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The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era, after a geological crust started to solidify following the earlier molten Hadean eon. There are microbial mat fossils such as stromatolites found in 3.48 billion-year-old sandstone discovered in Wester...	History of Earth	Wikipedia	500	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The history of the Earth can be organized chronologically according to the geologic time scale, which is split into intervals based on stratigraphic analysis. Solar System formation The standard model for the formation of the Solar System (including the Earth) is the solar nebula hypothesis. In this model, the Solar ...	History of Earth	Wikipedia	446	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The proto-Earth grew by accretion until its interior was hot enough to melt the heavy, siderophile metals. Having higher densities than the silicates, these metals sank. This so-called iron catastrophe resulted in the separation of a primitive mantle and a (metallic) core only 10 million years after the Earth began to ...	History of Earth	Wikipedia	512	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Formation of the Moon Earth's only natural satellite, the Moon, is larger relative to its planet than any other satellite in the Solar System. During the Apollo program, rocks from the Moon's surface were brought to Earth. Radiometric dating of these rocks shows that the Moon is 4.53 ± 0.01 billion years old, formed ...	History of Earth	Wikipedia	507	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The initial crust, which formed when the Earth's surface first solidified, totally disappeared from a combination of this fast Hadean plate tectonics and the intense impacts of the Late Heavy Bombardment. However, it is thought that it was basaltic in composition, like today's oceanic crust, because little crustal diff...	History of Earth	Wikipedia	503	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
In early models for the formation of the atmosphere and ocean, the second atmosphere was formed by outgassing of volatiles from the Earth's interior. Now it is considered likely that many of the volatiles were delivered during accretion by a process known as impact degassing in which incoming bodies vaporize on impact....	History of Earth	Wikipedia	491	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The first step in the emergence of life may have been chemical reactions that produced many of the simpler organic compounds, including nucleobases and amino acids, that are the building blocks of life. An experiment in 1952 by Stanley Miller and Harold Urey showed that such molecules could form in an atmosphere of wat...	History of Earth	Wikipedia	480	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
In 2003 it was proposed that porous metal sulfide precipitates would assist RNA synthesis at about and at ocean-bottom pressures near hydrothermal vents. In this hypothesis, the proto-cells would be confined in the pores of the metal substrate until the later development of lipid membranes. Metabolism first: iron–sul...	History of Earth	Wikipedia	495	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Research in 2003 reported that montmorillonite could also accelerate the conversion of fatty acids into "bubbles", and that the bubbles could encapsulate RNA attached to the clay. Bubbles can then grow by absorbing additional lipids and dividing. The formation of the earliest cells may have been aided by similar proces...	History of Earth	Wikipedia	468	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Most of the life that covers the surface of the Earth depends directly or indirectly on photosynthesis. The most common form, oxygenic photosynthesis, turns carbon dioxide, water, and sunlight into food. It captures the energy of sunlight in energy-rich molecules such as ATP, which then provide the energy to make sugar...	History of Earth	Wikipedia	457	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Photosynthesis had another major impact. Oxygen was toxic; much life on Earth probably died out as its levels rose in what is known as the oxygen catastrophe. Resistant forms survived and thrived, and some developed the ability to use oxygen to increase their metabolism and obtain more energy from the same food. Snowb...	History of Earth	Wikipedia	319	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
However, the term Snowball Earth is more commonly used to describe later extreme ice ages during the Cryogenian period. There were four periods, each lasting about 10 million years, between 750 and 580 million years ago, when the Earth is thought to have been covered with ice apart from the highest mountains, and avera...	History of Earth	Wikipedia	390	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Around this time, the first proto-mitochondrion was formed. A bacterial cell related to today's Rickettsia, which had evolved to metabolize oxygen, entered a larger prokaryotic cell, which lacked that capability. Perhaps the large cell attempted to digest the smaller one but failed (possibly due to the evolution of pre...	History of Earth	Wikipedia	383	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Archaeans, bacteria, and eukaryotes continued to diversify and to become more complex and better adapted to their environments. Each domain repeatedly split into multiple lineages. Around 1.1 Ga, the plant, animal, and fungi lines had split, though they still existed as solitary cells. Some of these lived in colonies, ...	History of Earth	Wikipedia	415	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
After the break-up of Rodinia about 800 Ma, the continents may have formed another short-lived supercontinent around 550 Ma. The hypothetical supercontinent is sometimes referred to as Pannotia or Vendia. The evidence for it is a phase of continental collision known as the Pan-African orogeny, which joined the continen...	History of Earth	Wikipedia	411	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The Cryogenian period was followed by the Ediacaran period, which was characterized by a rapid development of new multicellular lifeforms. Whether there is a connection between the end of the severe ice ages and the increase in diversity of life is not clear, but it does not seem coincidental. The new forms of life, ca...	History of Earth	Wikipedia	429	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The Cenozoic ("new life") era began at Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven subdivisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene divided into the Miocene, Pliocene, and the Quaternary compos...	History of Earth	Wikipedia	383	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The continents Laurentia and Baltica collided between 450 and 400 Ma, during the Caledonian Orogeny, to form Laurussia (also known as Euramerica). Traces of the mountain belt this collision caused can be found in Scandinavia, Scotland, and the northern Appalachians. In the Devonian period (416–359 Ma) Gondwana and Sibe...	History of Earth	Wikipedia	468	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
During the Cambrian, the first vertebrate animals, among them the first fishes, had appeared. A creature that could have been the ancestor of the fishes, or was probably closely related to it, was Pikaia. It had a primitive notochord, a structure that could have developed into a vertebral column later. The first fishes...	History of Earth	Wikipedia	383	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Several hundred million years ago, plants (probably resembling algae) and fungi started growing at the edges of the water and then out of it. The oldest fossils of land fungi and plants date to 480–460 Ma, though molecular evidence suggests the fungi may have colonized the land as early as 1000 Ma and the plants 700 Ma...	History of Earth	Wikipedia	464	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
After yet another, the most severe extinction of the period (251~250 Ma), around 230 Ma, dinosaurs split off from their reptilian ancestors. The Triassic–Jurassic extinction event at 200 Ma spared many of the dinosaurs, and they soon became dominant among the vertebrates. Though some mammalian lines began to separate d...	History of Earth	Wikipedia	428	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
The fifth and most recent mass extinction was the Cretaceous-Paleogene extinction event. In 66 Ma, a asteroid struck Earth just off the Yucatán Peninsula—somewhere in the southwestern tip of then Laurasia—where the Chicxulub crater is today. This ejected vast quantities of particulate matter and vapor into the air tha...	History of Earth	Wikipedia	502	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Three million years ago saw the start of the Pleistocene epoch, which featured dramatic climatic changes due to the ice ages. The ice ages led to the evolution and expansion of modern man in Saharan Africa. The mega-fauna that dominated fed on grasslands that, by now, had taken over much of the subtropical world. The l...	History of Earth	Wikipedia	394	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
It is more difficult to establish the origin of language; it is unclear whether Homo erectus could speak or if that capability had not begun until Homo sapiens. As brain size increased, babies were born earlier, before their heads grew too large to pass through the pelvis. As a result, they exhibited more plasticity, t...	History of Earth	Wikipedia	485	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Agriculture had a major impact; humans began to affect the environment as never before. Surplus food allowed a priestly or governing class to arise, followed by increasing division of labor. This led to Earth's first civilization at Sumer in the Middle East, between 4000 and 3000 BC. Additional civilizations quickly ar...	History of Earth	Wikipedia	499	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
In the 14th century, the Renaissance began in Italy with advances in religion, art, and science. At that time the Christian Church as a political entity lost much of its power. In 1492, Christopher Columbus reached the Americas, initiating great changes to the new world. European civilization began to change beginning ...	History of Earth	Wikipedia	130	2068726	https://en.wikipedia.org/wiki/History%20of%20Earth	Physical sciences	Earth science	null
Calamine, also known as calamine lotion, is a medication made from powdered calamine mineral that is used to treat mild itchiness. Conditions treated include sunburn, insect bites, poison ivy, poison oak, and other mild skin conditions. It may also help dry out secretions resulting from skin irritation. It is applied o...	Calamine	Wikipedia	280	2070264	https://en.wikipedia.org/wiki/Calamine	Biology and health sciences	Specific drugs	Health
A spindle is a straight spike, usually made from wood, used for spinning, twisting fibers such as wool, flax, hemp, cotton into yarn. It is often weighted at either the bottom, middle, or top, commonly by a disc or spherical object called a whorl; many spindles, however, are weighted simply by thickening their shape to...	Spindle (textiles)	Wikipedia	437	2070483	https://en.wikipedia.org/wiki/Spindle%20%28textiles%29	Technology	Spinning	null
Most supported spindles continue to rest with the tip on one's thigh, on the ground, on a table, or in a small bowl while rotating. Supported spindles come in a great variety of sizes, such as the very large, ~30" Navajo spindle, the small, extremely fast, metal takli for spinning cotton, and the tiniest Orenburg spin...	Spindle (textiles)	Wikipedia	416	2070483	https://en.wikipedia.org/wiki/Spindle%20%28textiles%29	Technology	Spinning	null
Another way spindles are categorised is by the location of the whorl. The whorl, where present, may be located near the top, bottom or center of the spindle. For example a top-whorl drop spindle will have the whorl located near the top of the shaft underneath a hook that allows the spindle to suspend as it is being spu...	Spindle (textiles)	Wikipedia	486	2070483	https://en.wikipedia.org/wiki/Spindle%20%28textiles%29	Technology	Spinning	null
Whorls can be located near the top, middle or bottom of the spindle shaft. Whorl location can affect the stability of the spindle, with bottom whorl spindles being considered more stable. Cop The cop is not initially an intrinsic part of the spindle; however, as it is formed it plays a part in the spindle anatomy. On...	Spindle (textiles)	Wikipedia	437	2070483	https://en.wikipedia.org/wiki/Spindle%20%28textiles%29	Technology	Spinning	null
Supported spindles Supported spindles spin on surfaces such as bowls that are usually ceramic or wooden. This type of spindle gives the user more control of the weight of the yarn. The various types of supported spindles range due to the difference in styles of spinning and yarn weight. Navajo spindles have longer shaf...	Spindle (textiles)	Wikipedia	400	2070483	https://en.wikipedia.org/wiki/Spindle%20%28textiles%29	Technology	Spinning	null
Xiphactinus (from Latin and Greek for "sword-ray") is an extinct genus of large predatory marine ray-finned fish that lived during the late Albian to the late Maastrichtian. The genus grew up to in length, and superficially resembled a gargantuan, fanged tarpon. It is a member of the extinct order Ichthyodectiformes, ...	Xiphactinus	Wikipedia	438	2071899	https://en.wikipedia.org/wiki/Xiphactinus	Biology and health sciences	Prehistoric osteichthyans	Animals
Like modern tarpons, Xiphactinus likely spent its juvenile stage of life in shallow seaway margins for protection and to utilize rich food resources, possibly rare in open marine water, though this needs confirmation due to the lack of shallow, nearshore deposits from the Western Interior Seaway. The teeth of the juven...	Xiphactinus	Wikipedia	463	2071899	https://en.wikipedia.org/wiki/Xiphactinus	Biology and health sciences	Prehistoric osteichthyans	Animals
A scimitar ( or ) is a single-edged sword with a convex curved blade of about 76.2 to 91.44cm (30 to 36 inches) associated with Middle Eastern, South Asian, or North African cultures. A European term, scimitar does not refer to one specific sword type, but an assortment of different Eastern curved swords inspired by ty...	Scimitar	Wikipedia	445	21476681	https://en.wikipedia.org/wiki/Scimitar	Technology	Swords	null
The scimitar was widespread throughout the Middle East from at least the Ottoman period until the age of smokeless powder firearms relegated swords to dress and ceremonial function. The Egyptian khopesh, brought to Egypt by the Hyksos, resembled scimitars. The khopesh is sometimes considered a scimitar. Early swords in...	Scimitar	Wikipedia	341	21476681	https://en.wikipedia.org/wiki/Scimitar	Technology	Swords	null
The sword (or saif) is an important symbol in Arab cultures, and is used as a metaphor in many phrases in the Arabic language. The word occurs also in various symbolic and status titles in Arabic (and adopted in other languages) used in Islamic states, notably: In the Yemenite independent imamate: Saif al-Haqq, meani...	Scimitar	Wikipedia	420	21476681	https://en.wikipedia.org/wiki/Scimitar	Technology	Swords	null
The scimitar appears as a symbol of the Russians in the Finnish coat of arms of the Province of Karelia, which depicts two armored arms fighting with swords – one Western and one Eastern, representing Karelia's troubled history as a border region between the east and the west. From this context, the sword and scimitar ...	Scimitar	Wikipedia	276	21476681	https://en.wikipedia.org/wiki/Scimitar	Technology	Swords	null
In media Scimitars were used by Calormene warriors and royalty in The Chronicles of Narnia, such as The Horse and His Boy and The Last Battle. In the 1975 film Monty Python and the Holy Grail, a character says: "If I went 'round, sayin' I was an emperor, just because some moistened bint had lobbed a scimitar at me, t...	Scimitar	Wikipedia	244	21476681	https://en.wikipedia.org/wiki/Scimitar	Technology	Swords	null
A wheelchair is a mobilized form of chair using 2 or more wheels, a footrest, and an armrest usually cushioned. It is used when walking is difficult or impossible to do due to illnesses, injury, disabilities, or age-related health conditions. Wheelchairs provide mobility, postural support, and freedom to those who cann...	Wheelchair	Wikipedia	477	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
In 1655, Stephan Farffler, a 22-year-old paraplegic watchmaker, built the world's first self-propelling chair on a three-wheel chassis using a system of cranks and cogwheels. However, the device resembled a hand bike more than a wheelchair since the design included hand cranks mounted at the front wheel. A self-propel...	Wheelchair	Wikipedia	450	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
A self-propelled manual wheelchair incorporates a frame, seat, one or two footplates (footrests), and four wheels: usually two caster wheels at the front and two large wheels at the back. There will generally also be a separate seat cushion. The larger rear wheels usually have push-rims of slightly smaller diameter pro...	Wheelchair	Wikipedia	400	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Many rigid models are made with light materials such as aluminium and titanium, and wheelchairs of composite materials such as carbon-fibre have started to appear. Ultra lightweight rigid wheelchairs are commonly known as 'active user chairs' as they are ideally suited to independent use. Another innovation in rigid ch...	Wheelchair	Wikipedia	493	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Light weight and high costs are related to the manual wheelchair market. At the low-cost end, heavy, folding steel chairs with sling seats and little adaptability dominate. Users may be temporarily disabled, or using such a chair as a loaner, or simply unable to afford better. These chairs are common as "loaners" at la...	Wheelchair	Wikipedia	442	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Powerchairs are commonly divided by their access capabilities. An indoor-chair may only reliably be able to cross completely flat surfaces, limiting them to household use. An indoor-outdoor chair is less limited, but may have restricted range or ability to deal with slopes or uneven surfaces. An outdoor chair is more c...	Wheelchair	Wikipedia	434	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Opinions are often polarized as to whether mobility scooters should be considered wheelchairs or not, and negative stereotyping of scooter users can be worse than for some manual or power-chair users. Some commercial organisations draw a distinction between power-chairs and scooters when making access provisions due t...	Wheelchair	Wikipedia	371	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
In the case of reclining wheelchairs, the seat-back tilts back, and the leg rests can be raised, while the seat base remains in the same position, somewhat similar to a common recliner chair. Some reclining wheelchairs lean back far enough that the user can lie down completely flat. Reclining wheelchairs are preferred...	Wheelchair	Wikipedia	383	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
A standing wheelchair is one that supports the user in a nearly standing position. They can be used as both a wheelchair and a standing frame, allowing the user to sit or stand in the wheelchair as they wish. Some versions are entirely manual, others have a powered stand on an otherwise manual chair, while others have ...	Wheelchair	Wikipedia	480	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
All-terrain wheelchairs can allow users to access terrain otherwise completely inaccessible to a wheelchair user. Two different formats have been developed. One hybridises wheelchair and mountain bike technology, generally taking the form of a frame within which the user sits and with four mountain bike wheels at the c...	Wheelchair	Wikipedia	482	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
A variation on the manually-propelled wheelchair is the Leveraged Freedom Chair (LFC), designed by the MIT Mobility Lab. This wheelchair is designed to be low-cost, constructed with local materials, for users in developing countries. Engineering modifications have added hand-controlled levers to the LFC, to enable user...	Wheelchair	Wikipedia	262	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
A recent development related to wheelchairs is the handcycle. They come in a variety of forms, from the road and track racing models to off-road types modelled after mountain bikes. While dedicated handcycle designs are manufactured, clip-on versions are available that can convert a manual wheelchair to a handcycle in ...	Wheelchair	Wikipedia	500	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Experiments have also been made with unusual variant wheels, like the omniwheel or the Mecanum wheel. These allow for a broader spectrum of movement, but have made no mass-market penetration. The electric wheelchair shown on the right is fitted with Mecanum wheels (sometimes known as Ilon wheels) which give it complete...	Wheelchair	Wikipedia	105	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Other variants Foot propulsion of a manual wheelchair by the occupant is possible for users who have limited hand movement capabilities or simply do not wish to use their hands for propulsion. Foot propulsion also allows patients to exercise their legs to increase blood flow and limit further disability. Users who do...	Wheelchair	Wikipedia	480	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Buildings Adapting the built environment to make it more accessible to wheelchair users is one of the key campaigns of disability rights movements and local equality legislation such the Americans with Disabilities Act of 1990 (ADA). The social model of disability defines 'disability' as the discrimination experienced...	Wheelchair	Wikipedia	393	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
The same principles of access that apply to public buildings also apply to private homes and may be required as part of local building regulations. Important adaptations include external access, providing sufficient space for a wheelchair user to move around the home, doorways that are wide enough for convenient use, a...	Wheelchair	Wikipedia	334	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Vehicles Public transit vehicles are increasingly required to be accessible to people who use wheelchairs. In the UK, all single deck buses are required to be accessible to wheelchair users by 2017, all double-deck coaches by 2020. Similar requirements exist for trains, with most trains already incorporating a number...	Wheelchair	Wikipedia	495	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Some elements of the outdoor public realm present barriers to wheelchair use, such as grade-separated areas where no ramps are provided. UK guidance recommends a minimum width of 1.5m for a wheelchair user and an ambulant pedestrian to move side by side; with maximum ramp gradients of 8% for manual wheelchair use (5% i...	Wheelchair	Wikipedia	462	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Accessories There is a wide range of accessories for wheelchairs. There are cushions, cup holders, seatbelts, storage bags, lights, and more. A wheelchair user uses seatbelts for security or posture. Some wheelchair users want to use a seatbelt to make sure they never fall out of the wheelchair. Other wheelchair users ...	Wheelchair	Wikipedia	102	21481546	https://en.wikipedia.org/wiki/Wheelchair	Technology	Devices	null
Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms, "crickets" were placed at the family level (i.e. Gryllidae), but contemporary authorities including Otte now place them in the superfamily Grylloidea. The word has been used in ...	Cricket (insect)	Wikipedia	368	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Crickets often appear as characters in literature. The Talking Cricket features in Carlo Collodi's 1883 children's book, The Adventures of Pinocchio, and in films based on the book. The insect is central to Charles Dickens's 1845 The Cricket on the Hearth and George Selden's 1960 The Cricket in Times Square. Crickets a...	Cricket (insect)	Wikipedia	503	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
The largest members of the family are the -long bull crickets (Brachytrupes) which excavate burrows a metre or more deep. The tree crickets (Oecanthinae) are delicate white or pale green insects with transparent fore wings, while the field crickets (Gryllinae) are robust brown or black insects. Distribution and habita...	Cricket (insect)	Wikipedia	405	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Other defensive strategies are the use of camouflage, fleeing, and aggression. Some species have adopted colourings, shapes, and patterns that make it difficult for predators that hunt by sight to detect them. They tend to be dull shades of brown, grey, and green that blend into their background, and desert species ten...	Cricket (insect)	Wikipedia	450	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Crickets chirp at different rates depending on their species and the temperature of their environment. Most species chirp at higher rates the higher the temperature is (about 62 chirps a minute at in one common species; each species has its own rate). The relationship between temperature and the rate of chirping is kn...	Cricket (insect)	Wikipedia	510	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Gryllus firmus exhibits wing polymorphism; some individuals have fully functional, long hind wings and others have short wings and cannot fly. The short-winged females have smaller flight muscles, greater ovarian development, and produce more eggs, so the polymorphism adapts the cricket for either dispersal or reproduc...	Cricket (insect)	Wikipedia	480	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Most crickets lay their eggs in the soil or inside the stems of plants, and to do this, female crickets have a long, needle-like or sabre-like egg-laying organ called an ovipositor. Some ground-dwelling species have dispensed with this, either depositing their eggs in an underground chamber or pushing them into the wal...	Cricket (insect)	Wikipedia	444	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Predators, parasites, and pathogens Crickets have many natural enemies and are subject to various pathogens and parasites. They are eaten by large numbers of vertebrate and invertebrate predators and their hard parts are often found during the examination of animal intestines. Mediterranean house geckos (Hemidactylus t...	Cricket (insect)	Wikipedia	485	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
The phylogenetic relationships of the Gryllidae, summarized by Darryl Gwynne in 1995 from his own work (using mainly anatomical characteristics) and that of earlier authors, are shown in the following cladogram, with the Orthoptera divided into two main groups, Ensifera (crickets sensu lato) and Caelifera (grasshoppers...	Cricket (insect)	Wikipedia	499	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Strictly, taxa in Infraorder Tettigoniidea and other superfamilies are excluded Tettigoniidae – the bush crickets or katydids – which are quite distinct and unrelated, with 4-segmented tarsi (at least in the middle and hind legs) and females with flattened ovipositors. Also note: within this family is the genus An...	Cricket (insect)	Wikipedia	384	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Crickets feature as major characters in novels and children's books. Charles Dickens's 1845 novella The Cricket on the Hearth, divided into sections called "Chirps", tells the story of a cricket which chirps on the hearth and acts as a guardian angel to a family. Carlo Collodi's 1883 children's book "Le avventure di Pi...	Cricket (insect)	Wikipedia	407	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Crickets are kept as pets and are considered good luck in some countries; in China, they are sometimes kept in cages or in hollowed-out gourds specially created in novel shapes. The practice was common in Japan for thousands of years; it peaked in the 19th century, though crickets are still sold at pet shops. It is al...	Cricket (insect)	Wikipedia	461	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
By the 19th century "cricket" and "crickets" were in use as euphemisms for using Christ as an interjection. The addition of "Jiminy" (a variation of "Gemini"), sometimes shortened to "Jimmy" created the expressions "Jiminy Cricket!" or "Jimmy Crickets!" as less blasphemous alternatives to exclaiming "Jesus Christ!" By...	Cricket (insect)	Wikipedia	294	21481963	https://en.wikipedia.org/wiki/Cricket%20%28insect%29	Biology and health sciences	Orthoptera	null
Scansoriopterygidae (meaning "climbing wings") is an extinct family of climbing and gliding maniraptoran dinosaurs. Scansoriopterygids are known from five well-preserved fossils, representing four species, unearthed in the Tiaojishan Formation fossil beds (dating to the mid-late Jurassic Period) of Liaoning and Hebei, ...	Scansoriopterygidae	Wikipedia	466	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
Other features shared within the group include short and high skulls with down turned lower jaws and large front teeth, and long arms. Tail length, however, varied significantly among scansoriopterygids. Epidexipteryx had a short tail (70% the length of the torso), anchoring long tail feathers, while Scansoriopteryx ha...	Scansoriopterygidae	Wikipedia	496	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
Turner, Makovicky and Norell (2012) included only Epidexipteryx hui in their primary phylogenetic analysis, as a full-grown specimen of this species is known; regarding Scansoriopteryx/Epidendrosaurus, the authors were worried that including it in the primary analysis would be problematic, because it is only known from...	Scansoriopterygidae	Wikipedia	285	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
A monophyletic Scansoriopterygidae was recovered by Godefroit et al. (2013); the authors found scansoriopterygids to be basalmost members of Paraves and the sister group to the clade containing Avialae and Deinonychosauria. Agnolín and Novas (2013) recovered scansoriopterygids as non-paravian maniraptorans and the sist...	Scansoriopterygidae	Wikipedia	454	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
The scansoriopterygids would have lived alongside synapsids such as the aquatic Castorocauda, arboreal gliding mammal Volaticotherium and various types of gliding haramiyidans, the rhamphorhynchoid pterosaurs Jeholopterus and Pterorhynchus, as well as a diverse range of insect life (including mayflies and beetles) and ...	Scansoriopterygidae	Wikipedia	376	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
In describing Scansoriopteryx, Czerkas and Yuan also described evidence for an arboreal lifestyle. They noted that, unlike all modern bird hatchlings, the forelimbs of Scansoriopteryx are longer than the hind limbs. The authors argued that this anomaly indicates the forelimbs played an important role in locomotion even...	Scansoriopterygidae	Wikipedia	462	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
Yi also preserves feathers. These are notably very simple for a member of Pennaraptora (a clade of which scansoriopterygids are usually considered members), being "paintbrush-like", with long quill-like bases topped by sprays of thinner filaments. The feathers covered most of the body, starting near the tip of the snou...	Scansoriopterygidae	Wikipedia	286	3857434	https://en.wikipedia.org/wiki/Scansoriopterygidae	Biology and health sciences	Theropods	Animals
Pupfish are a group of small killifish belonging to ten genera of the family Cyprinodontidae of ray-finned fish. Pupfish are especially noted for being found in extreme and isolated situations. They are primarily found in North America, South America, and the Caribbean region. As of August 2006, 120 nominal species and...	Pupfish	Wikipedia	485	3861311	https://en.wikipedia.org/wiki/Pupfish	Biology and health sciences	Acanthomorpha	Animals
Cualac Miller, 1956 Cubanichthys C.L. Hubbs, 1926 Cyprinodon Lacepède, 1803 Floridichthys C.L. Hubbs, 1926 Garmanella C.L. Hubbs, 1936 Jordanella Goode & Bean, 1879 †Megupsilon Miller & Walters, 1972 (extinct 2014) Orestias Valenciennes 1839 Pseudorestias Arratia, Vila, Lam, Guerrero & Quezada-Romegialli, 2017...	Pupfish	Wikipedia	406	3861311	https://en.wikipedia.org/wiki/Pupfish	Biology and health sciences	Acanthomorpha	Animals
The pupfish found in Death Valley were once thought to be one main species. They were once all found in Lake Manly, a glacial lake over 620 square miles (1,600 km2), roughly 185,000-128,000 years ago. Over time this lake dried up and started to separate into smaller lakes or ponds. As this drying happened the pupfish b...	Pupfish	Wikipedia	226	3861311	https://en.wikipedia.org/wiki/Pupfish	Biology and health sciences	Acanthomorpha	Animals
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or bioenergy, or relatively con...	Variable renewable energy	Wikipedia	430	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Intermittency or variability is the extent to which a power source fluctuates. This has two aspects: a predictable variability, such as the day-night cycle, and an unpredictable part (imperfect local weather forecasting). The term intermittent can be used to refer to the unpredictable part, with variable then referring...	Variable renewable energy	Wikipedia	493	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Wind-generated power is a variable resource, and the amount of electricity produced at any given point in time by a given plant will depend on wind speeds, air density, and turbine characteristics, among other factors. If wind speed is too low then the wind turbines will not be able to make electricity, and if it is to...	Variable renewable energy	Wikipedia	510	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Because wind power is generated by large numbers of small generators, individual failures do not have large impacts on power grids. This feature of wind has been referred to as resiliency. Solar power Intermittency inherently affects solar energy, as the production of renewable electricity from solar sources depends ...	Variable renewable energy	Wikipedia	494	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
The displaced dispatchable generation could be coal, natural gas, biomass, nuclear, geothermal or storage hydro. Rather than starting and stopping nuclear or geothermal, it is cheaper to use them as constant base load power. Any power generated in excess of demand can displace heating fuels, be converted to storage or ...	Variable renewable energy	Wikipedia	480	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Some gas, or hydro power plants are partially loaded and then controlled to change as demand changes or to replace rapidly lost generation. The ability to change as demand changes is termed "response". The ability to quickly replace lost generation, typically within timescales of 30 seconds to 30 minutes, is termed "...	Variable renewable energy	Wikipedia	485	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
At times of low load where non-dispatchable output from wind and solar may be high, grid stability requires lowering the output of various dispatchable generating sources or even increasing controllable loads, possibly by using energy storage to time-shift output to times of higher demand. Such mechanisms can include: ...	Variable renewable energy	Wikipedia	465	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Multiple wind farms spread over a wide geographic area and gridded together produce power more constantly and with less variability than smaller installations. Wind output can be predicted with some degree of confidence using weather forecasts, especially from large numbers of turbines/farms. The ability to predict win...	Variable renewable energy	Wikipedia	512	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Sector coupling Demand and generation can be better matched when sectors such as mobility, heat and gas are coupled with the power system. The electric vehicle market is for instance expected to become the largest source of storage capacity. This may be a more expensive option appropriate for high penetration of varia...	Variable renewable energy	Wikipedia	479	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Maximum penetration limits Maximum penetration of combined wind and solar is estimated at around 70% to 90% without regional aggregation, demand management or storage; and up to 94% with 12 hours of storage. Economic efficiency and cost considerations are more likely to dominate as critical factors; technical solutions...	Variable renewable energy	Wikipedia	252	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Transmission capacity: transmission capacity may be more expensive than for nuclear and coal generating capacity due to lower load factors. Transmission capacity will generally be sized to projected peak output, but average capacity for wind will be significantly lower, raising cost per unit of energy actually transmit...	Variable renewable energy	Wikipedia	398	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
Germany In countries with a considerable amount of renewable energy, solar energy causes price drops around noon every day. PV production follows the higher demand during these hours. The images below show two weeks in 2022 in Germany, where renewable energy has a share of over 40%. Prices also drop every night and we...	Variable renewable energy	Wikipedia	203	34578727	https://en.wikipedia.org/wiki/Variable%20renewable%20energy	Technology	Concepts	null
In chemical kinetics, the overall rate of a reaction is often approximately determined by the slowest step, known as the rate-determining step (RDS or RD-step or r/d step) or rate-limiting step. For a given reaction mechanism, the prediction of the corresponding rate equation (for comparison with the experimental rate ...	Rate-determining step	Wikipedia	374	1427634	https://en.wikipedia.org/wiki/Rate-determining%20step	Physical sciences	Kinetics	Chemistry
First step rate-determining In fact, however, the observed reaction rate is second-order in and zero-order in CO, with rate equation r = k[]2. This suggests that the rate is determined by a step in which two molecules react, with the CO molecule entering at another, faster, step. A possible mechanism in two elementar...	Rate-determining step	Wikipedia	360	1427634	https://en.wikipedia.org/wiki/Rate-determining%20step	Physical sciences	Kinetics	Chemistry
Pre-equilibrium: if the second step were rate-determining The other possible case would be that the second step is slow and rate-determining, meaning that it is slower than the first step in the reverse direction: r2 ≪ r−1. In this hypothesis, r1 − r−1 ≈ 0, so that the first step is (almost) at equilibrium. The overall...	Rate-determining step	Wikipedia	464	1427634	https://en.wikipedia.org/wiki/Rate-determining%20step	Physical sciences	Kinetics	Chemistry
In contrast, the alkaline hydrolysis of methyl bromide () is a bimolecular nucleophilic substitution (SN2) reaction in a single bimolecular step. Its rate law is second-order: r = k[R−Br][]. Composition of the transition state A useful rule in the determination of mechanism is that the concentration factors in the rat...	Rate-determining step	Wikipedia	446	1427634	https://en.wikipedia.org/wiki/Rate-determining%20step	Physical sciences	Kinetics	Chemistry
Diffusion control In the previous examples the rate determining step was one of the sequential chemical reactions leading to a product. The rate-determining step can also be the transport of reactants to where they can interact and form the product. This case is referred to as diffusion control and, in general, occurs ...	Rate-determining step	Wikipedia	86	1427634	https://en.wikipedia.org/wiki/Rate-determining%20step	Physical sciences	Kinetics	Chemistry
Collision theory is a principle of chemistry used to predict the rates of chemical reactions. It states that when suitable particles of the reactant hit each other with the correct orientation, only a certain amount of collisions result in a perceptible or notable change; these successful changes are called successful...	Collision theory	Wikipedia	434	1427763	https://en.wikipedia.org/wiki/Collision%20theory	Physical sciences	Kinetics	Chemistry
where: k is the rate constant in units of (number of molecules)−1⋅s−1⋅m3. nA is the number density of A in the gas in units of m−3. nB is the number density of B in the gas in units of m−3. E.g. for a gas mixture with gas A concentration 0.1 mol⋅L−1 and B concentration 0.2 mol⋅L−1, the number of density of A is 0.1×6...	Collision theory	Wikipedia	285	1427763	https://en.wikipedia.org/wiki/Collision%20theory	Physical sciences	Kinetics	Chemistry

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