this name, is speech asserts verse 7.2.1, because speech is what communicates all outer worldly knowledge as well as what is right and what is wrong, what is true and what is false, what is good and what is bad, what is pleasant and what is unpleasant. Without speech, men can't share this knowledge, and one must adore and revere speech as manifestation of Brahman.

title: Louise Weiss

text: Louise Weiss came from a cosmopolitan family of Alsace. Her father, Paul Louis Weiss, a mining engineer, was a distinguished Alsatian Protestant from La Petite-Pierre. The ancestors of her Jewish mother, Jeanne Javal, originated from the small Alsatian town of Seppois-le-Bas. She grew up in Paris with five siblings, was trained as a teacher against the will of her family, was a teacher at a secondary school for arts and awarded a degree from Oxford University. From 1914 to 1918, she worked as a war nurse and founded a hospital in the Côtes-du-Nord. From 1918 to 1934, she was the publisher of the magazine, "". From 1935 to the beginning of World War II, she committed herself to women's suffrage. In 1936, she stood for French parliamentary elections, running in the Fifth arrondissement of Paris. During the War, she was active in the French Resistance. She claimed she was a member of the "Patriam Recuperare" network; however this was formally denied by members of the network. She was chief editor of the secret magazine, "Nouvelle République" from 1942 until 1944. In 1945, she founded the Institute for Polemology (research on war and conflict) together with in London. She travelled around the Middle East, Japan, China, Vietnam, Africa, Kenya, Madagascar, Alaska, India, etc., made documentary films and wrote accounts of her travels. In 1975, she unsuccessfully tried twice to be admitted to the Académie Française. In 1979, she became a Member of the European Parliament for the Gaullist Party (now The Republicans).

title: System Architect

text: A SQL-based query reporting language enables users to build and run reports to answer questions about the information they have modeled, such as what business processes are related to what organizational goals, what applications are used to perform what business processes, what business processes operate on what data entities, what user has modified what information on what date, and so forth.

title: What You Give Is What You Get

text:
US (promo only)
1.What You Give Is What You Get (edit)
2.What You Give Is What You Get (LP version)

title: War studies

text: Polemology is distinct from military history in that it encompasses a variety of fields:

title: What If? 2

text: What If? 2, subtitled More What If?: Eminent Historians Imagine What Might Have Been, is a collection of twenty-five essays dealing with counterfactual history. It was published by G.P. Putnam's Sons in 2001, , and edited by Robert Cowley. It is the successor of "What If?" It was combined with the original "What If?" in "The Collected What If?"

title: What If? (essays)

text: What If?, subtitled The World's Foremost Military Historians Imagine What Might Have Been, is a collection of twenty essays and thirteen sidebars dealing with counterfactual history. It was published by G.P. Putnam's Sons in 1999, , and this book as well as its two sequels, "What If? 2" and "What Ifs? of American History", were edited by Robert Cowley. It was later combined with "What If? 2" to form "The Collected What If?".

title: Etan Boritzer

text:
Boritzer gained national critical acclaim after "What is God?" was published in 1989 although the book has caused controversy from religious fundamentalists for its universalist views. The other current books in the "What is?" series include ""What is Love?, What is Death?, What is Beautiful?, What is Funny?, What is Right?, What is Peace?, What is Money?, What is Dreaming?, What is a Friend?, What is True?, What is a Family?, What is a Feeling?" The series is now also translated into 15 languages.
Boritzer was first published in 1963 at the age of 13 when he wrote an essay in his English class at Wade Junior High School in the Bronx, New York on the assassination of John F. Kennedy. His essay was included in a special anthology by New York City public school children compiled and published by the New York City Department of Education.

title: Iconoclasm

text: Lord what work was here! What clattering of glasses! What beating down of walls! What tearing up of monuments! What pulling down of seats! What wresting out of irons and brass from the windows! What defacing of arms! What demolishing of curious stonework! What tooting and piping upon organ pipes! And what a hideous triumph in the market-place before all the country, when all the mangled organ pipes, vestments, both copes and surplices, together with the leaden cross which had newly been sawn down from the Green-yard pulpit and the service-books and singing books that could be carried to the fire in the public market-place were heaped together.

title: Richard Muhlberger

text: Some of the most famous pieces Mühlberger has critiqued are done by Rembrandt, Leonardo da Vinci, and Pablo Picasso. Along with being a critic, Muhlberger was also a writer. He is known for a series containing critiques of illustrious authors. This series is made up of several books, "What makes a Rembrandt a Rembrandt?", "What makes a Van Gogh a Van Gogh?", "What makes a Monet a Monet?", "What makes a Degas a Degas?", "What makes a Cassatt a Cassatt?", "What makes a Goya a Goya?", "What makes a Bruegel a Bruegel?", What makes a Leonardo a Leonardo?", "What makes a Raphael a Raphael?", and "What makes a Picasso a Picasso?". More of his written works include a series titled "The Bible in Art". It contains the following books "Bible in Art: The Old Testament" and, "Bible in Art: The New Testament". Mühlberger's latest work is called "Charles Webster Hawthorne: Paintings and Watercolors".

title: Civil war

text: A civil war, also known as an intrastate war in polemology,[1] is a war between organized groups within the same state or country. The aim of one side may be to take control of the country or a region, to achieve independence for a region or to change government policies.[2] The term is a calque of the Latin bellum civile which was used to refer to the various civil wars of the Roman Republic in the 1st century BC.

title: Jurisprudence

text: In addition to the question, "What is law?", legal philosophy is also concerned with normative, or "evaluative" theories of law. What is the goal or purpose of law? What moral or political theories provide a foundation for the law? What is the proper function of law? What sorts of acts should be subject to punishment, and what sorts of punishment should be permitted? What is justice? What rights do we have? Is there a duty to obey the law? What value has the rule of law? Some of the different schools and leading thinkers are discussed below.

title: Javal family

text: Louise Weiss (1893, Arras, Pas-de-Calais - 26 May 1983, Paris) was a French author, journalist, feminist and European politician. She was awarded a degree from Oxford University. From 1914 to 1918, she worked as a war nurse and founded a hospital in the Côtes-du-Nord. From 1918 to 1934, she was the publisher of the magazine, "". From 1935 to the beginning of World War II, she committed herself to women's suffrage. In 1936, she stood for French parliamentary elections, running in the Fifth arrondissement of Paris. During the War, she was active in the French Resistance. She was a member of the "Patriam Recuperare" network, and she was chief editor of the secret magazine, "Nouvelle République" from 1942 until 1944. In 1945, she founded the Institute for Polemology (research on war and conflict) together with in London. She travelled around the Middle East, Japan, China, Vietnam, Africa, Kenya, Madagascar, Alaska, India, etc., made documentary films and wrote accounts of her travels. In 1975, she unsuccessfully tried twice to be admitted to the Académie Française. In 1979, she became a Member of the European Parliament for the Gaullist Party (now Union for a Popular Movement).

title: Vayeira

text: The Mishnah taught that some viewed the people of Sodom as embracing a philosophy of "what's mine is mine." The Mishnah taught that there are four types of people: (1) One who says: "What's mine is mine, and what's yours is yours"; this is a neutral type, some say this was the type of Sodom. (2) One who says: "What's mine is yours, and what's yours is mine"; this is an unlearned person. (3) One who says: "What's mine is yours, and what's yours is yours"; this is a pious person. And (4) one who says: "What's mine is mine, and what's yours is mine;" this is a wicked person.

title: War

text: The scholarly study of war is sometimes called polemology ( ), from the Greek "polemos", meaning "war", and "-logy", meaning "the study of".

title: What It Is

text: What It Is is a slang phrase popularized in the 1970s as a greeting or as another way to ask an individual about their well-being or general perception of things (similar to "How are you?", "How is it going?" or "What's Up?"). It is a shortening of the greeting, "What it is, what it was, and what it shall be," popular in the 1960s among African Americans.

title: Minos (dialogue)

text: Socrates: And so speech, in your view, is what is spoken, or sight what is seen, or hearing what is heard? Or is speech one thing, what is spoken another, sight one thing, what is seen another, hearing one thing, what is heard another—and so law one thing, what is accepted another? Is that so, or what is your view?

title: Bert Röling

text: Bernard Victor Aloysius (Bert) Röling (26 December 1906 – 16 March 1985) was a Dutch jurist and founding father of polemology in the Netherlands. Between 1946 and 1948 he acted as the Dutch representative for the International Military Tribunal for the Far East.

title: Bert Röling

text: In 1950 Röling was appointed professor at Groningen University where he founded the Institute for Polemology in 1962. He retired from academic life in 1977 but remained active for the Institute until his death in 1985.

title: What would Jesus do?

text: The expression has become a snowclone, sometimes for humorous effect. For example, "What Would Jesus Buy?", "What Would Lincoln Do?", "What Would Brian Boitano Do?", "What Would Mary Marvel Do?", "What Would Johnny Cash Do?", and "What would Tintin do?".

title: Ye Jacobites by Name

text:
What is Right, and What is Wrang, by the law, by the law?
What is Right and what is Wrang by the law?
What is Right, and what is Wrang?
A short sword, and a lang,
A weak arm and a strang, for to draw, for to draw
A weak arm and a strang, for to draw.


query: When did the Phanerozoic Eon begin?

title: Phanerozoic

text: The Phanerozoic Eon[3] is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present,[4] and began with the Cambrian Period when diverse hard-shelled animals first appeared. Its name was derived from the Ancient Greek words φανερός (phanerós) and ζωή (zōḗ), meaning visible life, since it was once believed that life began in the Cambrian, the first period of this eon. The term "Phanerozoic" was coined in 1930 by the American geologist George Halcott Chadwick (1876–1953).[5][6] The time before the Phanerozoic, called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.

title: Eonothem

text: Eonothems are subdivided into erathems and their smaller subdivisions within geology and paleobiology and their sub-fields, and a whole system of cross-disciplinary classification by strata is in place with oversight by the International Commission on Stratigraphy. Since oldest rocks are deposited first and lowest in a stratigraphic section, whether one is discussing the rock record is usually clear in context. (A fossil or feature present in the "upper Phanerozoic" eonothem (strata) would be discussed as being dated within the "later Phanerozoic" eon, whereas something found in the middle Phanerozoic could be discussing a layer, stage or the relative time.)

title: Stylemys

text:
Eon: Phanerozoic
Era: Cenozoic
Period: Paleogene
Epoch: Eocene

title: Cretaceous

text: The Cretaceous (/krɪˈteɪʃəs/, kri-TAY-shəs) is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago (mya) to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era, and the longest period of the Phanerozoic Eon. The Cretaceous Period is usually abbreviated K, for its German translation Kreide (chalk, creta in Latin).

title: Geological period

text: The twelve currently recognised periods of the present eon – the Phanerozoic – are defined by the International Commission on Stratigraphy (ICS) by reference to the stratigraphy at particular locations around the world.

title: Jan Veizer

text: In a letter to "Nature", Veizer et al.(2000), compared the reconstruction of tropical sea surface temperatures throughout the Phanerozoic eon (the past ~550 Myr) with the variable galactic cosmic rays and concluded that their results can be reconciled if atmospheric carbon dioxide concentrations were not the principal driver of climate variability on geological timescales for at least one-third of the Phanerozoic eon, or if the reconstructed carbon dioxide concentrations are not reliable.

title: Phanerozoic

text: The time span of the Phanerozoic starts with what appears to be the rapid emergence of a number of animal phyla; the evolution of those phyla into diverse forms; the emergence and development of complex plants; the evolution of fish; the emergence of insects and tetrapods; and the development of modern fauna. Plant life on land appeared in the early Phanerozoic eon. During this time span, tectonic forces caused the continents to move and eventually collect into a single landmass known as Pangaea (the most recent supercontinent), which then separated into the current continental landmasses.

title: Paleozoic

text: The Paleozoic (or Palaeozoic) Era (; from the Greek "palaios" (παλαιός), "old" and "zoe" (ζωή), "life", meaning "ancient life") is the earliest of three geologic eras of the Phanerozoic Eon. It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era.

title: Precambrian

text: The Precambrian (or Pre-Cambrian, sometimes abbreviated pЄ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.

title: Phanerozoic

text: The Quaternary spans from 2.58 million years ago to present day, and is the shortest geological period in the Phanerozoic Eon. It features modern animals, and dramatic changes in the climate. It is divided into two epochs: the Pleistocene and the Holocene.

title: History of Earth

text: The Hadean eon represents the time before a reliable (fossil) record of life; it began with the formation of the planet and ended 4.0 billion years ago. The following Archean and Proterozoic eons produced the beginnings of life on Earth and its earliest evolution. The succeeding eon is the Phanerozoic, divided into three eras: the Palaeozoic, an era of arthropods, fishes, and the first life on land; the Mesozoic, which spanned the rise, reign, and climactic extinction of the non-avian dinosaurs; and the Cenozoic, which saw the rise of mammals. Recognizable humans emerged at most 2 million years ago, a vanishingly small period on the geological scale.

title: Era

text:
In large-scale natural science, there is need for another time perspective, independent from human activity, and indeed spanning a far longer period (mainly prehistoric), where "geologic era" refers to well-defined time spans.
The next-larger division of geologic time is the eon. The Phanerozoic Eon is subdivided into eras. There are currently three eras defined in the Phanerozoic; the following table lists them from youngest to oldest (BP is an abbreviation for "before present").

title: Proterozoic

text: Classically, the boundary between the Proterozoic and the Phanerozoic eons was set at the base of the Cambrian Period when the first fossils of animals including trilobites and archeocyathids appeared. In the second half of the 20th century, a number of fossil forms have been found in Proterozoic rocks, but the upper boundary of the Proterozoic has remained fixed at the base of the Cambrian, which is currently placed at 541 Ma.

title: EOne

text: The eOne was available at Circuit City and Micro Center, but it did not sell well in the few months when it was available due to a lawsuit from Apple which eventually caused the eOne to be widely considered a failure for eMachines. The eOne is no longer in production as it was discontinued in 2002 and became quite rare to come by nowadays.

title: Eonothem

text: Eonothems have the same names as their corresponding eons, which means during the history of the Earth only four eonothems were formed. Oldest to newest these are the Hadean, Archean, Proterozoic, and Phanerozoic.

title: Paleogene

text: The Paleogene (; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The Paleogene is most notable for being the time during which mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cretaceous Period. The United States Geological Survey uses the abbreviation P for the Paleogene.

title: Ediacaran

text: The Ediacaran Period (), spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia.

title: Jan Veizer

text: Veizer, J., Godderis, Y. & François. L.M., Evidence for decoupling of atmospheric and global climate during the Phanerozoic eon. "Nature" 408, 698-701 (2000)

title: Pan-African Ocean

text: The Pan-African Ocean is a hypothesized paleo-ocean whose closure created the supercontinent of Pannotia. The ocean may have existed before the break-up of the supercontinent of Rodinia. The ocean closed before the beginning of the Phanerozoic Eon, when the Panthalassa ocean expanded, and was eventually replaced by it.

title: Era (geology)

text: A geologic era is a subdivision of geologic time that divides an eon into smaller units of time. The Phanerozoic Eon is divided into three such time frames: the Paleozoic, Mesozoic, and Cenozoic (meaning "old life", "middle life" and "recent life") that represent the major stages in the macroscopic fossil record. These eras are separated by catastrophic extinction boundaries, the P-T boundary between the Paleozoic and the Mesozoic and the K-Pg boundary between the Mesozoic and the Cenozoic. There is evidence that catastrophic meteorite impacts played a role in demarcating the differences between the eras.

title: Geologic time scale

text: The primary defined divisions of time are eons, in sequence the Hadean, the Archean, the Proterozoic and the Phanerozoic. The first three of these can be referred to collectively as the Precambrian supereon. Eons are divided into eras, which are in turn divided into periods, epochs and ages.

title: Hoppin Formation

text:
The Hoppin Formation named for Hoppin Hill in North Attleborough, Massachusetts, contains Early Cambrian fossils associated with the explosion of multi-cellular life, beginning 541 million years ago at the start of the Phanerozoic Eon.
The bottom rock units of the formation are arkose quartzite, conglomerate and sandstone. The quartzite lies on top and was sourced from the underlying Dedham Granite. Upper units in the formation include green and red slate shale, calcareous nodules and layers of red, argillite limestone.

title: Precambrian

text: The term "Precambrian" is recognized by the International Commission on Stratigraphy as the only "supereon" in geologic time; it is so called because it includes the Hadean (~4.6—4 billion), Archean (4—2.5 billion), and Proterozoic (2.5 billion—541 million) eons. (There is only one other eon: the Phanerozoic, 541 million-present.) "Precambrian" is still used by geologists and paleontologists for general discussions not requiring the more specific eon names. , the United States Geological Survey considers the term informal, lacking a stratigraphic rank.

title: Precambrian

text: Excluding a few contested reports of much older forms from North America and India, the first complex multicellular life forms seem to have appeared at roughly 1500 Ma, in the Mesoproterozoic era of the Proterozoic eon. Fossil evidence from the later Ediacaran period of such complex life comes from the Lantian formation, at least 580 million years ago. A very diverse collection of soft-bodied forms is found in a variety of locations worldwide and date to between 635 and 542 Ma. These are referred to as Ediacaran or Vendian biota. Hard-shelled creatures appeared toward the end of that time span, marking the beginning of the Phanerozoic eon. By the middle of the following Cambrian period, a very diverse fauna is recorded in the Burgess Shale, including some which may represent stem groups of modern taxa. The increase in diversity of lifeforms during the early Cambrian is called the Cambrian explosion of life.

title: Proterozoic

text: The Proterozoic Eon was a very tectonically active period in the Earth’s history. The late Archean Eon to Early Proterozoic Eon corresponds to a period of increasing crustal recycling, suggesting subduction. Evidence for this increased subduction activity comes from the abundance of old granites originating mostly after 2.6 Ga. The appearance of eclogites, which metamorphic rocks created by high pressure (>1 GPa), are explained using a model that incorporates subduction. The lack of eclogites that date to the Archean Eon suggests that conditions at that time did not favor the formation of high grade metamorphism and therefore did not achieve the same levels of subduction as was occurring in the Proterozoic Eon. As a result of remelting of basaltic oceanic crust due to subduction, the cores of the first continents grew large enough to withstand the crustal recycling processes. The long-term tectonic stability of those cratons is why we find continental crust ranging up to a few billion years in age. It is believed that 43% of modern continental crust was formed in the Proterozoic, 39% formed in the Archean, and only 18% in the Phanerozoic. Studies by Condie 2000 and Rino et al. 2004 suggest that crust production happened episodically. By isotopically calculating the ages of Proterozoic granitoids it was determined that there were several episodes of rapid increase in continental crust production. The reason for these pulses is unknown, but they seemed to have decreased in magnitude after every period.

title: Copernican period

text: Its Earth equivalents are the Neoproterozoic era of the Proterozoic eon and the whole of the Phanerozoic eon. So, while animal life bloomed on Earth, the Moon's geologic activity was coming to an end.

title: Changhsingian

text: The greatest mass extinction in the Phanerozoic eon, the Permian–Triassic extinction event, occurred during this age. The extinction rate peaked about a million years before the end of this stage.

title: Fortunian

text: The Fortunian stage marks the beginning of the Phanerozoic eon, the Paleozoic era, and the Cambrian period. It is the first of the two stages of the Terreneuvian series. Its base is defined as the first appearance of the trace fossil "Treptichnus pedum" million years ago. The top of the Fortunian which is the base of the Stage 2 of the Cambrian has not been formally defined yet, but will correspond to the appearance of an Archeocyatha species or "Small shelly fossils" approximately million years ago.

title: History of Earth

text: The Phanerozoic is the current eon on Earth, which started approximately 542 million years ago. It consists of three eras: The Paleozoic, Mesozoic, and Cenozoic, and is the time when multi-cellular life greatly diversified into almost all the organisms known today.

title: Geological history of Earth

text: The Phanerozoic Eon is the current eon in the geologic timescale. It covers roughly 541 million years. During this period continents drifted about, eventually collected into a single landmass known as Pangea and then split up into the current continental landmasses.