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Science (from the Latin word scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3500 to 3000 BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages, but was preserved in the Muslim world during the Islamic Golden Age. The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived "natural philosophy", which was later transformed by the Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions. The scientific method soon played a greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape; along with the changing of "natural philosophy" to "natural science."
Modern science is typically divided into three major branches that consist of the natural sciences (e.g., biology, chemistry, and physics), which study nature in the broadest sense; the social sciences (e.g., economics, psychology, and sociology), which study individuals and societies; and the formal sciences (e.g., logic, mathematics, and theoretical computer science), which study abstract concepts. There is disagreement, however, on whether the formal sciences actually constitute a science as they do not rely on empirical evidence. Disciplines that use existing scientific knowledge for practical purposes, such as engineering and medicine, are described as applied sciences.
Science is based on research, which is commonly conducted in academic and research institutions, as well as in government agencies and companies. The practical impact of scientific research has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the development of commercial products, armaments, health care, and environmental protection. (Full article...)
Selected article
Two reconstructed S. validum skeletons based on specimen UALVP 2, Royal Tyrrell Museum
Stegoceras is a genus of pachycephalosaurid (dome-headed) dinosaur that lived in what is now North America during the Late Cretaceous period, about 77.5 to 74 million years ago (mya). The first specimens from Alberta, Canada, were described in 1902, and the type species Stegoceras validum was based on these remains. The generic name means "horn roof", and the specific name means "strong". Several other species have been placed in the genus over the years, but these have since been moved to other genera or deemed junior synonyms. Currently only S. validum and S. novomexicanum, named in 2011 from fossils found in New Mexico, remain. The validity of the latter species has also been debated.
Stegoceras was a small, bipedal dinosaur about 2 to 2.5 metres (6.6 to 8.2 ft) long, and weighed around 10 to 40 kilograms (22 to 88 lb). It had a rigid vertebral column, and a stiffened tail. The pelvic region was broad, perhaps due to an extended gut. The skull was roughly triangular with a short snout, and had a thick, broad, and relatively smooth dome on the top. The back of the skull had a thick "shelf" over the occiput, and it had a thick ridge over the eyes. Much of the skull was ornamented by tubercles (or round "outgrowths") and nodes (or "knobs"), many in rows, and the largest formed small horns on the shelf. The teeth were small and serrated. The skull is thought to have been flat in juvenile animals and to have grown into a dome with age. (Full article...)
Painted by Castelnau, 1856 (left to right, top to bottom): Fistularia tabacaria, Mylossoma duriventre, Mesonauta acora, Corydoras splendens, Pseudacanthicus spinosus, Acanthurus coeruleus, Stegastes pictus
Teleostei /tɛliːˈɒstiːaɪ/ (Greek: teleios "complete" + osteon "bone"), members of which are known as teleosts /ˈtɛliːɒsts/, is by far the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Teleosts are arranged into about 40 orders and 448 families. Over 26,000 species have been described. Teleosts range from giant oarfish measuring 7.6 m (25 ft) or more, and ocean sunfish weighing over 2 t (2.0 long tons; 2.2 short tons), to the minute male anglerfish Photocorynus spiniceps, just 6.2 mm (0.24 in) long. Including not only torpedo-shaped fish built for speed, teleosts can be flattened vertically or horizontally, be elongated cylinders or take specialised shapes as in anglerfish and seahorses. Teleosts dominate the seas from pole to pole and inhabit the ocean depths, estuaries, rivers, lakes and even swamps.
The difference between teleosts and other bony fish lies mainly in their jaw bones; teleosts have a movable premaxilla and corresponding modifications in the jaw musculature which make it possible for them to protrude their jaws outwards from the mouth. This is of great advantage, enabling them to grab prey and draw it into the mouth. In more derived teleosts, the enlarged premaxilla is the main tooth-bearing bone, and the maxilla, which is attached to the lower jaw, acts as a lever, pushing and pulling the premaxilla as the mouth is opened and closed. Other bones further back in the mouth serve to grind and swallow food. Another difference is that the upper and lower lobes of the tail (caudal) fin are about equal in size. The spine ends at the caudal peduncle, distinguishing this group from other fish in which the spine extends into the upper lobe of the tail fin. (Full article...)
The Rodrigues rail (Erythromachus leguati), also known as Leguat's gelinote or Leguat's rail, is an extinct species of the rail family that was endemic to the Mascarene island of Rodrigues, east of Madagascar in the Indian Ocean. It is generally kept in its own genus, Erythromachus, but has sometimes been assigned to the genus Aphanapteryx along with its close relative the red rail (A. bonasia) of Mauritius; their relationship with other rails is unclear. The Rodrigues rail was about 35 cm (14 in) long and weighed at least 500 g (18 oz). It was described as having grey plumage, a red beak, red legs, and a naked red patch around the eye. The beak was long and curved downwards. It was flightless and fed on tortoise eggs. It was described as being attracted to red objects, which humans exploited while hunting it.
The Rodrigues rail is believed to have become extinct in the mid-18th century because of predation by introduced cats and destruction of its habitat by tortoise hunters. The bird was first documented from life by two contemporaneous accounts; first by François Leguat, a French Huguenot refugee marooned on Rodrigues in 1691, and then by Julien Tafforet, marooned on the island in 1726. Subfossil remains were later discovered and connected with the old accounts in 1874, and the species was named E. leguati in Leguat's honour. (Full article...)
The Metacomet Ridge, Metacomet Ridge Mountains, or Metacomet Range of southern New England is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and rare or endangered plants. The ridge is an important recreation resource located within 10 miles (16 km) of more than 1.5 million people, offering four long-distance hiking trails and over a dozen parks and recreation areas, including several historic sites. It has been the focus of ongoing conservation efforts because of its natural, historic, and recreational value, involving municipal, state, and national agencies and nearly two dozen non-profit organizations.
The Metacomet Ridge extends from Branford, Connecticut on Long Island Sound, through the Connecticut River Valley region of Massachusetts, to northern Franklin County, Massachusetts, 2 miles (3 km) short of the Vermont and New Hampshire borders for a distance of 100 miles (160 km). It is geologically distinct from the nearby Appalachian Mountains and surrounding uplands, and is composed of volcanic basalt (also known as trap rock) and sedimentary rock in faulted and tilted layers many hundreds of feet thick. In most cases, the basalt layers are dominant, prevalent, and exposed. The ridge rises dramatically from much lower valley elevations, although only 1,200 feet (370 m) above sea level at its highest, with an average summit elevation of 725 feet (221 m). (Full article...)- Taare Zameen Par (titled Like Stars on Earth internationally) is a 2007 Indian Hindi-language drama film produced and directed by Aamir Khan. The film explores the life and imagination of Ishaan, an 8-year-old dyslexic child. Although he excels in art, his poor academic performance leads his parents to send him to a boarding school. Ishaan's new art teacher suspects that he is dyslexic and helps him to overcome his disability. Darsheel Safary stars as 8-year-old Ishaan, and Aamir Khan plays his art teacher.
Creative director and writer Amole Gupte initially developed the idea with his wife Deepa Bhatia, who served as the film's editor. Shankar–Ehsaan–Loy composed the film's score, and Prasoon Joshi wrote the lyrics for many of the songs. Principal photography took place in Mumbai and in Panchgani's New Era High School, and some of the school's students make appearances. (Full article...) - Sir Robert Eric Mortimer Wheeler FRS FBA FSA (10 September 1890 – 22 July 1976) was a British archaeologist and officer in the British Army. Over the course of his career, he served as Director of both the National Museum of Wales and London Museum, Director-General of the Archaeological Survey of India, and the founder and Honorary Director of the Institute of Archaeology in London, in addition to writing twenty-four books on archaeological subjects.
Born in Glasgow to a middle-class family, Wheeler was raised largely in Yorkshire before moving to London in his teenage years. After studying classics at University College London (UCL), he began working professionally in archaeology, specialising in the Romano-British period. During World War I he volunteered for service in the Royal Artillery, being stationed on the Western Front, where he rose to the rank of major and was awarded the Military Cross. Returning to Britain, he obtained his doctorate from UCL before taking on a position at the National Museum of Wales, first as Keeper of Archaeology and then as Director, during which time he oversaw excavation at the Roman forts of Segontium, Y Gaer, and Isca Augusta with the aid of his first wife, Tessa Wheeler. Influenced by the archaeologist Augustus Pitt Rivers, Wheeler argued that excavation and the recording of stratigraphic context required an increasingly scientific and methodical approach, developing the "Wheeler method". In 1926, he was appointed Keeper of the London Museum; there, he oversaw a reorganisation of the collection, successfully lobbied for increased funding, and began lecturing at UCL. (Full article...)
The geology of the Zion and Kolob canyons area includes nine known exposed formations, all visible in Zion National Park in the U.S. state of Utah. Together, these formations represent about 150 million years of mostly Mesozoic-aged sedimentation in that part of North America. Part of a super-sequence of rock units called the Grand Staircase, the formations exposed in the Zion and Kolob area were deposited in several different environments that range from the warm shallow seas of the Kaibab and Moenkopi formations, streams and lakes of the Chinle, Moenave, and Kayenta formations to the large deserts of the Navajo and Temple Cap formations and dry near shore environments of the Carmel Formation.
Subsequent uplift of the Colorado Plateau slowly raised these formations much higher than where they were deposited. This steepened the stream gradient of the ancestral rivers and other streams on the plateau. The faster-moving streams took advantage of uplift-created joints in the rocks to remove all Cenozoic-aged formations and cut gorges into the plateaus. Zion Canyon was cut by the North Fork of the Virgin River in this way. Lava flows and cinder cones covered parts of the area during the later part of this process. (Full article...)
The Guilden Morden boar is a sixth- or seventh-century Anglo-Saxon copper alloy figure of a boar that may have once served as the crest of a helmet. It was found around 1864 or 1865 in a grave in Guilden Morden, a village in the eastern English county of Cambridgeshire. There the boar attended a skeleton with other objects, including a small earthenware bead with an incised pattern, although the boar is all that now remains. Herbert George Fordham, whose father originally discovered the boar, donated it to the British Museum in 1904; as of 2018 it was on view in room 41.
The boar is simply designed, distinguished primarily by a prominent mane; eyes, eyebrows, nostrils and tusks are only faintly present. A pin and socket design formed by the front and hind legs suggests that the boar was mounted on another object, such as a helmet. Such is the case on one of the contemporary Torslunda plates found in Sweden, where boar-crested helmets are depicted similarly. (Full article...)
Tropical Storm Gabrielle was a short-lived tropical cyclone that passed over North Carolina before tracking out to sea. The seventh named storm of the 2007 Atlantic hurricane season, Gabrielle developed as a subtropical cyclone on September 8 about 385 miles (625 km) southeast of Cape Lookout, North Carolina. Unfavorable wind shear impacted the storm for much of its duration, although a temporary decrease in the shear allowed the cyclone to become a tropical storm. On September 9, Gabrielle made landfall at Cape Lookout National Seashore in the Outer Banks of North Carolina with winds of 60 mph (90 km/h). Turning to the northeast, the storm quickly weakened and dissipated on September 11.
In advance of the storm, tropical cyclone watches and warnings were issued for coastal areas, while rescue teams and the U.S. Coast Guard were put on standby. The storm dropped heavy rainfall near its immediate landfall location but little precipitation elsewhere. Along the coast of North Carolina, high waves, rip currents, and storm surge were reported. Slight localized flooding was reported. Gusty winds also occurred, though no wind damage was reported. Along the coast of Florida, rough surf drowned one person. Overall damage was minor. (Full article...)
Hydrochloric acid or muriatic acid is a colorless inorganic chemical system with the formula HCl. Hydrochloric acid has a distinctive pungent smell. It is classified as strongly acidic and can attack the skin over a wide composition range, since the hydrogen chloride completely dissociates in an aqueous solution.
Hydrochloric acid is the simplest chlorine-based acid system containing water. It is a solution of hydrogen chloride and water, and a variety of other chemical species, including hydronium and chloride ions. It is a naturally-occurring component of the gastric acid produced in the digestive systems of most animal species, including humans. (Full article...)- Tumbler Ridge is a district municipality in the foothills of the B.C. Rockies in northeastern British Columbia, Canada, and a member municipality of the Peace River Regional District. With a population of 1,987 (2016) living in a townsite, the municipality encompasses an area of 1,558 km2 (602 sq mi) of mostly Crown land. The townsite is located near the confluence of the Murray River and Flatbed Creek and the intersection of Highway 52 and Highway 29 and includes the site of the Tumbler Ridge Secondary School and Tumbler Ridge Airport. It is part of the Peace River South provincial electoral district and the Prince George—Peace River—Northern Rockies federal riding.
Tumbler Ridge is a planned community with the housing and infrastructure construct built simultaneously in 1981 by the provincial government to service the coal industry as part of the British Columbia Resources Investment Corporation's Northeast Coal Development. In 1981, a consortium of Japanese steel mills agreed to purchase 100 million tonnes of coal over 15 years for US$7.5 billion from two mining companies, Denison Mines Inc. and the Teck Corporation, who were to operate the Quintette mine and the Bullmoose mine respectively. Declining global coal prices after 1981, and weakening Asian markets in the late 1990s, made the town's future uncertain and kept it from achieving its projected population of 10,000 people. The uncertainty dissuaded investment and kept the economy from diversifying. When price reductions were forced onto the mines, the Quintette mine was closed in 2000 production and the town lost about half its population. Coal prices began to rise after the turn of the century, leading to the opening of the Peace River Coal Trend mine by Northern Energy & Mining Inc. (now owned by Anglo American Met Coal) and the Wolverine Mine, originally owned by Western Canadian Coal, which was purchased by Walter Energy in 2010. Walter went bankrupt in 2015, and their Canadian assets—including the Wolverine Mine—were purchased by Conuma Coal in 2016. (Full article...) - Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction. Different characteristics tend to exist within any given population as a result of mutation, genetic recombination and other sources of genetic variation. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or rare within a population. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms and molecules.
The scientific theory of evolution by natural selection was conceived independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century and was set out in detail in Darwin's book On the Origin of Species. Evolution by natural selection was first demonstrated by the observation that more offspring are often produced than can possibly survive. This is followed by three observable facts about living organisms: (1) traits vary among individuals with respect to their morphology, physiology and behaviour (phenotypic variation), (2) different traits confer different rates of survival and reproduction (differential fitness) and (3) traits can be passed from generation to generation (heritability of fitness). Thus, in successive generations members of a population are more likely to be replaced by the progenies of parents with favourable characteristics that have enabled them to survive and reproduce in their respective environments. In the early 20th century, other competing ideas of evolution such as mutationism and orthogenesis were refuted as the modern synthesis reconciled Darwinian evolution with classical genetics, which established adaptive evolution as being caused by natural selection acting on Mendelian genetic variation. (Full article...)
The white-eyed river martin (Pseudochelidon sirintarae) is a passerine bird, one of only two members of the river martin subfamily of the swallows. Since it has significant differences from its closest relative, the African river martin, it is sometimes placed in its own genus, Eurochelidon. First found in 1968, it is known only from a single wintering site in Thailand, and may be extinct, since it has not been seen since 1980 despite targeted surveys in Thailand and neighbouring Cambodia. It may possibly still breed in China or Southeast Asia, but a Chinese painting initially thought to depict this species was later reassessed as showing pratincoles.
The adult white-eyed river martin is a medium-sized swallow, with mainly glossy greenish-black plumage, a white rump, and a tail which has two elongated slender central tail feathers, each widening to a racket-shape at the tip. It has a white eye ring and a broad, bright greenish-yellow bill. The sexes are similar in appearance, but the juvenile lacks the tail ornaments and is generally browner than the adult. Little is known of the behaviour or breeding habitat of this martin, although like other swallows it feeds on insects caught in flight, and its wide bill suggests that it may take relatively large species. It roosts in reed beds in winter, and may nest in river sandbanks, probably in April or May before the summer rains. It may have been overlooked prior to its discovery because it tended to feed at dawn or dusk rather than during the day. (Full article...)
In 1257, a catastrophic eruption occurred at Samalas volcano on the Indonesian island of Lombok. The event had a probable Volcanic Explosivity Index of 7, making it one of the largest volcanic eruptions during the current Holocene epoch. It created eruption columns reaching tens of kilometres into the atmosphere and pyroclastic flows that buried much of Lombok and crossed the sea to reach the neighbouring island of Sumbawa. The flows destroyed human habitations, including the city of Pamatan, which was the capital of a kingdom on Lombok. Ash from the eruption fell as far as 340 kilometres (210 mi) away in Java; the volcano deposited more than 10 cubic kilometres (2.4 cu mi) of rocks and ash.
The eruption was witnessed by people who recorded it on the , a document written on palm leaves. It left behind a large caldera that contains Lake Segara Anak. Later volcanic activity created more volcanic centres in the caldera, including the Barujari cone, which remains active. The aerosols injected into the atmosphere reduced the solar radiation reaching the Earth's surface, cooling the atmosphere for several years and leading to famines and crop failures in Europe and elsewhere, although the exact scale of the temperature anomalies and their consequences is still debated. The eruption may have helped trigger the Little Ice Age, a centuries-long cold period during the last thousand years. Before the site of the eruption was known, an examination of ice cores around the world had found a large spike in sulfate deposition around 1257, providing strong evidence of a large volcanic eruption having occurred somewhere in the world. In 2013, scientists linked the historical records about Mount Samalas to these spikes. (Full article...)
Freedom Planet is a 2D platform video game developed and published by GalaxyTrail, a studio set up by designer Stephen DiDuro. The player controls one of three anthropomorphic animal protagonists: the dragon Lilac, the wildcat Carol, or the basset hound Milla. Aided by the duck-like Torque, the player attempts to defeat Lord Brevon, who plans to conquer the galaxy. While the game focuses on fast-paced platforming, its levels are interspersed with slower action scenes.
The game began development as a Sonic the Hedgehog fangame using characters created by DeviantArt user Ziyo Ling for its main cast. Early into development, DiDuro lost interest in creating a derivative work and reconceived the project as his own intellectual property. Sash Lilac, originally a hedgehog, became a dragon; antagonist Doctor Eggman was replaced by Lord Brevon; and the Sonic series' ring-based health system was abandoned. Further changes were suggested by fans and incorporated throughout development. Freedom Planet was developed in Denmark and the United States, with its art direction carrying East Asian influences, such as medieval Chinese art inspiring its background visuals. (Full article...)
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A railgun is a form of gun that converts electrical energy—rather than the more conventional chemical energy from an explosive propellant—into projectile kinetic energy. It is not to be confused with a coilgun (Gauss gun). The term railgun is also used for conventional firearms used in the Unlimited class of benchrest shooting.
A Railgun is a type of Magnetic Accelerator Gun (MAG) that utilizes an electromagnetic force to propel an electrically conductive projectile that is initially part of the current path. Sometimes they also use a movable armature connecting the rails. The current flowing through the rails sets up a magnetic field between them and through the projectile perpendicularly to the current in it. This results in the rails and the projectile pushing each other and in the acceleration of the projectile along the rails.
Selected biography
Did you know...
- ...that space artist Jon Lomberg (artwork pictured) was Carl Sagan's principal artistic collaborator on many projects such as Cosmos and the Voyager Golden Record?
- ...that NASA astronaut Stephen Robinson has logged 497 hours in space?
- ...that Othniel Charles Marsh named two species of the dinosaur Coelurus from the same quarry, not knowing that the bones belonged to the same skeleton?
- ...that the type specimen of Dromicosuchus had damage to its jaw and neck that may have been inflicted by the teeth of the large carnivore it was found underneath?
- ...that the scientific name of the common Australian garden fungus Aseroë rubra means 'red disgusting juice'?
Science News
- 30 December 2020 – 2020 in paleontology
- Scientists at the Russian Academy of Sciences announce the discovery of a "well-preserved" woolly rhinoceros carcass in Abyysky District, Sakha, Russia, which was revealed by melting permafrost in August. The Russian Academy of Sciences says that the woolly rhinoceros was likely 3 or 4 years old when it died by drowning in the river, and could be anywhere from 20,000 to 50,000 years old. (ABC News)
- 18 December 2020 –
- A review of some recent medical studies shows that memory T cells may play a role in a phenomenon known as cross-reactivity, which researchers found may perhaps give certain people, in some cases, some level of immunity to the virus that causes COVID-19 even without them having been exposed to or infected with the virus, or having received a vaccine. There are certain structural and clinical similarities between the virus that causes COVID-19 and the other coronaviruses that are related to it, which cause SARS and MERS. (MSN)
- 16 December 2020 – Chinese space program
- China National Space Administration (CNSA) spacecraft Chang'e 5 returns to Earth carrying samples of lunar rocks and soil from the surface of the Moon. The capsule will be airlifted to Beijing for formal opening and the samples will be made available to scientists in other countries, according to the CNSA. (The Guardian)
- 6 December 2020 – Uncrewed spaceflights to the International Space Station
- A SpaceX Falcon 9 launches a cargo ship into orbit to re-supply the International Space Station. (CBS News)
- 1 December 2020 – 2020 SO
- Unknown astronomical object 2020 SO makes its closest approach to Earth at a perigee distance of approximately 0.13 lunar distances (50,000 km; 31,000 mi). Researchers, who discovered 2020 SO on September 17, 2020, are still unsure whether the object is a small near-Earth asteroid or an artificial object. The booster of Surveyor 2's Atlas-Centaur rocket, launched by NASA in 1966, is suspected by the Jet Propulsion Laboratory. (CNET)
- 28 November 2020 – Assassination of Iranian nuclear scientists
- Assassination of Mohsen Fakhrizadeh
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