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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.
Selected article
Gomphus clavatus, commonly known as pig's ears or the violet chanterelle, is an edible species of fungus in the genus Gomphus native to Eurasia and North America. The fruit body is vase- or fan-shaped with wavy edges to its rim, and grows up to 15–16 cm (6–6 1⁄4 in) wide and 17 cm (6 3⁄4 in) tall. The upper surface or cap is orangish-brown to lilac, while the lower spore-bearing surface, the hymenium, is covered in wrinkles and ridges rather than gills or pores, and is a distinctive purple color. Described by Jacob Christian Schäffer in 1774, G. clavatus has had several name changes and many alternative scientific names, having been classified in the genus Cantharellus (also called chanterelles), though it is not closely related to them.
Typically found in coniferous forests, G. clavatus is mycorrhizal, and is associated with tree species in a variety of coniferous genera, particularly spruces and firs. It is more common at elevations of greater than 2,000 ft (600 m), in moist, shady areas with plenty of leaf litter. Although widespread, G. clavatus has become rare in many parts of Europe and extinct in the British Isles. It has been placed on the national Red Lists of threatened fungi in 17 different European countries and is one of 33 species proposed for international conservation under the Bern Convention.
David Alexander Johnston (December 18, 1949 – May 18, 1980) was an American United States Geological Survey (USGS) volcanologist who was killed by the 1980 eruption of Mount St. Helens in the U.S. state of Washington. A principal scientist on the USGS monitoring team, Johnston was killed in the eruption while manning an observation post six miles (10 km) away on the morning of May 18, 1980. He was the first to report the eruption, transmitting "Vancouver! Vancouver! This is it!" before he was swept away by a lateral blast. Despite a thorough search, Johnston's body was never found, but state highway workers discovered remnants of his USGS trailer in 1993.
Johnston's career took him across the United States, where he studied the Augustine Volcano in Alaska, the San Juan volcanic field in Colorado, and long-extinct volcanoes in Michigan. Johnston was a meticulous and talented scientist, known for his analyses of volcanic gases and their relationship to eruptions. This, along with his enthusiasm and positive attitude, made him liked and respected by many co-workers. After his death, other scientists lauded his character, both verbally and in dedications and letters. Johnston felt scientists must do what is necessary, including taking risks, to help protect the public from natural disasters. His work, and that of fellow USGS scientists, convinced authorities to close Mount St. Helens to the public before the 1980 eruption. They maintained the closure despite heavy pressure to re-open the area; their work saved thousands of lives. His story became intertwined with the popular image of volcanic eruptions and their threat to society, and a part of volcanology's history. To date, Johnston, along with Harry Glicken, is one of two American volcanologists known to have died in a volcanic eruption.
Hurricane Isabel was the strongest Atlantic hurricane since Mitch, and the deadliest, costliest, and most intense hurricane in the 2003 Atlantic hurricane season. The ninth named storm, fifth hurricane, and second major hurricane of the season, Isabel formed near the Cape Verde Islands from a tropical wave on September 6, in the tropical Atlantic Ocean. It moved northwestward, and within an environment of light wind shear and warm waters, it steadily strengthened to reach peak winds of 165 mph (270 km/h) on September 11. After fluctuating in intensity for four days, during which it displayed annular characteristics, Isabel gradually weakened and made landfall on the Outer Banks of North Carolina, with winds of 105 mph (165 km/h) on September 18. Isabel quickly weakened over land and became extratropical over western Pennsylvania on the next day. On September 20, the extratropical remnants of Isabel were absorbed into another system over Eastern Canada.
In North Carolina, the storm surge from Isabel washed out a portion of Hatteras Island to form what was unofficially known as Isabel Inlet. Damage was greatest along the Outer Banks, where thousands of homes were damaged or even destroyed. The worst of the effects of Isabel occurred in Virginia, especially in the Hampton Roads area and along the shores of rivers as far west and north as Richmond and Baltimore. Virginia reported the most deaths and damage from the hurricane. About 64% of the damage and 69% of the deaths occurred in North Carolina and Virginia. Electric service was disrupted in areas of Virginia for several days, some more rural areas were without electricity for weeks, and local flooding caused thousands of dollars in damage.
The effects of Hurricane Georges in Louisiana included $30.1 million in damage and three deaths. Forming from a tropical wave over the Atlantic Ocean, Georges attained a peak intensity of 155 mph (250 km/h) on September 20, 1998. Over the following several days, the storm tracked through the Greater Antilles and later entered the Gulf of Mexico on September 28, the Category 2 storm made landfall in Mississippi before dissipating on October 1. Before landfall, about 500,000 residents in Louisiana evacuated from low-lying areas. The mayor of New Orleans declared a state of emergency to allow federal assistance into the state. After nearly 1.5 million people were urged to evacuate coastal areas, officials described the evacuation as "probably the largest [...] we have ever achieved".
Numerous homes located outside the levee system were flooded by the storm surge, and 85 fishing camps on the banks of Lake Pontchartrain were destroyed. An estimated 160,000 residences were left without power due to Georges and severe beach erosion took place due to the slow movement of the hurricane. Precipitation statewide peaked at 2.98 in (75.69 mm) in Bogalusa, and wind gusts reached 82 mph (132 km/h). In the wake of the hurricane, the Federal Emergency Management Agency (FEMA) opened 67 shelters throughout the state, and covered insurance claims totalling $14,150,532, including from Puerto Rico and Mississippi. The Clinton administration appropriated $56 million in disaster relief to regions in Louisiana for recovery from Tropical Storm Frances and Hurricane Georges.
The Eurasian treecreeper or common treecreeper (Certhia familiaris) is a small passerine bird also known in the British Isles, where it is the only living member of its genus, simply as treecreeper. It is similar to other treecreepers, and has a curved bill, patterned brown upperparts, whitish underparts, and long stiff tail feathers which help it creep up tree trunks. It can be most easily distinguished from the similar short-toed treecreeper, which shares much of its European range, by its different song.
The Eurasian treecreeper has nine or more subspecies which breed in different parts of its range in the Palearctic. This species is found in woodlands of all kinds, but where it overlaps with the short-toed treecreeper in western Europe it is more likely to be found in coniferous forests or at higher altitudes. It nests in tree crevices or behind bark flakes, and favours introduced giant sequoia as nest sites where they are available. The female typically lays five or six pink-speckled white eggs in the lined nest, but eggs and chicks are vulnerable to attack by woodpeckers and mammals, including squirrels.
Enceladus /ɛnˈsɛlədəs/ is the sixth-largest moon of Saturn. It is about 500 kilometers (310 mi) in diameter, about a tenth of that of Saturn's largest moon, Titan. Enceladus is mostly covered by fresh, clean ice, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon only reaches −198 °C (−324 °F), far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide range of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrains.
Enceladus was discovered on August 28, 1789, by William Herschel, but little was known about it until the two Voyager spacecraft, Voyager 1 and Voyager 2, passed nearby in 1980 and 1981. In 2005, the Cassini spacecraft started multiple close flybys of Enceladus, revealing its surface and environment in greater detail. In particular, Cassini discovered water-rich plumes venting from the south polar region. Cryovolcanoes near the south pole shoot geyser-like jets of water vapor, molecular hydrogen, other volatiles, and solid material, including sodium chloride crystals and ice particles, into space, totaling about 200 kg (440 lb) per second. Over 100 geysers have been identified. Some of the water vapor falls back as "snow"; the rest escapes, and supplies most of the material making up Saturn's E ring. According to NASA scientists, the plumes are similar in composition to comets. In 2014, NASA reported that Cassini found evidence for a large south polar subsurface ocean of liquid water with a thickness of around 10 km (6 mi).
The Mount Cayley volcanic field is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the Cayley volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, the largest and most persistent volcano, located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.
Eruptions along the length of the field began between 1.6 and 5.3 million years ago. At least 23 eruptions have occurred throughout its eruptive history. This volcanic activity ranged from effusive to explosive, with magma compositions ranging from basaltic to rhyolitic. Because the Mount Cayley volcanic field has a high elevation and consists of a cluster of mostly high altitude, non-overlapping volcanoes, subglacial activity is likely to have occurred under less than 800 m (2,600 ft) of glacial ice. The style of this glaciation promoted meltwater escape during eruptions. The steep profile of the volcanic field and its subglacial landforms support this hypothesis. As a result, volcanic features in the field that interacted with glacial ice lack rocks that display evidence of abundant water during eruption, such as hyaloclastite and pillow lava.
Fires approach the Old Faithful Complex on September 7, 1988
The Yellowstone fires of 1988 collectively formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. Starting as many smaller individual fires, the flames quickly spread out of control due to drought conditions and increasing winds, combining into one large conflagration which burned for several months. The fires almost destroyed two major visitor destinations and, on September 8, 1988, the entire park closed to all non-emergency personnel for the first time in its history. Only the arrival of cool and moist weather in the late autumn brought the fires to an end. A total of 793,880 acres (3,213 km2), or 36 percent of the park was affected by the wildfires.
Thousands of firefighters fought the fires, assisted by dozens of helicopters and fixed-wing aircraft which were used for water and fire retardant drops. At the peak of the effort, more than 9,000 firefighters were assigned to the park. With fires raging throughout the Greater Yellowstone Ecosystem and other areas in the western United States, the staffing levels of the National Park Service and other land management agencies were inadequate for the situation; more than 4,000 U.S. military personnel were soon brought in to assist in wildfire suppression efforts. The firefighting effort cost $120 million ($260 million in 2020). Losses to structures were minimized by concentrating firefighting efforts near major visitor areas, keeping property damage down to $3 million ($6 million as of 2020). No firefighters died while fighting the Yellowstone fires, though there were two fire-related deaths outside the park.
Priestley by Ellen Sharples (1794)
Joseph Priestley FRS (/ˈpriːstli/; 24 March [O.S. 13 March] 1733 – 6 February 1804) was an English chemist, natural philosopher, separatist theologian, grammarian, multi-subject educator, and liberal political theorist who published over 150 works. He has historically been credited with the discovery of oxygen, having isolated it in its gaseous state, although Carl Wilhelm Scheele and Antoine Lavoisier also have strong claims to the discovery, Scheele having discovered it in 1772, two years before Priestley.
During his lifetime, Priestley's considerable scientific reputation rested on his invention of carbonated water, his writings on electricity, and his discovery of several "airs" (gases), the most famous being what Priestley dubbed "dephlogisticated air" (oxygen). However, Priestley's determination to defend phlogiston theory and to reject what would become the chemical revolution eventually left him isolated within the scientific community.
Morchella rufobrunnea, commonly known as the blushing morel, is a species of ascomycete fungus in the family Morchellaceae. A choice edible species, the fungus was originally described as new to science in 1998 by mycologists Gastón Guzmán and Fidel Tapia from collections made in Veracruz, Mexico. Its distribution was later revealed to be far more widespread after several DNA studies suggested that it is common in the West Coast of the United States, Israel, Australia, and Cyprus.
M. rufobrunnea grows in disturbed soil or in woodchips used in landscaping, suggesting a saprophytic mode of nutrition. Reports from the Mediterranean under olive trees (Olea europaea), however, suggest the fungus may also be able to form facultative tree associations. Young fruit bodies have conical, grayish caps covered with pale ridges and dark pits; mature specimens are yellowish to ochraceous-buff. The surface of the fruit body often bruises brownish orange to pinkish where it has been touched, a characteristic for which the fungus is named, the New Latin rufobrunnea signifying "rufus brown". Mature fruit bodies grow to a height of 9.0–15.5 cm (3.5–6.1 in). M. rufobrunnea differs from other Morchella species by its urban or suburban habitat preferences, in the color and form of the fruit body, the lack of a sinus at the attachment of the cap with the stipe, the length of the pits on the surface, and the bruising reaction. A process to cultivate morels now known to be M. rufobrunnea was described and patented in the 1980s.- Tucana(The Toucan) is a constellation of stars in the southern sky, named after the toucan, a South American bird. It is one of twelve constellations conceived in the late sixteenth century by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Tucana first appeared on a 35-centimetre-diameter (14 in) celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and astronomer Nicolas Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Tucana, Grus, Phoenix and Pavo are collectively known as the "Southern Birds".
Tucana is not a prominent constellation as all of its stars are third magnitude or fainter; the brightest is Alpha Tucanae with an apparent visual magnitude of 2.87. Beta Tucanae is a star system with six member stars, while Kappa is a quadruple system. Five star systems have been found to have exoplanets to date. The constellation contains 47 Tucanae, one of the brightest globular clusters in the sky, and most of the Small Magellanic Cloud.
The Mascarene martin or Mascarene swallow (Phedina borbonica) is a passerine bird in the swallow family that breeds in Madagascar and in the Mascarene Islands. The nominate subspecies occurs on Mauritius and Réunion and has never been found away from the Mascarene Islands, but the smaller Madagascan subspecies, P. b. madagascariensis, is migratory and has been recorded wintering in East Africa or wandering to other Indian Ocean islands.
The Mascarene martin is a small swallow that has grey-brown underparts becoming white on the throat and lower abdomen, dark grey-brown upperparts and a slightly forked tail. The underparts are heavily streaked with black. It nests in small colonies anywhere with suitably sheltered sites for constructing a nest, such as ledges, buildings, tunnels, caves or amongst rocks. The nest is a shallow cup of twigs and other plant material, and the normal clutch is two or three brown-spotted white eggs. The incubation and fledging times are unknown. The Mascarene martin has a heavy flight with slow wingbeats interspersed with glides, and frequently perches on wires. It feeds on insects in flight, often hunting low over the ground or vegetation. In eastern Africa, open habitats such as deforested areas are frequently used for hunting. A number of internal and external parasites have been detected in this species.
Hurricane Nora was only the third tropical cyclone on record to reach Arizona as a tropical storm, and one of the rare cyclones to make landfall in Baja California. Nora was the fourteenth named tropical cyclone and seventh hurricane of the 1997 Pacific hurricane season. The September storm formed off the Pacific coast of Mexico, and aided by waters warmed by the 1997–98 El Niño event, eventually peaked at Category 4 intensity on the Saffir–Simpson hurricane scale.
Nora took an unusual path, making landfall twice as a hurricane in the Baja California Peninsula. Weakening quickly after landfall, its remnants lashed the Southwestern United States with tropical-storm-force winds, torrential rain and flooding. The storm was blamed for two direct casualties in Mexico, as well as substantial beach erosion on the Mexican coast, flash flooding in Baja California, and record precipitation in Arizona. It persisted far inland and eventually dissipated near the Arizona–Nevada border.
The black-necked grebe (Podiceps nigricollis), known in North America as the eared grebe, is a member of the grebe family of water birds. It was described in 1831 by Christian Ludwig Brehm. There are currently three accepted subspecies, including the nominate subspecies. Its breeding plumage features a distinctive ochre-coloured plumage which extends behind its eye and over its ear coverts. The rest of the upper parts, including the head, neck, and breast, are coloured black to blackish brown. The flanks are tawny rufous to maroon-chestnut, and the abdomen is white. When in its non-breeding plumage, this bird has greyish-black upper parts, including the top of the head and a vertical stripe on the back of the neck. The flanks are also greyish-black. The rest of the body is a white or whitish colour. The juvenile has more brown in its darker areas. The subspecies californicus can be distinguished from the nominate by the former's usually longer bill. The other subspecies, P. n. gurneyi, can be differentiated by its greyer head and upper parts and by its smaller size. P. n. gurneyi can also be told apart by its lack of a non-breeding plumage. This species is present in parts of Africa, Eurasia, and the Americas.
The black-necked grebe uses multiple foraging techniques. Insects, which make up the majority of this bird's diet, are caught either on the surface of the water or when they are in flight. It occasionally practices foliage gleaning. This grebe dives to catch crustaceans, molluscs, tadpoles, and small frogs and fish. When moulting at saline lakes, this bird feeds mostly on brine shrimp. The black-necked grebe makes a floating cup nest on an open lake. The nest cup is covered with a disc. This nest is located both in colonies and by itself. During the breeding season, which varies depending on location, this species will lay one (sometimes two) clutch of three to four eggs. The number of eggs is sometimes larger due to conspecific brood parasitism. After a 21-day incubation period, the eggs hatch, and then the nest is deserted. After about 10 days, the parents split up the chicks between themselves. After this, the chicks become independent in about 10 days, and fledge in about three weeks.
Hurricane Debbie was a moderate tropical cyclone which had significant impacts in Ireland as an extratropical cyclone. The fourth named storm of the 1961 Atlantic hurricane season, Debbie originated from a well-defined tropical disturbance that was first identified in late August over Central Africa. Tracking generally westward, the system moved off the coast of Senegal on September 5 into the Atlantic Ocean. By this time, it was estimated to have become a tropical depression, but forecasters did not issue advisories on the system until two days later. Late on September 6, Debbie passed through the southern Cape Verde Islands as a moderate tropical storm, resulting in a plane crash that killed 60 people in the islands. Once clear of the islands, data on the storm became sparse, and the status of Debbie was uncertain over the following several days as it tracked west-northwestward and later northward. It was not until a commercial airliner intercepted the storm on September 10 that its location became certain. The following day, Debbie intensified and reached its peak intensity as a Category 1 hurricane on the Saffir–Simpson hurricane scale, with maximum winds of 90 mph (150 km/h).
Maintaining its peak intensity for almost a day, the hurricane gradually slowed its forward motion and weakened. By September 13, Debbie's motion became influenced by the Westerlies, causing the system to accelerate east-northeastward. The system passed over the western Azores as an extratropical cyclone bearing hurricane-force winds on September 15. The system subsequently deepened as it neared Ireland, skirting the coast of Western Ireland on September 16. The remnants of the storm later weakened and turned eastward, striking Norway and Russia, before dissipating on September 19.
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Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. The effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of photographic developer fluid. They hoped to speed up the development process. Instead, they noticed tiny dots on the film after developing, and realized that the bubbles in the fluid were emitting light with the ultrasound turned on. It was too difficult to analyze the effect in early experiments because of the complex environment of a large number of short-lived bubbles. (This experiment is also ascribed to N. Marinesco and J.J. Trillat in 1933).
Sonoluminescence may or may not occur whenever a sound wave of sufficient intensity induces a gaseous cavity within a liquid to quickly collapse. This cavity may take the form of a pre-existing bubble, or may be generated through a process known as cavitation. Sonoluminescence in the laboratory can be made to be stable, so that a single bubble will expand and collapse over and over again in a periodic fashion, emitting a burst of light each time it collapses.
Selected biography
From the mid-1950s, he worked extensively in immunology and was a major contributor to the theory of clonal selection, which explains how lymphocytes target antigens for destruction. Burnet and Peter Medawar were co-recipients of the 1960 Nobel Prize in Physiology or Medicine for demonstrating acquired immune tolerance. This research provided the experimental basis for inducing immune tolerance, the platform for developing methods of transplanting solid organs.
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'?
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