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Scrubber | Scrubber systems ( aka Chemical Scrubbers , Gas Scrubbers ) are a diverse group of air pollution control devices that can be used to remove some particulates and/or gases from industrial exhaust streams . The first air scrubber was designed to remove carbon dioxide from the air of an early submarine , the Ictineo I , a role for which they continue to be used till today . Traditionally , the term `` scrubber '' has referred to pollution control devices that use liquid to wash unwanted pollutants from a gas stream . Recently , the term has also been used to describe systems that inject a dry reagent or slurry into a dirty exhaust stream to `` wash out '' acid gases . Scrubbers are one of the primary devices that control gaseous emissions , especially acid gases . Scrubbers can also be used for heat recovery from hot gases by flue-gas condensation . They are also used for the high flows in solar , PV , or LED processes . There are several methods to remove toxic or corrosive compounds from exhaust gas and neutralize it . |
Scientific_dissent | Scientific dissent is dissent from scientific consensus . Disagreements can be useful for finding problems in underlying assumptions , methodologies , and reasoning , as well as for generating and testing new ways of tackling the unknown . In modern times , with the increased role of science on the society and the politicization of science , a new aspect gained prominence : effects of scientific dissent on public policies . Scientific dissent is distinct from denialism , which is a deliberate rejection of scientific consensus usually for commercial or ideological reasons . |
Sea_ice_thickness | Sea ice thickness spatial extent , and open water within ice packs can vary rapidly in response to weather and climate . Sea ice concentration are measured by satellites , with the Special Sensor Microwave Imager / Sounder ( SSMIS ) , and the European Space Agency 's Cryosat-2 satellite to map the thickness and shape of the Earth 's polar ice cover . The sea ice volume is calculated with the Pan-Arctic Ice Ocean Modeling and Assimilation System ( PIOMAS ) , which blends satellite-observed data , such as sea ice concentrations into model calculations to estimate sea ice thickness and volume . Sea ice thickness determines a number of important fluxes such as heat flux between the air and ocean surface -- see below -- as well as salt and fresh water fluxes between the ocean since saline water ejects much of its salt content when frozen -- see sea ice growth processes . It is also important for navigators on icebreakers since there is an upper limit to the thickness of ice any ship can sail through . |
Secretary_of_State_for_Energy_and_Climate_Change | Her Majesty 's Principal Secretary of State for Energy and Climate Change was a British government cabinet position from 2008 to 2016 . The Department for Energy and Climate Change was created on 3 October 2008 when former Prime Minister Gordon Brown reshuffled his Cabinet . The Energy and Climate Change Secretary revived the earlier post of the Secretary of State for Energy as head of the Department of Energy , existing from 1974 to 1992 . After which , the Department of Energy was merged into the Department of Trade and Industry under the Conservative government of Sir John Major in 1992 . Sixteen years later , and immediately prior to the creation of the new department , energy policy was the responsibility of the Department for Business , Enterprise and Regulatory Reform ( itself now a defunct government department , superseded by the Department for Business , Innovation and Skills ) . In 2010 , Lord Marland was made Parliamentary Under-Secretary of State . On 3 February 2012 , Chris Huhne resigned from the post after it was announced that he would be prosecuted for perverting the course of justice , in relation to accusations that he passed on speeding penalties to his ex-wife to avoid losing his own licence . The post was taken over by Ed Davey on the same day . The post was formed into the new Department for Business , Energy and Industrial Strategy in July 2016 . |
Siberian_Shelf | The Siberian Shelf , one of the Arctic Ocean coastal shelves ( such as the Milne Ice Shelf ) , is the largest continental shelf of the Earth , a part of the continental shelf of Russia . It extends from the continent of Eurasia in the general area of North Siberia ( hence the name ) into the Arctic Ocean . It stretches to 1500 km offshore . It is relatively shallow , with average depth of 100 m . A number of islands are within the shelf , including the Wrangel Island , Novaya Zemlya , and the New Siberian Islands . It is encompassed by the Kara Sea , Laptev Sea , and East Siberian Sea , and respectively subdivided into the Kara Shelf , the Laptov Shelf and the East Siberian Shelf . Eastwards it merges into the Chukchi Shelf ( of the Chukchi Sea ) shared by Eurasia and North America ( i.e. , by Russia and the United States ) . Westwards it merges into the Barents Shelf of the Barents Sea . Also , the New Siberian Islands and the New Siberian Rift Basin define the ` New Siberian Shelf . ' According to the split of the high Arctic by the Lomonosov mid-ocean ridge into the Eurasian Basin and Amerasian Basin , the Siberian Shelf is split between the Eurasian Shelf and the Amerasian Shelf . |
Scientific_theory | A scientific theory is an explanation of some aspect of the natural world that can , in accordance with the scientific method , be repeatedly tested , using a predefined protocol of observations and experiments . Established scientific theories have withstood rigorous scrutiny and are a comprehensive form of scientific knowledge . It is important to note that the definition of a `` scientific theory '' ( often ambiguously contracted to `` theory '' for the sake of brevity , including in this page ) as used in the disciplines of science is significantly different from the common vernacular usage of the word `` theory '' . Per NAS 2008 : `` The formal scientific definition of theory is quite different from the everyday meaning of the word . It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence . '' In everyday non-scientific speech , `` theory '' can imply that something is an unsubstantiated and speculative guess , conjecture , idea , or , hypothesis ; such a usage is the opposite of the word `` theory '' in science . These different usages are comparable to the differing , and often opposing , usages of the term `` prediction '' in science versus `` prediction '' in vernacular speech , denoting a mere hope . The strength of a scientific theory is related to the diversity of phenomena it can explain . As additional scientific evidence is gathered , a scientific theory may be rejected or modified if it does not fit the new empirical findings ; in such circumstances , a more accurate theory is then desired . In certain cases , the less-accurate unmodified scientific theory can still be treated as a theory if it is useful ( due to its sheer simplicity ) as an approximation under specific conditions ( e.g. , Newton 's laws of motion as an approximation to special relativity at velocities that are small relative to the speed of light ) . Scientific theories are testable and make falsifiable predictions . They describe the causal elements responsible for a particular natural phenomenon , and are used to explain and predict aspects of the physical universe or specific areas of inquiry ( e.g. , electricity , chemistry , astronomy ) . Scientists use theories as a foundation to gain further scientific knowledge , as well as to accomplish goals such as inventing technology or curing disease . As with other forms of scientific knowledge , scientific theories are both deductive and inductive in nature and aim for predictive power and explanatory capability . Paleontologist , evolutionary biologist , and science historian Stephen Jay Gould said , `` ... facts and theories are different things , not rungs in a hierarchy of increasing certainty . Facts are the world ′ s data . Theories are structures of ideas that explain and interpret facts . '' |
Shift_work | Shift work is an employment practice designed to make use of , or provide service across , all 24 hours of the clock each day of the week ( often abbreviated as 24/7 ) . The practice typically sees the day divided into shifts , set periods of time during which different groups of workers perform their duties . The term `` shift work '' includes both long-term night shifts and work schedules in which employees change or rotate shifts . In medicine and epidemiology , shift work is considered a risk factor for some health problems in some individuals , as disruption to circadian rhythms may increase the probability of developing cardiovascular disease , cognitive impairment , diabetes , and obesity , among other conditions . Shift work can also contribute to strain in marital , family , and personal relationships . |
Seismic_risk | Seismic risk refers to the risk of damage from earthquake to a building , system , or other entity . Seismic risk has been defined , for most management purposes , as the potential economic , social and environmental consequences of hazardous events that may occur in a specified period of time . A building located in a region of high seismic hazard is at lower risk if it is built to sound seismic engineering principles . On the other hand , a building located in a region with a history of minor seismicity , in a brick building located on fill subject to liquifaction can be as high or higher risk . A special subset is urban seismic risk which looks at the specific issues of cities . Risk determination and emergency response can be also be determined through the use of an Earthquake scenario . |
Solar_Renewable_Energy_Certificate | Solar Renewable Energy Certificates ( SRECs ) or Solar Renewable Energy Credits are a form of Renewable Energy Certificate or `` Green tag '' existing in the United States of America . SRECs exist in states that have Renewable Portfolio Standard ( RPS ) legislation with specific requirements for solar energy , usually referred to as a `` solar carve-out '' . The additional income received from selling SRECs increases the economic value of a solar investment and assists with the financing of solar technology . In conjunction with state and federal incentives , solar system owners can recover their investment in solar by selling their SRECs through spot market sales or long-term sales , both described below . |
Solar_cycle_(calendar) | The solar cycle is a 28-year cycle of the Julian calendar with respect to the week . It occurs because leap years occur every 4 years and there are 7 possible days to start a leap year , making a 28-year sequence . This cycle also occurs in the Gregorian calendar , but it is interrupted by years such as 1800 , 1900 , 2100 , 2200 , 2300 and 2500 , which are divisible by four but which are common years . This interruption has the effect of skipping 16 years of the solar cycle between February 28 and March 1 . Because the Gregorian cycle of 400 years has exactly 146,097 days , i.e. exactly 20,871 weeks , one can say that the Gregorian so-called solar cycle lasts 400 years . Calendar years are usually marked by Dominical letters indicating the first Sunday in a new year , thus the term solar cycle can also refer to a repeating sequence of Dominical letters . Unless a year is not a leap year due to Gregorian exceptions , a sequence of calendars is reused every 28 years . The name solar cycle comes from Sunday , the traditional first day of the week . |
Species | In biology , a species ( abbreviated sp. , with the plural form species abbreviated spp . ) is the basic unit of biological classification and a taxonomic rank . A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring , typically by sexual reproduction . While this definition is often adequate , looked at more closely it is problematic . For example , with hybridisation , in a species complex of hundreds of similar microspecies , or in a ring species , the boundaries between closely related species become unclear . Other ways of defining species include similarity of DNA , morphology , or ecological niche . All species are given a two-part name , a `` binomial '' . The first part of a binomial is the genus to which the species belongs . The second part is called the specific name or the specific epithet ( in botany , also sometimes in zoology ) . For example , Boa constrictor is one of four species of the Boa genus . Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy , the great chain of being . In the 19th century , biologists grasped that species could evolve given sufficient time . Charles Darwin 's 1859 book The Origin of Species explained how species could arise by natural selection . Genes can sometimes be exchanged between species by horizontal gene transfer ; and species may become extinct for a variety of reasons . |
Space_Shuttle_Columbia_disaster | On February 1 , 2003 , the Space Shuttle Columbia disintegrated upon reentering Earth 's atmosphere , killing all seven crew members . The disaster was the second tragedy in the Space Shuttle program after Space Shuttle Challenger in 1986 , which broke apart and killed the seven-member crew 73 seconds after liftoff . During the launch of STS-107 , Columbia '' 's 28th mission , a piece of foam insulation broke off from the Space Shuttle external tank and struck the left wing of the orbiter . A few previous shuttle launches had seen damage ranging from minor to major from foam shedding , but some engineers suspected that the damage to Columbia was more serious . NASA managers limited the investigation , reasoning that the crew could not have fixed the problem if it had been confirmed . When Columbia '' re-entered the atmosphere of Earth , the damage allowed hot atmospheric gases to penetrate and destroy the internal wing structure , which caused the spacecraft to become unstable and break apart . After the disaster , Space Shuttle flight operations were suspended for more than two years , as they had been after the Challenger disaster . Construction of the International Space Station ( ISS ) was put on hold ; the station relied entirely on the Russian Roscosmos State Corporation for resupply for 29 months until Shuttle flights resumed with STS-114 and 41 months for crew rotation until STS-121 . Several technical and organizational changes were made , including adding a thorough on-orbit inspection to determine how well the shuttle 's thermal protection system had endured the ascent , and keeping a designated rescue mission ready in case irreparable damage was found . Except for one final mission to repair the Hubble Space Telescope , subsequent shuttle missions were flown only to the ISS so that the crew could use it as a haven in case damage to the orbiter prevented safe reentry . |
Solar_tower_(astronomy) | A solar tower , in the context of astronomy , is a structure used to support equipment for studying the sun , and is typically part of solar telescope designs . Generically , the term solar tower has many more uses especially for a type of power production using Earth 's Sun . Solar tower observatories are also called vacuum tower telescopes . Solar towers are used to raise the observation equipment above the atmospheric disturbances caused by solar heating of the ground and the radiation of the heat into the atmosphere . Traditional observatories do not have to be placed high above ground level , as they do most of their observation at night , when ground radiation is at a minimum . The horizontal Snow solar observatory was built on Mount Wilson in 1904 . It was soon found that heat radiation was disrupting observations . Almost as soon as the Snow Observatory opened , plans were started for a 60 ft tower that opened in 1908 followed by a 150 ft tower in 1912 . The 60 ft tower is currently used to study helioseismology , while the 150 ft tower is active in UCLA 's Solar Cycle Program . The term has also been used to refer to other structures used for experimental purposes , such as the Solar Tower Atmospheric Cherenkov Effect Experiment ( STACEE ) , which is being used to study Cherenkov radiation , and the Weizmann Institute solar power tower . |
Solar_eclipse_of_February_26,_1979 | In astronomy , a total solar eclipse occurred on February 26 , 1979 . A solar eclipse occurs when the Moon passes between Earth and the Sun , thereby totally or partly obscuring the image of the Sun for a viewer on Earth . A total solar eclipse occurs when the Moon 's apparent diameter is larger than the Sun 's , blocking all direct sunlight , turning day into darkness . Totality occurs in a narrow path across Earth 's surface , with the partial solar eclipse visible over a surrounding region thousands of kilometres wide . The central shadow of the moon passed through the northwestern U.S. states of Washington , Oregon , Idaho , Montana ( where totality covered almost the entire state ) , the north-central state of North Dakota , parts of the Canadian provinces of Saskatchewan , Manitoba , Ontario , Quebec , and what is now the Canadian Territory of Nunavut , and Greenland . |
Small_Business_Liability_Relief_and_Brownfields_Revitalization_Act | The Small Business Liability Relief and Brownfields Revitalization Act ( Pub . L.No . 107-118 , 115 stat . 2356 , `` the Brownfields Law '' ) was signed into law by President George W. Bush on January 11 , 2002 . Brownfields are defined as , `` A former industrial or commercial site where future use is affected by real or perceived environmental contamination . '' The Brownfields Law amended the Comprehensive Environmental Response , Compensation , and Liability Act ( CERCLA or Superfund ) by providing funds to assess and clean up brownfields , clarifying CERCLA liability protections , and providing funds to enhance state and tribal response programs . Other related laws and regulations impact brownfields cleanup and reuse through financial incentives and regulatory requirements . |
Socialism_in_Canada | Socialism in Canada has a long history and is , along with conservatism and liberalism , a major political force in Canada . |
Space_Shuttle | The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration ( NASA ) , as part of the Space Shuttle program . Its official program name was Space Transportation System ( STS ) , taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development . The first of four orbital test flights occurred in 1981 , leading to operational flights beginning in 1982 . Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011 , launched from the Kennedy Space Center ( KSC ) in Florida . Operational missions launched numerous satellites , interplanetary probes , and the Hubble Space Telescope ( HST ) ; conducted science experiments in orbit ; and participated in construction and servicing of the International Space Station . The Shuttle fleet 's total mission time was 1322 days , 19 hours , 21 minutes and 23 seconds . Shuttle components included the Orbiter Vehicle ( OV ) , a pair of recoverable solid rocket boosters ( SRBs ) , and the expendable external tank ( ET ) containing liquid hydrogen and liquid oxygen . The Shuttle was launched vertically , like a conventional rocket , with the two SRBs operating in parallel with the OV 's three main engines , which were fueled from the ET . The SRBs were jettisoned before the vehicle reached orbit , and the ET was jettisoned just before orbit insertion , which used the orbiter 's two Orbital Maneuvering System ( OMS ) engines . At the conclusion of the mission , the orbiter fired its OMS to de-orbit and re-enter the atmosphere . The orbiter then glided as a spaceplane to a runway landing , usually to the Shuttle Landing Facility at Kennedy Space Center , Florida or Rogers Dry Lake in Edwards Air Force Base , California . After landing at Edwards , the orbiter was flown back to the KSC on the Shuttle Carrier Aircraft , a specially modified version of the Boeing 747 . The first orbiter , Enterprise , was built in 1976 , used in Approach and Landing Tests and had no orbital capability . Four fully operational orbiters were initially built : Columbia , Challenger , Discovery , and Atlantis . Of these , two were lost in mission accidents : Challenger in 1986 and Columbia in 2003 , with a total of fourteen astronauts killed . A fifth operational ( and sixth in total ) orbiter , Endeavour , was built in 1991 to replace Challenger . The Space Shuttle was retired from service upon the conclusion of Atlantiss final flight on July 21 , 2011 . |
Solar_power | Solar power is the conversion of energy from sunlight into electricity , either directly using photovoltaics ( PV ) , or indirectly using concentrated solar power . Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam . Photovoltaic cells convert light into an electric current using the photovoltaic effect . Photovoltaics were initially solely used as a source of electricity for small and medium-sized applications , from the calculator powered by a single solar cell to remote homes powered by an off-grid rooftop PV system . Commercial concentrated solar power plants were first developed in the 1980s . The 392 MW Ivanpah installation is the largest concentrating solar power plant in the world , located in the Mojave Desert of California . As the cost of solar electricity has fallen , the number of grid-connected solar PV systems has grown into the millions and utility-scale solar power stations with hundreds of megawatts are being built . Solar PV is rapidly becoming an inexpensive , low-carbon technology to harness renewable energy from the Sun . The current largest photovoltaic power station in the world is the 850 MW Longyangxia Dam Solar Park , in Qinghai , China . The International Energy Agency projected in 2014 that under its `` high renewables '' scenario , by 2050 , solar photovoltaics and concentrated solar power would contribute about 16 and 11 percent , respectively , of the worldwide electricity consumption , and solar would be the world 's largest source of electricity . Most solar installations would be in China and India . Currently , as of 2016 , solar power provides just 1 % of total worldwide electricity production but growing 33 % per annum . |
Slippery_slope | A slippery slope argument ( SSA ) , in logic , critical thinking , political rhetoric , and caselaw , is a consequentialist logical device in which a party asserts that a relatively small first step leads to a chain of related events culminating in some significant ( usually negative ) effect , much like an object given a small push over the edge of a slope sliding all the way to the bottom . As such , the core of the slippery slope argument is that a specific decision under debate is likely to result in unintended consequences . The strength of such an argument depends on the warrant , i.e. whether or not one can demonstrate a process that leads to the significant effect . This type of argument is sometimes used as a form of fear mongering , in which the probable consequences of a given action are exaggerated in an attempt to scare the audience . The fallacious sense of `` slippery slope '' is often used synonymously with continuum fallacy , in that it ignores the possibility of middle ground and assumes a discrete transition from category A to category B . In a non-fallacious sense , including use as a legal principle , a middle-ground possibility is acknowledged , and reasoning is provided for the likelihood of the predicted outcome . Other idioms for the slippery slope argument are the thin end/edge of the wedge and the camel 's nose in the tent . |
Singularity_(climate) | A singularity is a weather phenomenon likely to occur with reasonable regularity around a specific approximate calendar date , outside of more general seasonal weather patterns ( e.g. , that May Day is usually warmer than New Year 's Day in northern locales ) . The existence of singularities is disputed , some considering them due to seeing patterns in noise and statistical artifacts from small samples . In North America , the most significant purported singularities are January thaw ( warmer weather around January 25 ) and Indian summer ( warmer weather in mid-autumn ) . More fanciful ones include the British tradition that rain on St. Swithun 's Day ( 15 July ) will be followed by forty days and nights of rain , and similar folk beliefs around groundhog day . |
Solar_cycle | The solar cycle or solar magnetic activity cycle is the nearly periodic 11-year change in the Sun 's activity ( including changes in the levels of solar radiation and ejection of solar material ) and appearance ( changes in the number and size of sunspots , flares , and other manifestations ) . They have been observed ( by changes in the sun 's appearance and by changes seen on Earth , such as auroras ) for centuries . The changes on the sun cause effects in space , in the atmosphere , and on Earth 's surface . While it is the dominant variable in solar activity , aperiodic fluctuations also occur . |
Solar_gain | Solar gain ( also known as solar heat gain or passive solar gain ) refers to the increase in temperature ( heat gain ) in a space , object or structure that results from solar radiation . The amount of solar gain increases with the strength of the sunlight , and with the ability of any intervening material to transmit or resist the radiation . Objects struck by sunlight absorb the short-wave radiation from the light and reradiate the heat at longer infrared wavelengths . Certain materials and substances , such as glass , are more transparent to the shorter wavelengths than the longer ; when the sun shines through such materials , the net result is an increase in temperature -- solar gain . This effect , the greenhouse effect , so called due to the solar gain that is experienced behind the glass of a greenhouse , has since become well known in the context of global warming . |
Solar_updraft_tower | The solar updraft tower ( SUT ) is a renewable-energy power plant for generating electricity from low temperature solar heat . Sunshine heats the air beneath a very wide greenhouse-like roofed collector structure surrounding the central base of a very tall chimney tower . The resulting convection causes a hot air updraft in the tower by the chimney effect . This airflow drives wind turbines placed in the chimney updraft or around the chimney base to produce electricity . Plans for scaled-up versions of demonstration models will allow significant power generation , and may allow development of other applications , such as water extraction or distillation , and agriculture or horticulture . Commercial investment may have been discouraged by the high initial cost of building a very large novel structure , the large land area required and by the risk of investment , however , there appears to be a renewed interest in solar updraft towers especially in sunny remote areas . A few prototypes have recently been constructed and projects are being proposed for parts of Africa , USA and Australia . An important fact to consider is that solar updraft towers appear to be the only renewable energy technology that can generate electricity from low temperature heat . Functional or mechanical feasibility is not so much an issue now as capitalisation . A comprehensive review of theoretical and experimental aspects of the solar updraft tower power plant ( SUTPP ) development is available , with a recommendation for commercial development . A popular update with interview of an informed engineering proponent has been published in National Geographic in 2014 . |
South_Magnetic_Pole | The South Magnetic Pole is the wandering point on the Earth 's Southern Hemisphere where the geomagnetic field lines are directed vertically upwards . It should not be confused with the South Geomagnetic Pole described later . For historical reasons , the `` end '' of a freely hanging magnet that points ( roughly ) north is itself called the `` north pole '' of the magnet , and the other end , pointing south , is called the magnet 's `` south pole '' . Because opposite poles attract , the Earth 's South Magnetic Pole is physically actually a magnetic north pole ( see also ) . The South Magnetic Pole is constantly shifting due to changes in the Earth 's magnetic field . As of 2005 it was calculated to lie at , placing it off the coast of Antarctica , between Adelie Land and Wilkes Land . In 2015 it lay at ( est ) . That point lies outside the Antarctic Circle . Due to polar drift , the pole is moving northwest by about 10 to 15 kilometers per year . Its current distance from the actual Geographic South Pole is approximately 2860 km . The nearest permanent science station is Dumont d'Urville Station . Wilkes Land contains a large gravitational mass concentration . -RCB- | | ( 2004 est ) | | ( 2007 ) | | ( 2015 ) | - | South Magnetic Pole | | ( 1998 ) | | ( 2004 est ) | | ( 2007 ) | | ( 2015 ) | -RCB- |
Spain | Spain ( España -LSB- esˈpaɲa -RSB- ) , officially the Kingdom of Spain ( -LSB- Reino de España , links = no -RSB- ) , is a sovereign state located on the Iberian Peninsula in southwestern Europe , with two large archipelagoes , the Balearic Islands in the Mediterranean Sea and the Canary Islands off the North African Atlantic coast , two cities Ceuta and Melilla in the North African mainland and several small islands in the Alboran Sea near the Moroccan coast . Its mainland is bordered to the south and east by the Mediterranean Sea except for a small land boundary with Gibraltar ; to the north and northeast by France , Andorra , and the Bay of Biscay ; and to the west and northwest by Portugal and the Atlantic Ocean . It is the only European country to have a border with an African country ( Morocco ) and its African territory accounts for nearly 5 % of its population , mostly in the Canary Islands but also in Ceuta and Melilla . With an area of 505990 km2 , Spain is the largest country in Southern Europe , the second largest country in Western Europe and the European Union , and the fourth largest country in the European continent . By population , Spain is the sixth largest in Europe and the fifth in the European Union . Spain 's capital and largest city is Madrid ; other major urban areas include Barcelona , Valencia , Seville , Bilbao and Málaga . Modern humans first arrived in the Iberian Peninsula around 35,000 years ago . Iberian cultures along with ancient Phoenician , Greek and Carthaginian settlements developed on the peninsula until it came under Roman rule around 200 BCE , after which the region was named Hispania , based on the earlier Phoenician name Span or Spania . In the Middle Ages , the area was conquered by Germanic tribes and later by the Moors . Spain emerged as a unified country in the 15th century , following the marriage of the Catholic Monarchs and the completion of the eight centuries-long reconquest , or Reconquista from the Moors in 1492 . In the early modern period , Spain became one of history 's first global colonial empires , leaving a vast cultural and linguistic legacy that includes over 500 million Spanish speakers , making Spanish the world 's second most spoken first language , after Mandarin Chinese . Spain is a democracy organised in the form of a parliamentary government under a constitutional monarchy . It is a middle power and a major developed country with the world 's fourteenth largest economy by nominal GDP and sixteenth largest by purchasing power parity . It is a member of the United Nations ( UN ) , the European Union ( EU ) , the Eurozone , the Council of Europe ( CoE ) , the Organization of Ibero-American States ( OEI ) , the North Atlantic Treaty Organization ( NATO ) , the Organisation for Economic Co-operation and Development ( OECD ) , the World Trade Organization ( WTO ) and many other international organisations . |
Space_exploration | Space exploration is the ongoing discovery and exploration of celestial structures in outer space by means of continuously evolving and growing space technology . While the study of space is carried out mainly by astronomers with telescopes , the physical exploration of space is conducted both by unmanned robotic space probes and human spaceflight . While the observation of objects in space , known as astronomy , predates reliable recorded history , it was the development of large and relatively efficient rockets during the mid-twentieth century that allowed physical space exploration to become a reality . Common rationales for exploring space include advancing scientific research , national prestige , uniting different nations , ensuring the future survival of humanity , and developing military and strategic advantages against other countries . Space exploration has often been used as a proxy competition for geopolitical rivalries such as the Cold War . The early era of space exploration was driven by a `` Space Race '' between the Soviet Union and the United States . The launch of the first human-made object to orbit Earth , the Soviet Union 's Sputnik 1 , on 4 October 1957 , and the first Moon landing by the American Apollo 11 mission on 20 July 1969 are often taken as landmarks for this initial period . The Soviet Space Program achieved many of the first milestones , including the first living being in orbit in 1957 , the first human spaceflight ( Yuri Gagarin aboard Vostok 1 ) in 1961 , the first spacewalk ( by Aleksei Leonov ) on 18 March 1965 , the first automatic landing on another celestial body in 1966 , and the launch of the first space station ( Salyut 1 ) in 1971 . After the first 20 years of exploration , focus shifted from one-off flights to renewable hardware , such as the Space Shuttle program , and from competition to cooperation as with the International Space Station ( ISS ) . With the substantial completion of the ISS following STS-133 in March 2011 , plans for space exploration by the USA remain in flux . Constellation , a Bush Administration program for a return to the Moon by 2020 was judged inadequately funded and unrealistic by an expert review panel reporting in 2009 . The Obama Administration proposed a revision of Constellation in 2010 to focus on the development of the capability for crewed missions beyond low Earth orbit ( LEO ) , envisioning extending the operation of the ISS beyond 2020 , transferring the development of launch vehicles for human crews from NASA to the private sector , and developing technology to enable missions to beyond LEO , such as Earth -- Moon L1 , the Moon , Earth -- Sun L2 , near-Earth asteroids , and Phobos or Mars orbit . In the 2000s , the People 's Republic of China initiated a successful manned spaceflight program , while the European Union , Japan , and India have also planned future manned space missions . China , Russia , Japan , and India have advocated manned missions to the Moon during the 21st century , while the European Union has advocated manned missions to both the Moon and Mars during the 20th/21st century . From the 1990s onwards , private interests began promoting space tourism and then public space exploration of the Moon ( see Google Lunar X Prize ) . |
Spruce_broom_rust | Spruce broom rust or yellow witches ' broom rust is a fungal plant disease caused by the basidiomycete fungus known as Chrysomyxa arctosphyli . It occurs exclusively in North America , with the most concentrated outbreaks occurring in northern Arizona and southern Colorado on blue and Engelmann spruce , as well as in Alaska on black and white spruce . This disease alternates its life cycle between two hosts , with the spruce serving as the primary host and bearberry ( also known as kinnickinnick ) serving as the secondary or alternate host . The name for the disease comes from the distinctive `` witches broom '' , commonly yellow in color , which forms on the spruce after young needles have been infected . Management must be carried out through physical or mechanical methods , such as the pruning of brooms or the removal of the secondary host from the area , because no chemical control measures ( e.g. fungicides ) have yet been determined to be economically effective . Generally , spruce broom rust is seen as a mostly cosmetic issue , and it is very rarely the direct cause of tree death ; however , research has shown a reduction in overall productivity and health of infected trees , making it an important issue for logging and timber companies . |
Southern_Ocean | The Southern Ocean , also known as the Antarctic Ocean or the Austral Ocean , comprises the southernmost waters of the World Ocean , generally taken to be south of 60 ° S latitude and encircling Antarctica . As such , it is regarded as the fourth-largest of the five principal oceanic divisions : smaller than the Pacific , Atlantic , and Indian Oceans but larger than the Arctic Ocean . This ocean zone is where cold , northward flowing waters from the Antarctic mix with warmer subantarctic waters . By way of his voyages in the 1770s , Captain James Cook proved that waters encompassed the southern latitudes of the globe . Since then , geographers have disagreed on the Southern Ocean 's northern boundary or even existence , considering the waters part of the Pacific , Atlantic , and Indian Oceans , instead . This remains the current official policy of the International Hydrographic Organization ( IHO ) , since a 2000 revision of its definitions including the Southern Ocean as the waters south of the 60th parallel has not yet been adopted . Others regard the seasonally-fluctuating Antarctic Convergence as the natural boundary . |
Southern_Cone | Southern Cone ( Cono Sur , Cone Sul ) is a geographic region composed of the southernmost areas of South America , south of and around the Tropic of Capricorn . Traditionally , it covers Argentina , Chile and Uruguay , bounded on the west by the Pacific Ocean , and south to the junction between the Pacific and Atlantic Oceans , which is the continental area closest to Antarctica ( 1000 km ) . In terms of social and political geography , the Southern Cone comprises Argentina , Chile , Uruguay , part of Southern and Southeastern ( São Paulo ) Brazil and sometimes Paraguay . High life expectancy , the highest Human Development Index of Latin America , high standard of living , significant participation in the global markets and the emerging economy of its members make the Southern Cone the most prosperous macro-region in Latin America . |
Skepticism | Skepticism ( American English ) or scepticism ( British English ; see spelling differences ) is generally any questioning attitude or doubt towards one or more items of putative knowledge or belief . It is often directed at domains , such as morality ( moral skepticism ) , religion ( skepticism about the existence of God ) , or knowledge ( skepticism about the possibility of knowledge , or of certainty ) . Formally , skepticism as a topic occurs in the context of philosophy , particularly epistemology , although it can be applied to any topic such as politics , religion , and pseudoscience . Philosophical skepticism comes in various forms . Radical forms of skepticism deny that knowledge or rational belief is possible and urge us to suspend judgment on many or all controversial matters . More moderate forms of skepticism claim only that nothing can be known with certainty , or that we can know little or nothing about the `` big questions '' in life , such as whether God exists or whether there is an afterlife . Religious skepticism is `` doubt concerning basic religious principles ( such as immortality , providence , and revelation ) '' . Scientific skepticism concerns testing beliefs for reliability , by subjecting them to systematic investigation using the scientific method , to discover empirical evidence for them . |
Smog | Smog is a type of air pollutant . The word `` smog '' was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog , its opacity , and odour . The word was then intended to refer to what was sometimes known as pea soup fog , a familiar and serious problem in London from the 19th century to the mid 20th century . This kind of visible air pollution is composed of nitrogen oxides , sulfur oxides , ozone , smoke or particulates among others ( less visible pollutants include carbon monoxide , CFCs and radioactive sources ) . Human-made smog is derived from coal emissions , vehicular emissions , industrial emissions , forest and agricultural fires and photochemical reactions of these emissions . Modern smog , as found for example in Los Angeles , is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog . In certain other cities , such as Delhi , smog severity is often aggravated by stubble burning in neighboring agricultural areas . The atmospheric pollution levels of Los Angeles , Beijing , Delhi , Mexico City , Tehran and other cities are increased by inversion that traps pollution close to the ground . It is usually highly toxic to humans and can cause severe sickness , shortened life or death . |
Solar_eclipse_of_July_11,_1991 | A total solar eclipse occurred on July 11 , 1991 . A solar eclipse occurs when the Moon passes between Earth and the Sun , thereby totally or partly obscuring the image of the Sun for a viewer on Earth . A total solar eclipse occurs when the Moon 's apparent diameter is larger than the Sun 's , blocking all direct sunlight , turning day into darkness . Totality occurs in a narrow path across Earth 's surface , with the partial solar eclipse visible over a surrounding region thousands of kilometres wide . Totality began over the Pacific Ocean and Hawaii moving across Mexico , down through Central America and across South America ending over Brazil . It lasted for 6 minutes and 53 seconds at the point of maximum eclipse . There will not be a longer total eclipse until June 13 , 2132 . This eclipse was the most central total eclipse in 800 years , with a gamma of -.0041 . There will not be a more central eclipse for another 800 years . Its magnitude was also greater than any eclipse since the 6th century . |
Spider_bite | A spider bite , also known as arachnidism , is an injury resulting from the bite of a spider . The effects of most bites are not serious . Most bites result in mild symptoms around the area of the bite . Rarely they may produce a necrotic skin wound or severe pain . Most spiders do not cause bites that are of importance . For a bite to be significant , substantial envenomation is required . Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism . Symptoms may include : pain which may be at the bite or involve the chest and abdomen , sweating , muscle cramps and vomiting among others . Bites from the recluse spiders cause the condition loxoscelism , in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur . Headaches , vomiting and a mild fever may also occur . Other spiders that can cause significant bites include : the Australian funnel-web spider and South American wandering spider . Efforts to prevent bites include clearing clutter and the use of pesticides . Most spider bites are managed with supportive care such as nonsteroidal anti-inflammatory drugs ( including ibuprofen ) for pain and antihistamines for itchiness . Opioids may be used if the pain is severe . While an antivenom exists for black widow spider venom , it is associated with anaphylaxis and therefore not commonly used in the United States . Antivenom against funnel web spider venom improves outcomes . Surgery may be required to repair the area of injured skin from some recluse bites . Spider bites may be overdiagnosed or misdiagnosed . Historically a number of conditions were attributed to spider bites . In the Middle Ages a condition claimed to arise from spider bites was tarantism , where people danced wildly . While necrosis has been attributed to the bites of a number of spiders , good evidence only supports this for recluse spiders . |
Sky | The sky ( or celestial dome ) is everything that lies above the surface of the Earth , including the atmosphere and outer space . In the field of astronomy , the sky is also called the celestial sphere . This is viewed from Earth 's surface as an imaginary dome where the Sun , stars , planets , and the Moon are seen to be traveling . The celestial sphere is conventionally divided into regions called constellations . Usually , the term sky is used informally as the point of view from the Earth 's surface ; however , the meaning and usage can vary . In some cases , such as in discussing the weather , the sky refers to only the lower , more dense portions of the atmosphere . During daylight , the sky appears to be blue because air scatters blue sunlight more than it scatters red . At night , the sky appears to be a mostly dark surface or region scattered with stars . During the day , the Sun can be seen in the sky unless obscured by clouds . In the night sky ( and to some extent during the day ) the Moon , planets and stars are visible in the sky . Some of the natural phenomena seen in the sky are clouds , rainbows , and aurorae . Lightning and precipitation can also be seen in the sky during storms . Birds , insects , aircraft , and kites are often considered to fly in the sky . Due to human activities , smog during the day and light pollution during the night are often seen above large cities . |
Smallholding | A smallholding is a small farm . In third world countries , smallholdings are usually farms supporting a single family with a mixture of cash crops and subsistence farming . As a country becomes more affluent and farming practices become more efficient , smallholdings may persist as a legacy of historical land ownership practices . In more affluent societies , smallholdings may be valued primarily for the rural lifestyle that they provide for the owners , who often do not earn their livelihood from the farm . There are an estimated 500 million smallholder farms in the world , supporting almost 2 billion people . Today some companies try to include smallholdings into their value chain , providing seed , feed or fertilizer to improve production . Some say that this model shows benefits for both parties . |
Sputnik_(news_agency) | Sputnik ( -LSB- ˈsputʲnʲɪk -RSB- ; formerly The Voice of Russia ) is a news agency , news websites and radio broadcast service established by the Russian government-controlled news agency Rossiya Segodnya . Headquartered in Moscow , Sputnik has regional editorial offices in Washington , Cairo , Beijing , London and Edinburgh . It focuses on global politics and economics and is geared towards a non-Russian audience . Sputnik has been widely accused of bias , disinformation and being a Russian propaganda outlet . Sputnik currently operates news websites , featuring reporting and commentary , in over 30 languages including English , Spanish , Polish , Serbian , and several others . The websites also house over 800 hours of radio broadcasting material each day and its newswire service runs around the clock . Alongside its news content , Sputnik also produces photo essays , live streaming , infographics , and public opinion surveys . Sputnik News is a successor to Russian state-owned RIA Novosti 's international branch ( '' ... outside Russia our agency will be branded as Sputnik , which sounds familiar , warm , swift and romantic ... '' ) , which became defunct in 2013 . Whereas RIA Novosti 's output tended to emanate from a more concentrated base in Moscow , Sputnik 's content is drawn from a number of international bureaux . |
Space_Shuttle_Challenger_disaster | On January 28 , 1986 , the NASA shuttle orbiter mission STS-51-L and the tenth flight of Space Shuttle Challenger ( OV-99 ) broke apart 73 seconds into its flight , killing all seven crew members , which consisted of five NASA astronauts and two payload specialists . The spacecraft disintegrated over the Atlantic Ocean , off the coast of Cape Canaveral , Florida , at 11:39 EST ( 16:39 UTC ) . Disintegration of the vehicle began after an O-ring seal in its right solid rocket booster ( SRB ) failed at liftoff . The O-ring was not designed to fly under unusually cold conditions as in this launch . Its failure caused a breach in the SRB joint it sealed , allowing pressurized burning gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB aft field joint attachment hardware and external fuel tank . This led to the separation of the right-hand SRB 's aft field joint attachment and the structural failure of the external tank . Aerodynamic forces broke up the orbiter . The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation . The exact timing of the death of the crew is unknown ; several crew members are known to have survived the initial breakup of the spacecraft . The shuttle had no escape system , and the impact of the crew compartment with the ocean surface was too violent to be survivable . The disaster resulted in a 32-month hiatus in the shuttle program and the formation of the Rogers Commission , a special commission appointed by United States President Ronald Reagan to investigate the accident . The Rogers Commission found NASA 's organizational culture and decision-making processes had been key contributing factors to the accident , with the agency violating its own safety rules . NASA managers had known since 1977 that contractor Morton Thiokol 's design of the SRBs contained a potentially catastrophic flaw in the O-rings , but they had failed to address this problem properly . NASA managers also disregarded warnings ( an example of `` go fever '' ) from engineers about the dangers of launching posed by the low temperatures of that morning , and failed to adequately report these technical concerns to their superiors . As a result of the disaster , the Air Force decided to cancel its plans to use the Shuttle for classified military satellite launches from Vandenberg Air Force Base in California , deciding to use the Titan IV instead . Approximately 17 percent of Americans witnessed the launch live because of the presence of Payload Specialist Christa McAuliffe , who would have been the first teacher in space . Media coverage of the accident was extensive : one study reported that 85 percent of Americans surveyed had heard the news within an hour of the accident . The Challenger '' disaster has been used as a case study in many discussions of engineering safety and workplace ethics . |
Southern_Australia | The term Southern Australia is generally considered to include the states and territories of Australia of New South Wales , Victoria , Tasmania , the Australian Capital Territory and South Australia . The part of Western Australia south of latitude 26 ° south -- a definition widely used in law and state government policy -- is also usually included . Although it comprises about half of the total area of Australia , Southern Australia includes about three quarters of the Australian population , the two largest cities ( Sydney and Melbourne ) , the political capital ( Canberra ) , the main food growing areas and the main industrial centres . The area is also notable for its primarily temperate , mediterranean , alpine or arid environmental and climatic conditions which contrasts to the mainly tropical climate of Northern Australia . Southern Australia suffers from bushfires and wildfires . |
Soft_landing_(economics) | A soft landing in the business cycle is the process of an economy shifting from growth to slow-growth to potentially flat , as it approaches but avoids a recession . It is usually caused by government attempts to slow down inflation . The criteria for distinguishing between a hard and soft landing are numerous and subjective . The term was adapted to economics from its origins in the early days of flight , when it historically was the method of the landing of hot air balloons , by gradually reducing their buoyancy . It later also applied to aviation , gliders and spacecraft , as in the Lunar lander . In the United States , modern recessions and hard and soft landings follow from Federal Reserve tightening cycles , in which the Federal funds rate is increased over several consecutive moves . In modern times , the most notable , and possibly the only true soft landing in the most recent 16 business cycles occurred in the soft landing of 1994 , engineered by Federal Reserve Chairman Alan Greenspan through fine tuning of interest rates and the money supply . In addition to being a certain type of business cycle , a soft landing may also refer to a market segment or industry sector that is expected to slow down , but to not crash , while the wider economy may not experience such a slow down at that time . For example , a contemporary newspaper headline read : `` Soft landing forecast for house prices as rate hikes stem growth '' . As it stands , these forecasts have very little scientific value and there is not one single verifiable instance of a soft landing following an economic bubble . This is enforced by definition , as any potential bubble followed by a soft landing would , in retrospect , not be deemed a bubble . |
Solar_power_by_country | Many industrialized nations have installed significant solar power capacity into their electrical grids to supplement or provide an alternative to conventional energy sources while an increasing number of less developed nations have turned to solar to reduce dependence on expensive imported fuels . Long distance transmission allows remote renewable energy resources to displace fossil fuel consumption . Solar power plants use one of two technologies : Photovoltaic ( PV ) systems use solar panels , either on rooftops or in ground-mounted solar farms , converting sunlight directly into electric power . Concentrated solar power ( CSP , also known as `` concentrated solar thermal '' ) plants use solar thermal energy to make steam , that is thereafter converted into electricity by a turbine . Worldwide growth of photovoltaics is extremely dynamic and varies strongly by country . By the end of 2016 , cumulative photovoltaic capacity increased by more than 75 gigawatt ( GW ) and reached at least 303 GW , sufficient to supply 1.8 percent of the world 's total electricity consumption . The top installers of 2016 were China , the United States , and India . There are more than 24 countries around the world with a cumulative PV capacity of more than one gigawatt . Austria , the Chile , and South Africa , all crossed the one gigawatt-mark in 2016 . The available solar PV capacity in Honduras is now sufficient to supply 12.5 % of the nation 's electrical power while Italy , Germany and Greece can produce between 7 % and 8 % of their respective domestic electricity consumption . After an almost two decade long hiatus , deployment of CSP resumed in 2007 , with significant growth only in the most recent years . However , the design for several new projects is being changed to cheaper photovoltaics . Most operational CSP stations are located in Spain and the United States , while large solar farms using photovoltaics are being constructed in an expanding list of geographic regions . As of January 2017 , the largest solar power plants in the world are the 850 MW Longyangxia Dam Solar Park in China for PV and the 377 MW Ivanpah Solar Power Facility in the United States for CSP . Other large CSP facilities include the 354 megawatt ( MW ) Solar Energy Generating Systems power installation in the USA , Solnova Solar Power Station ( Spain , 150 MW ) , Andasol Solar Power Station ( Spain , 150 MW ) and the first part of Shams solar power station ( United Arab Emirates , 100 MW ) . |
Snowball_Earth | The Snowball Earth hypothesis proposes that Earth 's surface became entirely or nearly entirely frozen at least once , sometime earlier than 650 Mya ( million years ago ) . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical palaeolatitudes , and other enigmatic features in the geological record . Opponents of the hypothesis contest the implications of the geological evidence for global glaciation and the geophysical feasibility of an ice - or slush-covered ocean , and emphasize the difficulty of escaping an all-frozen condition . A number of unanswered questions remain , including whether the Earth was a full snowball , or a `` slushball '' with a thin equatorial band of open ( or seasonally open ) water . The snowball Earth episodes occurred before the sudden radiation of multicellular bioforms , known as the Cambrian explosion . The most recent snowball episode may have triggered the evolution of multicellularity . Another , much earlier and longer snowball episode , the Huronian glaciation , which occurred 2400 to 2100 Mya , may have been triggered by the first appearance of oxygen in the atmosphere , the `` Great Oxygenation Event . '' |
Solar_cycle_18 | Solar cycle 18 was the eighteenth solar cycle since 1755 , when extensive recording of solar sunspot activity began . The solar cycle lasted 10.2 years , beginning in February 1944 and ending in April 1954 . The maximum smoothed sunspot number ( SIDC formula ) observed during the solar cycle was 218.7 ( May 1947 ) , and the starting minimum was 12.9 . During the minimum transit from solar cycle 18 to 19 , there were a total of 446 days with no sunspots . Cycle 18 was characterized by `` giant '' sunspots . The recording of the 10.7 cm ( 2800 MHz ) solar radio flux began partway during this cycle , and values of the solar flux during this cycle turned out to be particularly high . |
Simulation_heuristic | The simulation heuristic is a psychological heuristic , or simplified mental strategy , according to which people determine the likelihood of an event based on how easy it is to picture the event mentally . Partially as a result , people experience more regret over outcomes that are easier to imagine , such as `` near misses '' . The simulation heuristic was first theorized by psychologists Daniel Kahneman and Amos Tversky as a specialized adaptation of the availability heuristic to explain counterfactual thinking and regret . However , it is not the same as the availability heuristic . Specifically the simulation heuristic is defined as `` how perceivers tend to substitute normal antecedent events for exceptional ones in psychologically ` undoing ' this specific outcome . '' Kahneman and Tversky also believed that people used this heuristic to understand and predict other 's behavior in certain circumstances and to answer questions involving counterfactual propositions . People , they believe , do this by mentally undoing events that have occurred and then running mental simulations of the events with the corresponding input values of the altered model . For example , a study was proposed that provided a group of participants with a situation describing two men who were delayed by half an hour in a traffic jam on the way to the airport . Both men were delayed enough that they both missed flights on which they were booked , one of them by half an hour and the second by only five minutes ( because his flight had been delayed for 25 minutes ) . The results showed that a greater number of participants thought that the second man would be more upset than the first man . Kahneman and Tversky argued that this difference could not be attributed to disappointment , because both had expected to miss their flights . They believed instead that the true explanation was that the students utilized the simulation heuristic and so it was easier for them to imagine minor alterations that would have enabled the second man to arrive in time for his flight than it was for them to devise the same alterations for the first man . |
Solar_power_in_Michigan | Solar power in Michigan has been growing in recent years due to new technological improvements and a variety of regulatory actions and financial incentives , particularly a 30 % federal tax credit , available for any size project . Although among the lowest U.S. states for solar irradiance , Michigan mostly lies farther south than Germany where solar power is heavily deployed . Michigan is expected to use 120 TWh per year in 2030 . To reach a 100 % solar electrical grid would require 2.4 % of Michigan 's land area to host 108 GW of installed capacity . According to the Michigan Public Service Commission , the state had an estimated 27 MW of solar capacity as of the end of 2014 . |
Sister_paper | A sister paper is one of two or more newspapers which share a common owner , but are published with different content , different names , and sometimes ( but not necessarily ) in different geographical areas . Such an arrangement can offer economies of scale because staff and infrastructure can be shared . Formerly independent papers can become sister papers , as when the Wall Street Journal and the New York Post were both purchased by News Corporation . Concerns have sometimes been raised about such media consolidation resulting in less diversity of ideas , less competition in the newspaper business , or unfair competition . Conversely , a single newspaper company can start several publications . By doing so , it can serve different markets , or different audiences in the same market , with less overhead than if the publications operated separately . |
Southern_California_Edison | Southern California Edison ( or SCE Corp ) , the largest subsidiary of Edison International , is the primary electricity supply company for much of Southern California , USA . It provides 14 million people with electricity across a service territory of approximately 50,000 square miles . However , the Los Angeles Department of Water and Power , San Diego Gas & Electric , Imperial Irrigation District , and some smaller municipal utilities serve substantial portions of the southern California territory . The northern part of the state is generally served by the Pacific Gas & Electric Company of San Francisco . Southern California Edison ( SCE ) still owns all of its electrical transmission facilities and equipment , but the deregulation of California 's electricity market in the late 1990s forced the company to sell many of its power plants , though some were probably sold by choice . In California , SCE retained only its hydroelectric plants , totaling about 1,200 MW , and its 75 % share of the 2,150-MW San Onofre Nuclear Generating Station , which has been shut down since January 2012 ; in June 2013 the company announced its intention to permanently close and decommission the nuclear plant . Also , SCE still owns about half of the 1,580-MW coal-fired Mohave Generating Station in Laughlin , Nevada , which supplied electricity to California , Nevada , and Arizona ; Mohave closed in December 2005 , amid concerns regarding water rights and coal supplies . The utility lost all of its natural gas-fired plants , which provided most of its electrical generation . The large , aging plants were bought by out-of-state companies such as Mirant and Reliant Energy , which allegedly used them to manipulate the California energy market . Southern California Edison 's power grid is linked to PG&E 's by the Path 26 wires that generally follow Interstate 5 over Tejon Pass . The interconnection takes place at a massive substation at Buttonwillow . PG&E 's and WAPA 's Path 15 and Path 66 , respectively , from Buttonwillow north eventually connect to BPA 's grid in the Pacific Northwest . There are several other interconnections with local and out-of-state utilities , such as Path 46 . In addition , SCE operates a regulated gas and water utility . SCE is the sole commercial provider of natural gas and fresh water service to Santa Catalina Island , including the city of Avalon , California . SCE operates the utilities under the names of Catalina Island Gas Company and Catalina Island Water Company . |
Space_station | A space station , also known as an orbital station or an orbital space station , is a spacecraft capable of supporting crewmembers , which is designed to remain in space ( most commonly as an artificial satellite in low Earth orbit ) for an extended period of time and for other spacecraft to dock . A space station is distinguished from other spacecraft used for human spaceflight by lack of major propulsion or landing systems . Instead , other vehicles transport people and cargo to and from the station . three space stations are in orbit : the International Space Station , which is permanently manned , China 's Tiangong-1 ( defunct ) and Tiangong-2 ( launched 15 September 2016 , not permanently manned ) . Previous stations include the Almaz and Salyut series , Skylab , and most recently Mir . Today 's space stations are research platforms , used to study the effects of long-term space flight on the human body as well as to provide platforms for greater number and length of scientific studies than available on other space vehicles . Each crew member stays aboard the station for weeks or months , but rarely more than a year . Since the ill-fated flight of Soyuz 11 to Salyut 1 , all manned spaceflight duration records have been set aboard space stations . The duration record for a single spaceflight is 437.7 days , set by Valeriy Polyakov aboard Mir from 1994 to 1995 . , four cosmonauts have completed single missions of over a year , all aboard Mir . Space stations have also been used for both military and civilian purposes . The last military-use space station was Salyut 5 , which was used by the Almaz program of the Soviet Union in 1976 and 1977 . |
Spring_fever | Spring fever is a term applied to various mood , physical , or behavioral changes , which may be experienced coinciding with the arrival of spring . It is not a medical term , and is not considered a disease or malfunction of the human body . The term `` spring fever '' is an auto-antonym ( a term with multiple and opposed meanings ) : On the one hand , the term may refer to an increase in energy , vitality , and sexual appetite , as well as a feeling of restlessness , associated with the end of winter . This concept may have a biological basis . A lift in mood with the arrival of spring , and longer periods of daylight , is often particularly strong in those suffering from seasonal affective disorder ( SAD ) , who experience lows or depression during the winter months . It is this sense that inspires the use of the term as a title for several works of literature and entertainment . On the other hand , the term may sometimes be used to describe an opposite effect of springtime lethargy or depression . |
Slack_water | Slack water , also known as ` the stand of the tide ' , is a short period in a body of tidal water when the water is completely unstressed , and there is no movement either way in the tidal stream , and which occurs before the direction of the tidal stream reverses . Slack water can be estimated using a tidal atlas or the tidal diamond information on a nautical chart . The time of slack water , particularly in constricted waters , does not occur at high and low water , and in certain areas , such as Primera Angostura , the ebb may run for up to three hours after the water level has started to rise , and the flood may run for three hours after the water has started to fall . Thornton Lecky , writing in 1884 , illustrates the phenomenon with an inland basin of infinite size , connected to the sea by a narrow mouth . Since the level of the basin is always at mean sea level , the flood in the mouth starts at half tide , and its velocity is at its greatest at the time of high water , with the strongest ebb occurring conversely at low water . |
Solar_eclipse_of_October_3,_2005 | An annular solar eclipse occurred on October 3 , 2005 with a magnitude of 0.958 . A solar eclipse occurs when the Moon passes between Earth and the Sun , thereby totally or partly obscuring the image of the Sun for a viewer on Earth . An annular solar eclipse occurs when the Moon 's apparent diameter is smaller than the Sun 's , blocking most of the Sun 's light and causing the Sun to look like an annulus ( ring ) . An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide . It was visible from a narrow corridor through the Iberian peninsula and Africa . A partial eclipse was seen from the much broader path of the Moon 's penumbra , including all of Europe , Africa and southwestern Asia . The path of the eclipse began in the North Atlantic ocean at 08:41 universal time ( UT ) . The antumbra reached Madrid , Spain at 08:56 UT , lasting four minutes and eleven seconds and 90 % of the Sun was covered by the Moon . The antumbra reached Algiers at 09:05 UT , then passed through Tunisia and Libya before heading southeast through Sudan , Kenya and Somalia . The shadow then moved out over the Indian Ocean until it terminated at sunset , 12:22 UT . The maximum eclipse duration occurred in central Sudan at 10:31:42 UT , where it lasted for 4m 31s when the Sun was 71 ° above the horizon . The theoretical maximum duration for a modern solar eclipse is 7 minutes , 32 seconds . The motion of the shadow was supersonic and it generated gravity waves that were detectable as disturbances in the ionosphere . These gravity waves originate in the thermosphere at an altitude of about 180 km . Because of the obscuration of solar radiation , the ionization level dropped by 70 % during the eclipse . The eclipse caused a 1 -- 1.4 K drop in the temperature of the ionosphere . |
Spruce | A spruce is a tree of the genus Picea -LSB- paɪˈsiːə -RSB- , a genus of about 35 species of coniferous evergreen trees in the family Pinaceae , found in the northern temperate and boreal ( taiga ) regions of the earth . Spruces are large trees , from about 20 -- 60 m ( about 60 -- 200 ft ) tall when mature , and can be distinguished by their whorled branches and conical form . The needles , or leaves , of spruce trees are attached singly to the branches in a spiral fashion , each needle on a small , peg-like structure . The needles are shed when 4 -- 10 years old , leaving the branches rough with the retained pegs ( an easy means of distinguishing them from other similar genera , where the branches are fairly smooth ) . Spruces are used as food plants by the larvae of some Lepidoptera ( moth and butterfly ) species . They are also used by the larvae of gall adelgids ( Adelges species ) . In the mountains of western Sweden , scientists have found a Norway spruce tree , nicknamed Old Tjikko , which by reproducing through layering , has reached an age of 9,550 years and is claimed to be the world 's oldest known living tree . |
Snow_in_Florida | It is very rare for snow to fall in the U.S. state of Florida , especially in the central and southern portions of the state . With the exception of the far northern areas of the state and the Jacksonville area , most of the major cities of Florida have never recorded measurable snowfall , have only recorded trace ( T ) amounts , or have only reported flurries in the air , usually just a few times each century . In the Florida Keys and Key West there is no known occurrence of snow flurries since the settlement of the region . Due to Florida 's low latitude and subtropical climate , temperatures cold enough to support significant snowfall are infrequent and their duration is fleeting . In general , frost is more common than snow , requiring temperatures of 32 ° F ( 0 ° C ) or less at 2 m above sea level , a cloudless sky , and a relative humidity of 65 % or more . Generally , for snow to occur , the polar jet stream must move southward through Texas and into the Gulf of Mexico , with a stalled cold front across the southern portion of the state curving northeastward to combine freezing air into the frontal clouds . While light snowfall occurs a few times each decade across the northern panhandle , most of the state is too far south of the cold continental air masses responsible for generating snowfall in the rest of the country . The mean maximum monthly snowfall in most parts of Florida is zero . The only other areas in the continental United States with this distinction are extreme southern Texas and parts of coastal southern California . Much of the known information on snow in Florida prior to 1900 is from climatological records provided by the National Weather Service meteorological station in Jacksonville , and information for other locations is sparse . The earliest recorded instance of snow in Florida occurred in 1774 ; being unaccustomed to snow , some Jacksonville residents called it `` extraordinary white rain . '' The first White Christmas in northeastern Florida 's history resulted from a snow event that occurred on December 23 , 1989 . |
Solar_cycle_19 | Solar cycle 19 was the nineteenth solar cycle since 1755 , when extensive recording of solar sunspot activity began . The solar cycle lasted 10.5 years , beginning in April 1954 and ending in October 1964 . The International Geophysical Year occurred at the peak of this solar cycle . The maximum smoothed sunspot number ( SIDC formula ) observed during the solar cycle was 285.0 , in March 1958 ( the highest on record ) , and the starting minimum was 5.1 . During the minimum transit from solar cycle 19 to 20 , there were a total of 227 days with no sunspots . This was the lowest number since 1850 . |
South_Pacific_tropical_cyclone | A South Pacific tropical cyclone ( Commonly referred to as hurricanes ) is a non frontal , low pressure system that has developed , within an environment of warm sea surface temperatures and little vertical wind shear aloft in the South Pacific Ocean . Within the Southern Hemisphere there are officially three areas where tropical cyclones develop on a regular basis , these areas are the South-West Indian Ocean between Africa and 90 ° E , the Australian region between 90 ° E and 160 ° E and the South Pacific basin between 160 ° E and 120 ° W . The South Pacific basin between 160 ° E and 120 ° W is officially monitored by the Fiji Meteorological Service and New Zealand 's MetService , while others like the Australian Bureau of Meteorology and the United States National Oceanic and Atmospheric Administration also monitor the basin . Each tropical cyclone year within this basin starts on July 1 and runs throughout the year , encompassing the tropical cyclone season which runs from November 1 and lasts until April 30 each season . Within the basin , most tropical cyclones have their origins within the South Pacific Convergence Zone or within the Northern Australian monsoon trough , both of which form an extensive area of cloudiness and are dominant features of the season . Within this region a tropical disturbance is classified as a tropical cyclone , when it has 10-minute sustained wind speeds of more than 65 km/h ( 35 mph ) , that wrap halfway around the low level circulation centre , while a severe tropical cyclone is classified when the maximum 10-minute sustained wind speeds are greater than 120 km/h ( 75 mph ) . |
Snakebite | A snakebite is an injury caused by the bite of a snake , especially a venomous snake . A common symptom of a bite from a venomous snake is the presence of two puncture wounds from the animal 's fangs . Sometimes venom injection from the bite may occur . This may result in redness , swelling , and severe pain at the area , which may take up to an hour to appear . Vomiting , trouble seeing , tingling of the limbs , and sweating may result . Most bites are on the hands or arms . Fear following a bite is common with symptoms of a racing heart and feeling faint . The venom may cause bleeding , kidney failure , a severe allergic reaction , tissue death around the bite , or breathing problems . Bites may result in the loss of a limb or other chronic problems . The outcome depends on the type of snake , the area of the body bitten , the amount of venom injected , and the health conditions of the person . Problems are often more severe in children than adults , due to their smaller size . Snakes bite both as a method of hunting and as a means of protection . Risk factors for bites include working outside with one 's hands such as in farming , forestry , and construction . Snakes commonly involved in poisonings include elapids ( such as kraits , cobras and mambas ) , vipers , and sea snakes . The majority of snake species do not have venom and kill their prey by squeezing them . Venomous snakes can be found on every continent except Antarctica . Determining the type of snake that caused a bite is often not possible . The World Health Organization says snakebites are a `` neglected public health issue in many tropical and subtropical countries '' . Prevention of snake bites can involve wearing protective footwear , avoiding areas where snakes live , and not handling snakes . Treatment partly depends on the type of snake . Washing the wound with soap and water and holding the limb still is recommended . Trying to suck out the venom , cutting the wound with a knife , or using a tourniquet is not recommended . Antivenom is effective at preventing death from bites ; however , antivenoms frequently have side effects . The type of antivenom needed depends on the type of snake involved . When the type of snake is unknown , antivenom is often given based on the types known to be in the area . In some areas of the world getting the right type of antivenom is difficult and this partly contributes to why they sometimes do not work . An additional issue is the cost of these medications . Antivenom has little effect on the area around the bite itself . Supporting the person 's breathing is sometimes also required . The number of venomous snakebites that occur each year may be as high as five million . They result in about 2.5 million poisonings and 20,000 to 125,000 deaths . The frequency and severity of bites vary greatly among different parts of the world . They occur most commonly in Africa , Asia , and Latin America , with rural areas more greatly affected . Deaths are relatively rare in Australia , Europe and North America . For example , in the United States , about seven to eight thousand people per year are bitten by venomous snakes ( about one in 40 thousand people ) and about five people die ( about one death per 65 million people ) . |
Slow_movement_(culture) | The slow movement ( sometimes capitalised Slow movement or Slow Movement ) advocates a cultural shift toward slowing down life 's pace . It began with Carlo Petrini 's protest against the opening of a McDonald 's restaurant in Piazza di Spagna , Rome in 1986 that sparked the creation of the slow food movement . Over time , this developed into a subculture in other areas , like the Cittaslow organisation for `` slow cities '' . The `` slow '' epithet has subsequently been applied to a variety of activities and aspects of culture . Geir Berthelsen and his creation of The World Institute of Slowness presented a vision in 1999 for an entire `` slow planet '' and a need to teach the world the way of slowness . Carl Honoré 's 2004 book , In Praise of Slowness , first explored how the Slow philosophy might be applied in every field of human endeavour and coined the phrase `` slow movement '' . The Financial Times said the book is `` to the Slow Movement what Das Kapital is to communism '' . Honoré describes the Slow Movement thus : `` It is a cultural revolution against the notion that faster is always better . The Slow philosophy is not about doing everything at a snail 's pace . It 's about seeking to do everything at the right speed . Savoring the hours and minutes rather than just counting them . Doing everything as well as possible , instead of as fast as possible . It 's about quality over quantity in everything from work to food to parenting . '' -- Reda . Professor Guttorm Fløistad summarises the philosophy , stating : `` The only thing for certain is that everything changes . The rate of change increases . If you want to hang on you better speed up . That is the message of today . It could however be useful to remind everyone that our basic needs never change . The need to be seen and appreciated ! It is the need to belong . The need for nearness and care , and for a little love ! This is given only through slowness in human relations . In order to master changes , we have to recover slowness , reflection and togetherness . There we will find real renewal . '' The slow movement is not organised and controlled by a single organisation . A fundamental characteristic of the slow movement is that it is propounded , and its momentum maintained , by individuals who constitute the expanding global community of Slow . Its popularity has grown considerably since the rise of slow food and Cittaslow in Europe , with slowness initiatives spreading as far as Australia and Japan . |
Skewness | In probability theory and statistics , skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean . The skewness value can be positive or negative , or even undefined . The qualitative interpretation of the skew is complicated and unintuitive . Skew must not be thought to refer to the direction the curve appears to be leaning ; in fact , the opposite is true ( see below ) . For a unimodal distribution , negative skew indicates that the tail on the left side of the probability density function is longer or fatter than the right side -- it does not distinguish these two kinds of shape . Conversely , positive skew indicates that the tail on the right side is longer or fatter than the left side . In cases where one tail is long but the other tail is fat , skewness does not obey a simple rule . For example , a zero value means that the tails on both sides of the mean balance out overall ; this is the case for a symmetric distribution , but is also true for an asymmetric distribution where the asymmetries even out , such as one tail being long but thin , and the other being short but fat . Further , in multimodal distributions and discrete distributions , skewness is also difficult to interpret . Importantly , the skewness does not determine the relationship of mean and median . In cases where it is necessary , data might be transformed to have a normal distribution . |
Slowdown | A slowdown ( UK : go-slow ) is an industrial action in which employees perform their duties but seek to reduce productivity or efficiency in their performance of these duties . A slowdown may be used as either a prelude or an alternative to a strike , as it is seen as less disruptive as well as less risky and costly for workers and their union . Striking workers usually go unpaid and risk being replaced , so a slowdown is seen as a way to put pressure on management while avoiding these outcomes . Other times slowdowns are accompanied by intentional sabotage on the part of workers to provide further disruption . Nonetheless , workers participating in a slowdown are often punished , sometimes by firing and other times by law . |
Souther_(meteorology) | In meteorology , Souther is a strong wind coming from the south . It 's also a term widely used in maritime jargon to indicate , in fact , generally `` strong wind from the south '' . |
Solar_cell | A solar cell , or photovoltaic cell ( previously termed `` solar battery '' ) , is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect , which is a physical and chemical phenomenon . It is a form of photoelectric cell , defined as a device whose electrical characteristics , such as current , voltage , or resistance , vary when exposed to light . Solar cells are the building blocks of photovoltaic modules , otherwise known as solar panels . Solar cells are described as being photovoltaic , irrespective of whether the source is sunlight or an artificial light . They are used as a photodetector ( for example infrared detectors ) , detecting light or other electromagnetic radiation near the visible range , or measuring light intensity . The operation of a photovoltaic ( PV ) cell requires three basic attributes : The absorption of light , generating either electron-hole pairs or excitons . The separation of charge carriers of opposite types . The separate extraction of those carriers to an external circuit . In contrast , a solar thermal collector supplies heat by absorbing sunlight , for the purpose of either direct heating or indirect electrical power generation from heat . A `` photoelectrolytic cell '' ( photoelectrochemical cell ) , on the other hand , refers either to a type of photovoltaic cell ( like that developed by Edmond Becquerel and modern dye-sensitized solar cells ) , or to a device that splits water directly into hydrogen and oxygen using only solar illumination . |
Solar_term | A solar term is any of 24 points in traditional East Asian lunisolar calendars that matches a particular astronomical event or signifies some natural phenomenon . The points are spaced 15 ° apart along the ecliptic and are used by lunisolar calendars to stay synchronized with the seasons , which is crucial for agrarian societies . The solar terms are also used to calculate intercalary months in East Asian calendars ; which month is repeated depends on the position of the sun at the time . Because the Sun 's speed along the ecliptic varies depending on the Earth-Sun distance , the number of days that it takes the Sun to travel between each pair of solar terms varies slightly throughout the year . Each solar term is divided into three pentads ( 候 hòu ) , so there are 72 pentads in a year . Each pentad consists of five , rarely six , days , and are mostly named after phenological ( biological or botanical ) phenomena corresponding to the pentad . Solar terms originated in China , then spread to Korea , Vietnam , and Japan , countries in the East Asian cultural sphere . Although each term was named based on the seasonal changes of climate in North China Plain , peoples living in the different climates still use it with no changes . This is exhibited by the fact that traditional Chinese , Hanja , and Kanji characters for most of the solar terms are identical . On December 1 , 2016 , 24 Solar Terms were listed as UNESCO 's Intangible Cultural Heritage . |
Solar_Radiation_and_Climate_Experiment | The Solar Radiation and Climate Experiment ( SORCE ) is a NASA-sponsored satellite mission that measures incoming X-ray , ultraviolet , visible , near-infrared , and total solar radiation . These measurements specifically address long-term climate change , natural variability and enhanced climate prediction , and atmospheric ozone and UV-B radiation . These measurements are critical to studies of the Sun , its effect on our Earth system and its influence on humankind . The SORCE spacecraft launched on January 25 , 2003 on a Pegasus XL launch vehicle to provide NASA 's Earth Science Enterprise ( ESE ) with precise measurements of solar radiation . SORCE measures the Sun 's output using radiometers , spectrometers , photodiodes , detectors , and bolometers mounted on a satellite observatory . The SORCE satellite orbits the Earth accumulating solar data . Spectral measurements identify the irradiance of the Sun by characterizing the Sun 's energy and emissions in the form of color that can then be translated into quantities and elements of matter . Data obtained by the SORCE experiment can be used to model the Sun 's output and to explain and predict the effect of the Sun 's radiation on the Earth 's atmosphere and climate . Flying in a 645 km , 40 degree orbit , SORCE is operated by the Laboratory for Atmospheric and Space Physics ( LASP ) at the University of Colorado at Boulder , Colorado . It will continue the precise measurements of total solar irradiance that began with the ERB instrument in 1979 and has continued to the present with the ACRIM series of measurements . SORCE will also provide the measurements of the solar spectral irradiance from 1 nm to 2000 nm , accounting for 95 % of the spectral contribution to the total solar irradiance . SORCE carries four instruments including the Total Irradiance Monitor ( TIM ) , Solar Stellar Irradiance Comparison Experiment ( SOLSTICE ) , Spectral Irradiance Monitor ( SIM ) , and the XUV Photometer System ( XPS ) . |
Solid_earth | Solid earth refers to `` the earth beneath our feet '' or terra firma , the planet 's solid surface and its interior . It contrasts with the Earth 's fluid envelopes , the atmosphere and hydrosphere ( but includes the ocean basin ) , as well as the biosphere and interactions with the sun . It includes the liquid core . Solid-earth science refers to the corresponding methods of study , a subset of Earth sciences , predominantly geophysics and geology , excluding aeronomy , atmospheric sciences , oceanography , hydrology , and ecology . |
Southern_tick-associated_rash_illness | Southern tick-associated rash illness ( STARI ) or Masters ' disease is an emerging infectious disease related to Lyme disease that occurs in southeastern and south-central United States . It is spread by tick bites , but the organism that causes the infection is unknown . |
Skeptical_Science | Skeptical Science ( occasionally abbreviated SkS ) is a climate science blog and information resource created in 2007 by Australian cognitive scientist John Cook . In addition to publishing articles on current events relating to climate science and climate policy , the site maintains a large database of articles analyzing the merit of arguments commonly put forth by those who oppose the mainstream scientific opinion on climate change . |
Solow_residual | The Solow residual is a number describing empirical productivity growth in an economy from year to year and decade to decade . Robert Solow defined rising productivity as rising output with constant capital and labor input . It is a `` residual '' because it is the part of growth that can not be explained through capital accumulation or increased labor . Note that increased physical throughput -- i.e. environmental resources -- are specifically excluded from the calculation , thus some portion of the residual can be ascribed to increased physical throughput . The Solow Residual is procyclical and is sometimes called the rate of growth of total factor productivity . |
Spanish_missions_in_California | The Spanish missions in California comprise a series of 21 religious outposts or missions established between 1769 and 1833 in today 's U.S. State of California . Founded by Catholic priests of the Franciscan order to evangelize the Native Americans , the missions led to the creation of the New Spain province of Alta California and were part of the expansion of the Spanish Empire into the most northern and western parts of Spanish North America . The major coastal cities of California were founded as a mission or sub-mission , including San Francisco , Monterey , Los Angeles and San Diego . Following long-term secular and religious policy of Spain in Latin America , the missionaries forced the native Californians to live in settlements called reductions , disrupting their traditional way of life . The missionaries introduced European fruits , vegetables , cattle , horses , ranching , and technology . This missions have been accused by critics , then and now , of various abuses and oppression . In the end , the missions had mixed results in their objectives : to convert , educate , and transform the natives into Spanish colonial citizens . In 1821 , Mexico achieved independence from Spain , taking Alta California along with it , but the missions maintained authority over native neophytes and control of land holdings until the 1830s . At the peak of its development in 1832 , the coastal mission system controlled an area equal to approximately one-sixth of Alta California . The Alta California government secularized the missions after the passage of the Mexican secularization act of 1833 . This divided the mission lands into land grants , which became many of the Ranchos of California . The surviving mission buildings are the state 's oldest structures , and its most-visited historic monuments . They have become a symbol of California , appearing in many movies and television shows , and are an inspiration for Mission Revival architecture . |
Solar_energy | Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-evolving technologies such as solar heating , photovoltaics , solar thermal energy , solar architecture , molten salt power plants and artificial photosynthesis . It is an important source of renewable energy and its technologies are broadly characterized as either passive solar or active solar depending on how they capture and distribute solar energy or convert it into solar power . Active solar techniques include the use of photovoltaic systems , concentrated solar power and solar water heating to harness the energy . Passive solar techniques include orienting a building to the Sun , selecting materials with favorable thermal mass or light-dispersing properties , and designing spaces that naturally circulate air . The large magnitude of solar energy available makes it a highly appealing source of electricity . The United Nations Development Programme in its 2000 World Energy Assessment found that the annual potential of solar energy was 1,575 -- 49,837 exajoules ( EJ ) . This is several times larger than the total world energy consumption , which was 559.8 EJ in 2012 . In 2011 , the International Energy Agency said that `` the development of affordable , inexhaustible and clean solar energy technologies will have huge longer-term benefits . It will increase countries ' energy security through reliance on an indigenous , inexhaustible and mostly import-independent resource , enhance sustainability , reduce pollution , lower the costs of mitigating global warming , and keep fossil fuel prices lower than otherwise . These advantages are global . Hence the additional costs of the incentives for early deployment should be considered learning investments ; they must be wisely spent and need to be widely shared '' . |
Solar_cell_efficiency | Solar cell efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity . The efficiency of the solar cells used in a photovoltaic system , in combination with latitude and climate , determines the annual energy output of the system . For example , a solar panel with 20 % efficiency and an area of 1 m2 will produce 200 W at Standard Test Conditions , but it can produce more when the sun is high in the sky and will produce less in cloudy conditions and when the sun is low in the sky . In central Colorado , which receives annual insolation of 5.5 kWh/m2/day , such a panel can be expected to produce 440 kWh of energy per year . However , in Michigan , which receives only 3.8 kWh/m2/day , annual energy yield will drop to 280 kWh for the same panel . At more northerly European latitudes , yields are significantly lower : 175 kWh annual energy yield in southern England . Several factors affect a cell 's conversion efficiency value , including its reflectance efficiency , thermodynamic efficiency , charge carrier separation efficiency , and conduction efficiency values . Because these parameters can be difficult to measure directly , other parameters are measured instead , including quantum efficiency , VOC ratio , and fill factor . Reflectance losses are accounted for by the quantum efficiency value , as they affect `` external quantum efficiency . '' Recombination losses are accounted for by the quantum efficiency , VOC ratio , and fill factor values . Resistive losses are predominantly accounted for by the fill factor value , but also contribute to the quantum efficiency and VOC ratio values . As of December 2014 , the world record for solar cell efficiency at 46 % was achieved by using multi-junction concentrator solar cells , developed from collaboration efforts of Soitec , CEA-Leti , France together with Fraunhofer ISE , Germany . |
South_Pole | The South Pole , also known as the Geographic South Pole or Terrestrial South Pole , is one of the two points where the Earth 's axis of rotation intersects its surface . It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole . Situated on the continent of Antarctica , it is the site of the United States Amundsen -- Scott South Pole Station , which was established in 1956 and has been permanently staffed since that year . The Geographic South Pole should not be confused with the South Magnetic Pole , which is defined based on the Earth 's magnetic field . The South Pole is at the center of the Southern Hemisphere . |
Solar_power_in_Spain | Spain is one of the most advanced countries in the development of solar energy , and it is one of the European countries with the most hours of sunshine . Through a ministerial ruling in March 2004 , the Spanish government removed economic barriers to the connection of renewable energy technologies to the electricity grid . The Royal Decree 436/2004 equalized conditions for large-scale solar thermal and photovoltaic plants and guaranteed feed-in tariffs . In the wake of the 2008 financial crisis , the Spanish government drastically cut its subsidies for solar power and capped future increases in capacity at 500 MW per year , with effects upon the industry worldwide . In 2008 the Spanish government committed to achieving a target of 12 % of primary energy from renewable energy by 2010 and by 2020 expects the installed solar generating capacity of 10 GW . Spain is the fourth largest manufacturer in the world of solar power technology and exports 80 % of this output to Germany . Spain added a record 2.6 GW of solar photovoltaic power in 2008 , increasing capacity to 3.5 GW . In 2016 , nearly 8 TWh was produced from photovoltaics , and 5 TWh from solar thermal . By the end of 2012 , 4.5 GW had been installed , and that year 8.2 TWh of electricity was produced . Since then , new installations of solar photovoltaics have slowed down significantly . Since 2010 , Spain has been the world 's leader in concentrated solar power ( CSP ) , and by the end of 2012 had installed over 2,000 MW of CSP . |
Soot | Soot -LSB- ˈsʊt -RSB- is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons . It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed fuel particles such as coal , cenospheres , charred wood , and petroleum coke that may become airborne during pyrolysis and that are more properly identified as cokes or chars . Soot causes cancer and lung disease , and is the second-biggest human cause of global warming . |
Solar_bonds | Solar bonds are municipal revenue bonds issued to provide low-interest financing for lower-cost accelerated development of local renewable energy technologies such as solar photovoltaics . The first solar bond authority was drafted by Paul Douglas Fenn , creator of Community Choice Aggregation , and approved by San Francisco , California voters in 2001 . Under `` solar neighborhoods '' approach , municipal governments would enter into multi-decade community-wide power purchase agreements with competitive suppliers and issue solar bonds , or `` H Bonds '' , to finance the new supplier 's rollout of local renewable energy and energy efficiency measures , offering municipal bond financing to residents and businesses , the debt for which would be repaid on monthly electric bills - an approach that has come to be called `` on-bill financing . '' The City of San Francisco enshrined solar bonds in its Community Choice Aggregation program in 2004 when it adopted an ordinance combining the City 's authority to procure power for its residents and businesses with its authority to issue revenue bonds under the solar bond authority . Fenn drafted the ordinance ( 86-04 , 2004 ) for sponsoring supervisor Tom Ammiano , who had also sponsored placing the solar bond authority on the 2001 ballot , and Fenns ' company , Local Power Inc. , went on to draft a 2007 implementation plan and 2013 business model to implement the $ 1 billion project . Local Power also contributed substantially to Sonoma county 's Sonoma Clean Power program which has a similar structure . Apart from creating a new generation of Community Choice Aggregations , San Francisco 's solar bond authority spawned the subsequent appearance of both public and private financing of customer-owned solar and energy efficiency measures , including PACE financing and the solar power purchase agreement or PPA , transforming the photovoltaics industry in the United States . |
Solar_eclipse | As seen from the Earth , a solar eclipse is a type of eclipse that occurs when the Moon passes between the Sun and Earth , and the Moon fully or partially blocks ( `` occults '' ) the Sun . This can happen only at new moon when the Sun and the Moon are in conjunction as seen from Earth in an alignment referred to as syzygy . In a total eclipse , the disk of the Sun is fully obscured by the Moon . In partial and annular eclipses , only part of the Sun is obscured . If the Moon were in a perfectly circular orbit , a little closer to the Earth , and in the same orbital plane , there would be total solar eclipses every month . However , the Moon 's orbit is inclined ( tilted ) at more than 5 degrees to the Earth 's orbit around the Sun ( see ecliptic ) , so its shadow at new moon usually misses Earth . Earth 's orbit is called the ecliptic plane as the Moon 's orbit must cross this plane in order for an eclipse ( both solar as well as lunar ) to occur . In addition , the Moon 's actual orbit is elliptical , often taking it far enough away from Earth that its apparent size is not large enough to block the Sun totally . The orbital planes cross each other at a line of nodes resulting in at least two , and up to five , solar eclipses occurring each year ; no more than two of which can be total eclipses . However , total solar eclipses are rare at any particular location because totality exists only along a narrow path on the Earth 's surface traced by the Moon 's shadow or umbra . An eclipse is a natural phenomenon . Nevertheless , in some ancient and modern cultures , solar eclipses have been attributed to supernatural causes or regarded as bad omens . A total solar eclipse can be frightening to people who are unaware of its astronomical explanation , as the Sun seems to disappear during the day and the sky darkens in a matter of minutes . Since looking directly at the Sun can lead to permanent eye damage or blindness , special eye protection or indirect viewing techniques are used when viewing a solar eclipse . It is technically safe to view only the total phase of a total solar eclipse with the unaided eye and without protection ; however , this is a dangerous practice , as most people are not trained to recognize the phases of an eclipse , which can span over two hours while the total phase can only last a maximum of 7.5 minutes for any one location . People referred to as eclipse chasers or umbraphiles will travel to remote locations to observe or witness predicted central solar eclipses . For the date of the next eclipse see the section Recent and forthcoming solar eclipses . |
Solar_power_in_Australia | Solar power in Australia is a growing industry . As of April 2017 , Australia had over 5,920 megawatts ( MW ) of installed photovoltaic ( PV ) solar power , of which 771 MW were installed in the preceding 12 months . In addition , 22 solar PV projects with a combined installed capacity of 1,922 MW are either under construction , constructed or will start construction in 2017 having reached financial closure . PV contributed to 2.4 % of the country 's electrical energy for 2014-2015 . The installed PV capacity in Australia has increased 10-fold between 2009 and 2011 , and quadrupled between 2011 and 2016 . Feed-in tariffs and mandatory renewable energy targets designed to assist renewable energy commercialisation in Australia have largely been responsible for the rapid increase . In South Australia , a solar feed-in tariff was introduced for households and an educational program that involved installing PVs on the roofs of major public buildings such as the Adelaide Airport , State Parliament , Museum , Art Gallery and several hundred public schools . In 2008 Premier Mike Rann announced funding for $ 8 million worth of solar panels on the roof of the new Goyder Pavilion at the Royal Adelaide Showgrounds , the largest rooftop solar installation in Australia , qualifying it for official `` power station '' status . South Australia has the highest per capita take up of household solar power in Australia . The first commercial-scale PV power plant , the 1 MW Uterne Solar Power Station , was opened in 2011 . The second opened in 2012 at Greenough River Solar Farm with a capacity of 10 MW . The price of photovoltaics has been decreasing , and in January 2013 , was less than half the cost of using grid electricity in Australia . Australia has been internationally criticised for producing very little of its energy from solar power , despite its vast resources , extensive sunshine and overall high potential . |
Snow | Snow pertains to frozen crystalline water throughout its life cycle , starting when it precipitates from clouds and accumulates on surfaces , then metamorphoses in place , and ultimately melts , slides or sublimates away . Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air . Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets , which freeze in hexagonal-shaped crystals . Snowflakes take on a variety of shapes , basic among these are platelets , needles , columns and rime . As snow accumulates into a snowpack , it may blow into drifts . Over time , accumulated snow metamorphoses , by sintering , sublimation and freeze-thaw . Where the climate is cold enough for year-to-year accumulation , a glacier may form . Otherwise , snow typically melts seasonally , causing runoff into streams and rivers and recharging groundwater . Major snow-prone areas include the polar regions , the upper half of the Northern Hemisphere and mountainous regions worldwide with sufficient moisture and cold temperatures . In the Southern Hemisphere , snow is confined primarily to mountainous areas , apart from Antarctica . Snow affects such human activities as transportation : creating the need for keeping roadways , wings , and windows clear ; agriculture : providing water to crops and safeguarding livestock ; such sports as skiing , snowboarding , snowmachine travel ; and warfare : impairing target acquisition , degrading the performance of combatants and materiel , and impeding mobility . Snow affects ecosystems , as well , by providing an insulating layer during winter under which plants and animals are able to survive the cold . |
Southern_France | Southern France or the South of France , colloquially known as le Midi , is a defined geographical area consisting of the regions of France that border the Atlantic Ocean south of the Marais Poitevin , Spain , the Mediterranean , and Italy . The Midi includes : Aquitaine The island of Corsica Languedoc-Roussillon Midi-Pyrénées Poitou-Charentes ( the southern parts ) Provence-Alpes-Côte d'Azur Rhône-Alpes ( the southern parts ) This area corresponds in large part to Occitania , the territory in which Occitan ( langue d'oc ) -- as distinct from the langues d'oïl of northern France -- was historically the dominant language . Though part of Occitania , the regions of Auvergne and Limousin are not normally considered part of the South of France . The term Midi derives from mi ( middle ) and di ( day ) in Old French , comparable to the term Mezzogiorno from the south of Italy . The time of midday was synonymous with the direction of south because in France , as in all of the Northern Hemisphere north of the Tropic of Cancer , the sun is in the south at noon . The synonymy existed in Middle French as well , where meridien can refer to both midday and south . The Midi is considered to start at Valence , hence the saying '' à Valence le Midi commence '' . |
Solar_panel | Solar panels absorb the sunlight as a source of energy to generate electricity or heat . A photovoltaic ( PV ) module is a packaged , connect assembly of typically 6x10 photovoltaic solar cells . Photovoltaic modules constitute the photovoltaic array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications . Each module is rated by its DC output power under standard test conditions ( STC ) , and typically ranges from 100 to 365 Watts ( W ) . The efficiency of a module determines the area of a module given the same rated output an 8 % efficient 230 W module will have twice the area of a 16 % efficient 230 W module . There are a few commercially available solar modules that exceed efficiency of 22 % and reportedly also exceeding 24 % . A single solar module can produce only a limited amount of power ; most installations contain multiple modules . A photovoltaic system typically includes an array of photovoltaic modules , an inverter , a battery pack for storage , interconnection wiring , and optionally a solar tracking mechanism . The most common application of solar panels is solar water heating systems . The price of solar power has continued to fall so that in many countries it is cheaper than ordinary fossil fuel electricity from the grid ( there is `` grid parity '' ) . |
Southern_California | Southern California , often abbreviated as SoCal , is a geographic and cultural region that generally comprises California 's 10 southernmost counties . The region is traditionally described as eight counties , based on demographics and economic ties : Imperial , Los Angeles , Orange , Riverside , San Bernardino , San Diego , Santa Barbara , and Ventura . The more extensive 10-county definition , which includes Kern and San Luis Obispo counties , is also used and is based on historical political divisions . The 8-county and 10-county definitions are not used for the greater Southern California Megaregion , one of the 11 megaregions of the United States . The megaregion is more expansive , extending east into Las Vegas , Nevada and south across the Mexican border into Tijuana . Southern California includes the heavily built-up urban area which stretches along the Pacific coast from Ventura through the Greater Los Angeles Area and the Inland Empire , and down to Greater San Diego . Southern California 's population encompasses seven metropolitan areas : the Los Angeles metropolitan area ( Los Angeles and Orange counties ) , the Inland Empire , ( Riverside and San Bernardino counties ) , the San Diego metropolitan area , the Oxnard -- Thousand Oaks -- Ventura metropolitan area , the Santa Barbara metropolitan area , the San Luis Obispo metropolitan area , and the El Centro area . The Los Angeles area has over 12 million inhabitants , while the Riverside-San Bernardino area has over 4 million inhabitants and the San Diego area has over 3 million inhabitants . For Community Supported Agriculture ( CSA ) metropolitan purposes , the five counties of Los Angeles , Orange , Riverside , San Bernardino , and Ventura , are all combined to make up the Greater Los Angeles Area with over 17.5 million people . With over 22 million people , Southern California contains roughly 60 percent of California 's population . The Colorado Desert and the Colorado River are located on Southern California 's eastern border with Arizona , and the Mojave Desert is located north on California 's Nevada border . Southern California 's southern border is part of the Mexico -- United States border . |
Social_research | Social research is research conducted by social scientists following a systematic plan . Social research methodologies can be classified along a quantitative/qualitative dimension . Quantitative designs approach social phenomena through quantifiable evidence , and often rely on statistical analysis of many cases ( or across intentionally designed treatments in an experiment ) to create valid and reliable general claims . Related to quantity . Qualitative designs emphasize understanding of social phenomena through direct observation , communication with participants , or analysis of texts , and may stress contextual subjective accuracy over generality . Related to quality . While methods may be classified as quantitative or qualitative , most methods contain elements of both . For example , qualitative data analysis often involves a fairly structured approach to coding the raw data into systematic information , and quantifying intercoder reliability . Thus , there is often a more complex relationship between `` qualitative '' and `` quantitative '' approaches than would be suggested by drawing a simple distinction between them . Social scientists employ a range of methods in order to analyse a vast breadth of social phenomena : from census survey data derived from millions of individuals , to the in-depth analysis of a single agent 's social experiences ; from monitoring what is happening on contemporary streets , to the investigation of ancient historical documents . Methods rooted in classical sociology and statistics have formed the basis for research in other disciplines , such as political science , media studies , program evaluation and market research . |
Southern_Tenant_Farmers_Union | The Southern Tenant Farmers ' Union ( STFU ) was founded in 1934 as a civil farmer 's union to organize tenant farmers in the Southern United States . Originally set up during the Great Depression , the STFU was founded to help sharecroppers and tenant farmers get better arrangements from landowners . They were eager to improve their share of profit or subsidies and working conditions . The STFU was established as a response to policies of the Agricultural Adjustment Administration ( AAA ) . Part of the New Deal , the AAA was a program to reduce production in order to increase prices of commodities ; landowners were paid subsidies , which they were supposed to pass on to their tenants . was designed by President Franklin D. Roosevelt to help revive the United States ' agricultural industry and to recharge the depressed economy . The AAA called for a reduction in food production , which would , through a controlled shortage of food , raise the price for any given food item through supply and demand . The desired effect was that the agricultural industry would prosper due to the increased value and produce more income for farmers . In order to decrease food production , the AAA paid farmers to hold some of their land out of production ; the money was paid to the landowners . The landowners were expected to share this money with the tenant farmers . While a small percentage of the landowners did share the income , the majority did not . The Southern Tenant Farmers ' Union was one of few unions in the 1930s that was open to all races . They promoted non-violent protest to gain their fair share of the AAA money . They also promoted the goal of blacks and whites working efficiently together . The Farmers ' Union met with harsh resistance from the landowners and local public officials . The Southern Tenant Farmers ' Union leaders were often harassed , attacked and many were killed . In the 1930s the union was active in Arkansas , Oklahoma , Mississippi , Missouri , Tennessee and Texas . It later spread into the southeastern states and to California , sometimes affiliating with larger national labor federations . Its headquarters was mainly at Memphis , Tennessee . From 1948 to 1960 , it was based at Washington , D.C. . It was later known as the National Agricultural Workers Union and the Agricultural and Allied Workers Union . |
Soil | Soil is a mixture of minerals , organic matter , gases , liquids , and countless organisms that together support life on Earth . Soil is a natural body called the pedosphere which has four important functions : it is a medium for plant growth ; it is a means of water storage , supply and purification ; it is a modifier of Earth 's atmosphere ; it is a habitat for organisms ; all of which , in turn , modify the soil . Soil is called the Skin of the Earth and interfaces with the lithosphere , the hydrosphere , the atmosphere , and the biosphere . The term pedolith , used commonly to refer to the soil , literally translates ground stone . Soil consists of a solid phase of minerals ( the soil matrix ) and organic matter , as well as a porous phase that holds gases ( the soil atmosphere ) and water ( the soil solution ) . Accordingly , soils are often treated as a three-state system of solids , liquids , and gases . Soil is a product of the influence of climate , relief ( elevation , orientation , and slope of terrain ) , organisms , and its parent materials ( original minerals ) interacting over time . Soil continually undergoes development by way of numerous physical , chemical and biological processes , which include weathering with associated erosion . Given its complexity and strong internal connectedness soil has been considered as an ecosystem by soil ecologists . Most soils have a dry bulk density ( density of soil taking into account voids when dry ) between 1.1 and 1.6 g/cm3 , while the soil particle density is much higher , in the range of 2.6 to 2.7 g/cm3 . Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic , although fossilized soils are preserved from as far back as the Archean . Soil science has two basic branches of study : edaphology and pedology . Edaphology is concerned with the influence of soils on living things . Pedology is focused on the formation , description ( morphology ) , and classification of soils in their natural environment . In engineering terms , soil is referred to as regolith , or loose rock material that lies above the solid geology . Soil is commonly referred to as earth or dirt ; technically , the term dirt should be restricted to displaced soil . As soil resources serve as a basis for food security , the international community advocates its sustainable and responsible use through different types of soil governance . |
Spherical_Earth | The earliest reliably documented mention of the spherical Earth concept dates from around the 6th century BC when it appeared in ancient Greek philosophy but remained a matter of speculation until the 3rd century BC , when Hellenistic astronomy established the spherical shape of the Earth as a physical given . The paradigm was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages . A practical demonstration of Earth 's sphericity was achieved by Ferdinand Magellan and Juan Sebastián Elcano 's expedition 's circumnavigation ( 1519 − 1522 ) . The concept of a spherical Earth displaced earlier beliefs in a flat Earth : In early Mesopotamian mythology , the world was portrayed as a flat disk floating in the ocean and surrounded by a spherical sky , and this forms the premise for early world maps like those of Anaximander and Hecataeus of Miletus . Other speculations on the shape of Earth include a seven-layered ziggurat or cosmic mountain , alluded to in the Avesta and ancient Persian writings ( see seven climes ) . The realization that the figure of the Earth is more accurately described as an ellipsoid dates to the 17th century , as described by Isaac Newton in Principia . In the early 19th century , the flattening of the earth ellipsoid was determined to be of the order of 1/300 ( Delambre , Everest ) . The modern value as determined by the US DoD World Geodetic System since the 1960s is close to 1/298 .25 . |
Southern_Hemisphere | The Southern Hemisphere is the half sphere of Earth which is south of the equator . It contains all or parts of five continents ( Antarctica , Australia , about 90 % of South America , the southern third of Africa , and several southern islands off the continental mainland of Asia ) , four oceans ( Indian , South Atlantic , Southern , and South Pacific ) and most of the Pacific Islands in Oceania . Its surface is 80.9 % water , compared with 60.7 % water in the case of the Northern Hemisphere , and it contains 32.7 % of Earth 's land . Due to the tilt of Earth 's rotation relative to the Sun and the ecliptic plane , summer is from December to March and winter is from June to September . September 22 or 23 is the vernal equinox and March 20 or 21 is the autumnal equinox . The South Pole is in the middle of the southern hemispherical region . |
Solar_prominence | A prominence is a large , bright , gaseous feature extending outward from the Sun 's surface , often in a loop shape . Prominences are anchored to the Sun 's surface in the photosphere , and extend outwards into the Sun 's corona . While the corona consists of extremely hot ionized gases , known as plasma , which do not emit much visible light , prominences contain much cooler plasma , similar in composition to that of the chromosphere . The prominence plasma is typically a hundred times more lit and denser than the coronal plasma . A prominence forms over timescales of about a day and may persist in the corona for several weeks or months , looping hundreds of thousands of miles into space . Some prominences break apart and may then give rise to coronal mass ejections . Scientists are currently researching how and why prominences are formed . The red-glowing looped material is plasma , a hot gas composed of electrically charged hydrogen and helium . The prominence plasma flows along a tangled and twisted structure of magnetic fields generated by the sun 's internal dynamo . An erupting prominence occurs when such a structure becomes unstable and bursts outward , releasing the plasma . A typical prominence extends over many thousands of kilometers ; the largest on record was estimated at over 800,000 km long -- roughly the radius of the Sun . |
Solar_storm_of_1859 | The Solar storm of 1859 -- known as the Carrington Event -- was a powerful geomagnetic solar storm during solar cycle 10 ( 1855 -- 1867 ) . A solar coronal mass ejection hit Earth 's magnetosphere and induced one of the largest geomagnetic storms on record , September 1 -- 2 , 1859 . The associated `` white light flare '' in the solar photosphere was observed and recorded by English astronomers Richard C. Carrington ( 1826 -- 1875 ) and Richard Hodgson ( 1804 -- 1872 ) . Studies have shown that a solar storm of this magnitude occurring today would likely cause more widespread problems for a modern and technology-dependent society . The solar storm of 2012 was of similar magnitude , but it passed Earth 's orbit without striking the planet . |
Spitzer_Space_Telescope | The Spitzer Space Telescope ( SST ) , formerly the Space Infrared Telescope Facility ( SIRTF ) , is an infrared space telescope launched in 2003 . It is the fourth and final of the NASA Great Observatories program . The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted . This occurred on 15 May 2009 . Without liquid helium to cool the telescope to the very low temperatures needed to operate , most of the instruments are no longer usable . However , the two shortest-wavelength modules of the IRAC camera are still operable with the same sensitivity as before the cryogen was exhausted , and will continue to be used in the Spitzer Warm Mission . All Spitzer data , from both the primary and warm phases , are archived at the Infrared Science Archive ( IRSA ) . In keeping with NASA tradition , the telescope was renamed after its successful demonstration of operation , on 18 December 2003 . Unlike most telescopes that are named after famous deceased astronomers by a board of scientists , the new name for SIRTF was obtained from a contest open to the general public . The contest led to the telescope being named in honor of astronomer Lyman Spitzer , who had promoted the concept of space telescopes in the 1940s . Spitzer wrote a 1946 report for RAND Corporation describing the advantages of an extraterrestrial observatory and how it could be realized with available or upcoming technology . He has been cited for his pioneering contributions to rocketry and astronomy , as well as `` his vision and leadership in articulating the advantages and benefits to be realized from the Space Telescope Program . '' The Spitzer was launched on 25 August 2003 at 05:35:39 UTC from Cape Canaveral SLC-17B aboard a Delta II 7920H rocket . It follows a heliocentric instead of geocentric orbit , trailing and drifting away from Earth 's orbit at approximately 0.1 astronomical unit per year ( a so-called `` earth-trailing '' orbit ) . The primary mirror is 85 cm in diameter , , made of beryllium and was cooled to 5.5 K . The satellite contains three instruments that allow it to perform astronomical imaging and photometry from 3.6 to 160 micrometers , spectroscopy from 5.2 to 38 micrometers , and spectrophotometry from 5 to 100 micrometers . |
Square_mile | The square mile ( abbreviated as sq mi and sometimes as mi ² ) is an imperial and US unit of measure for an area equal to the area of a square of one statute mile . It should not be confused with miles square , which refers to a square region with each side having the specified length . For instance , 20 miles square ( 20 × 20 miles ) has an area equal to 400 square miles ; a rectangle of 10 × 40 miles likewise has an area of 400 square miles , but it is not 20 miles square . One square mile is equal to : 4,014,489,600 square inches 27,878,400 square feet 3,097,600 square yards 640 acres 2560 roods A square mile is equivalent to the following metric measures : 25,899,881,103.36 square centimetres 2,589,988.110336 square metres 258.9988110336 hectares 2.589988110336 square kilometres When applied to a portion of the earth 's surface , which is curved rather than flat , `` square mile '' is an informal synonym for section . Romans derived measurements from marching . Five feet was equal to one pace ( which is appropriately a double step ) . 1,000 paces measured a Roman mile , which was somewhat smaller than the English statute mile . This Roman system was adopted , with local variations , throughout Europe as the Roman Empire spread . Total population in a square mile is derived by dividing the total number of residents by the number of square miles of land area in the specified geographic area . The population per square kilometer is derived by multiplying the population per square mile by 0.3861 . Land area measurements are originally recorded as whole square meters . Square meters are converted to square kilometers by dividing by 1,000,000 ; square kilometers are converted to square miles by dividing by 2.58999 ; square meters are converted to square miles by dividing by 2,589,988 . |
Space_law | Space law encompasses national and international law governing activities in outer space . International lawyers have been unable to agree on a uniform definition of the term `` outer space '' , although most lawyers agree that outer space generally begins at the lowest altitude above sea level at which objects can orbit the Earth , approximately 100 km ( the Kármán line ) . The inception of the field of space law began with the launch of the world 's first artificial satellite by the Soviet Union in October 1957 . Named Sputnik 1 , the satellite was launched as part of the International Geophysical Year . Since that time , space law has evolved and assumed more importance as mankind has increasingly come to use and rely on space-based resources . |
Six_Californias | Six Californias was a proposed initiative to split the U.S. state of California into six states . It failed to qualify as a California ballot measure for the 2016 state elections due to receiving insufficient signatures . Venture capitalist Tim Draper launched the measure in December 2013 . He spent in excess of $ 5 million to try to qualify the proposition for the ballot , with nearly $ 450,000 just for political consultants . Had the measure passed , it would not have legally split California immediately ; consent would eventually need to be given by both the California State Legislature and the U.S. Congress to admit the new states to the union per Article IV , Section 3 of the U.S. Constitution . Rather , the measure would have established several procedures within the state government and its 58 counties to prepare California for the proposed split , and instructed the Governor of California to submit the state-splitting proposal to Congress . The proposed states would have been named Jefferson , North California , Silicon Valley , Central California , West California , and South California . Draper 's stated reasoning for the proposal was that the state is too large and ungovernable , and he therefore wanted to split California to produce six smaller and more efficient state governments . Opponents argued that it would have been a waste of money and resources to split California and create these new governments . Critics also charged that this was a money and political power grab designed to separate California 's wealthy areas from the poor , and to diminish the state 's reliability as a predominantly Democratic Party-supporting `` blue state '' . |
Social_fact | In sociology , social facts are the values , cultural norms , and social structures which transcend the individual and are capable of exercising social control . French sociologist Émile Durkheim defined the term and argued that the discipline of Sociology should be understood as the empirical study of social facts . For Durkheim , social facts `` consist of manners of acting , thinking and feeling external to the individual , which are invested with a coercive power by virtue of which they exercise control over him '' . |
Solar_power_in_Italy | Solar power in Italy has increased rapidly in recent years with the country ranking among the world 's largest producers of electricity from solar power . Solar power accounted for 7 % of the electricity generated in Italy during 2013 ( ranked 1st in the world ) , a share that 's expected to double by 2030 . As of April 2016 Italy had the worlds fifth largest installed solar PV capacity ( behind 1 . China 2 . Germany . 3 . Japan 4 . USA and ahead of the 6 . UK . ) The years 2009-2013 saw a boom in installed photovoltaic nameplate capacity , increasing nearly 15-fold , and 2013 's year-end capacity of 17,928 MW ranked third in the world , ahead of the United States at that time . This was partly due to the generous solar PV power generation incentives offered under the Conto Energia schemes ( see below ) . As of December 2013 , the installed capacity is approaching 18 GW , with a production so important that several gas turbine power plants currently operate at half their potential during the day . The sector provides employment to about 100,000 people , especially in design and installation . The Montalto di Castro Photovoltaic Power Station is the largest photovoltaic power station in Italy , in Montalto di Castro in Viterbo province . The project was built in several phases . The first phase with a total capacity of 24 MW was connected in late 2009 . The second phase ( 8 MW ) was commissioned in 2010 , and the third and fourth phases , totaling 44 MW , were completed in December 2010 , bringing the total to 85 MW . |
Social_and_economic_stratification_in_Appalachia | The Appalachian region of the Eastern United States is home to over 25 million people and covers parts of mostly mountainous areas of 13 states , including Mississippi , Alabama , Pennsylvania , New York , Georgia , South Carolina , North Carolina , Tennessee , Virginia , Kentucky , Ohio , Maryland , and the entire state of West Virginia . The near-isolation of the area 's rugged topography is home to communities with a distinct culture , who in many cases are put at a disadvantage because of the transportation and infrastructure problems that have developed . Appalachia is often divided into three regions -- southern ( portions of Georgia , Alabama , Mississippi , North and South Carolina , and Tennessee ) , central ( portions of Kentucky , West Virginia , Ohio , Virginia , and Tennessee ) , and northern ( parts of New York , Pennsylvania , Maryland , and Ohio ) Appalachia . Though all areas of Appalachia share problems of rural poverty , inadequate jobs , services , transportation , education , and infrastructure , some elements ( particularly those relating to industry and natural resource extraction ) are unique to each sub-region . For example , Appalachians in the central sub-region experience the deepest poverty , partially due to the area 's isolation from urban growth centers . Appalachia is particularly interesting in the context of social and economic divisions within and between the region 's socioeconomic communities . In addition , outsiders ' often incorrect and over-generalized external perspectives , and their relationship to culture and folklore of this near-isolated area , are important to the region 's future development . |
Sloth_bear | The sloth bear ( Melursus ursinus ) , also known as the labiated bear , is an insectivorous bear species native to the Indian subcontinent . The sloth bear evolved from ancestral brown bears during the Pleistocene and shares features found in insect-eating mammals through convergent evolution . The population isolated in Sri Lanka is considered a subspecies . Compared to brown and black bears , sloth bears have lankier builds , long , shaggy coats that form a mane around the face , long , sickle-shaped claws , and a specially adapted lower lip and palate used for sucking insects . Sloth bears breed during spring and early summer and give birth near the beginning of winter . They feed on termites , honeybee colonies , and fruits . Sloth bears sometimes attack humans who encroach on their territories . Historically , humans have drastically reduced their habitat and diminished their population by hunting them for food and products such as their bacula and claws . These bears have been used as performing pets due to their tameable nature . The sloth bear is listed as Vulnerable by the IUCN due to habitat loss and poaching . |
Snowpack | Snowpack forms from layers of snow that accumulate in geographic regions and high altitudes where the climate includes cold weather for extended periods during the year . Snowpacks are an important water resource that feed streams and rivers as they melt . Therefore , snowpacks are both the drinking water source for many communities and a potential source of flooding ( in case of sudden melting ) . Snowpacks also contribute mass to glaciers in their accumulation zone . Assessing the formation and stability of snowpacks is important in the study and prediction of avalanches . Scientists study the physical properties of snow under different conditions and their evolution , and more specifically snow metamorphism , snow hydrology ( that is , the contribution of snow melt to catchment hydrology ) , the evolution of snow cover with climate change and its effect on the ice-albedo feedback and hydrology . Snow is also studied in a more global context of impact on animal habitats and plant succession . An important effort is put into snow classification , both as an hydrometeor and on the ground . |
South_Atlantic_Convergence_Zone | The South Atlantic convergence zone , or SACZ , is an elongated axis of clouds , precipitation , and convergent winds oriented in a northwest-southeast manner across southeast Brazil into the southwest Atlantic Ocean . By definition , the feature is a monsoon trough . It is strongest in the warm season . Thunderstorm activity along the feature magnifies over three or more days when the Madden -- Julian oscillation passes into the region , due to the enhanced upper divergence . Low level winds over Rondônia are tied to the strength of this zone , where westerly wind anomalies correlate to active phases of the South American monsoon , while easterly wind anomalies indicate breaks of activity along the SACZ . The feature is also strongest with negative anomalies in the sea surface temperature pattern lie over the southern Atlantic Ocean , while opposite conditions prevail across the northern Atlantic Ocean . |
Spitsbergen | Spitsbergen ( formerly known as West Spitsbergen ; Norwegian : Vest Spitsbergen or Vestspitsbergen ) is the largest and only permanently populated island of the Svalbard archipelago in northern Norway . Constituting the westernmost bulk of the archipelago , it borders the Arctic Ocean , the Norwegian Sea , and the Greenland Sea . Spitsbergen covers an area of 37673 km2 , making it the largest island in Norway and the 36th-largest in the world . The administrative centre is Longyearbyen . Other settlements , in addition to research outposts , are the Russian mining community of Barentsburg , the research community of Ny-Ålesund , and the mining outpost of Sveagruva . Area covered with ice in ( 1999 ) , 21 977 sq.km. , approximately 58,5 % of total area . The island was first used as a whaling base in the 17th and 18th centuries , after which it was abandoned . Coal mining started at the end of the 19th century and several permanent communities were established . The Svalbard Treaty of 1920 recognized Norwegian sovereignty and established Svalbard as a free economic zone and a demilitarized zone . The Norwegian Store Norske and the Russian Arktikugol remain the only mining companies . Research and tourism have become important supplementary industries , featuring among others the University Centre in Svalbard and the Svalbard Global Seed Vault . No roads connect the settlements ; instead snowmobiles , aircraft , and boats serve as local transport . Svalbard Airport , Longyear provides the main point of entry and exit . The island has an Arctic climate , although with significantly higher temperatures than other places at the same latitude . The flora benefits from the long period of midnight sun , which compensates for the polar night . Svalbard is a breeding ground for many seabirds , and also supports polar bears , reindeer and marine mammals . Six national parks protect the largely untouched , yet fragile environment . The island has many glaciers , mountains and fjords . |
Solar_phenomena | Solar phenomena are the natural phenomena occurring within the magnetically heated outer atmospheres in the Sun . These phenomena take many forms , including solar wind , radio wave flux , energy bursts such as solar flares , coronal mass ejection or solar eruptions , coronal heating and sunspots . These phenomena are generated by a helical dynamo near the center of the Sun 's mass that generates strong magnetic fields and a chaotic dynamo near the surface that generates smaller magnetic field fluctuations . The total sum of all solar fluctuations is referred to as solar variation . The collective effect of all solar variations within the Sun 's gravitational field is referred to as space weather . A major weather component is the solar wind , a stream of plasma released from the Sun 's upper atmosphere . It is responsible for the aurora , natural light displays in the sky in the Arctic and Antarctic . Space weather disturbances can cause solar storms on Earth , disrupting communications , as well as geomagnetic storms in Earth 's magnetosphere and sudden ionospheric disturbances in the ionosphere . Variations in solar intensity also affect Earth 's climate . These variations can explain events such as ice ages and the Great Oxygenation Event , while the Sun 's future expansion into a red giant will likely end life on Earth . Solar activity and related events have been recorded since the 8th century BCE . Babylonians inscribed and possibly predicted solar eclipses , while the earliest extant report of sunspots dates back to the Chinese Book of Changes , . The first extant description of the solar corona was in 968 , while the earliest sunspot drawing was in 1128 and a solar prominence was described in 1185 in the Russian Chronicle of Novgorod . The invention of the telescope allowed major advances in understanding , allowing the first detailed observations in the 1600s . Solar spectroscopy began in the 1800s , from which properties of the solar atmosphere could be determined , while the creation of daguerreotypy led to the first solar photographs on 2 April 1845 . Photography assisted in the study of solar prominences , granulation and spectroscopy . Early in the 20th century , interest in astrophysics surged in America . A number of new observatories were built with solar telescopes around the world . The 1931 invention of the coronagraph allowed the corona to be studied in full daylight . |
Southwestern_United_States | The Southwestern United States ( also known as the American Southwest ) is a region of the United States which includes Arizona , the western portion of New Mexico , bordered on the east by the Llano Estacado , southern Colorado and Utah below the 39th parallel , the `` horn '' of Texas below New Mexico , the southernmost triangle of Nevada , and the most southeastern portion of California , which encompasses the Mojave and Colorado Deserts . The population of the area is around 11 million people , with over half that in Arizona ; the most populous cities are Phoenix , El Paso , Las Vegas , Albuquerque , and Tucson . Most of the area was part of the Viceroyalty of New Spain in the Spanish Empire before becoming part of Mexico . It became part of the United States through the Treaty of Guadalupe Hidalgo and the Gadsden Purchase . |
Southern_United_States | The Southern United States , commonly referred to as the American South , Dixie , or simply the South , is a region of the United States of America . The South does not fully match the geographic south of the United States , but the Deep South is fully located in the southeastern corner . Arizona and New Mexico , which are geographically in the southern part of the country , are rarely considered part , while West Virginia , which separated from Virginia in 1863 , commonly is . Some scholars have proposed definitions of the South that do not coincide neatly with state boundaries . While the states of Delaware and Maryland , as well as the District of Columbia permitted slavery prior to the start of the Civil War , they remained with the Union . Since the Civil Rights Movement of the 1960s , they became more culturally , economically , and politically aligned with the industrial Northern states , and are often identified as part of the Mid-Atlantic or Northeast by many residents , businesses , public institutions , and private organizations . However , the United States Census Bureau puts them in the South . Usually , the South is defined as including the southeastern and south-central United States . The region is known for its culture and history , having developed its own customs , musical styles , and cuisines , which have distinguished it in some ways from the rest of the United States . The Southern ethnic heritage is diverse and includes strong European ( mostly Spanish American Irish/Scotch-Irish , Scottish , English , German and French ) , African , and some Native American components . Some other aspects of the historical and cultural development of the South have been influenced by the institution of slave labor on plantations in the Deep South to an extent seen nowhere else in the United States ; the presence of a large proportion of African Americans in the population ; support for the doctrine of states ' rights , and the legacy of racial tension magnified by the Civil War and Reconstruction Era , as seen in thousands of lynchings ( mostly from 1880 to 1930 ) , the segregated system of separate schools and public facilities known as `` Jim Crow laws '' , that lasted until the 1960s , and the widespread use of poll taxes and other methods to frequently deny black people of the right to vote or hold office until the 1960s . Since the late 1960s , black people have held many offices in Southern states , especially in the coastal states of Virginia and South Carolina . Many black people have also been elected or appointed as mayors and police chiefs in the metropolises of Memphis , Houston , Atlanta , and New Orleans , and serve in both the U.S. Congress and state legislatures . Historically , the South relied heavily on agriculture , and was highly rural until after 1945 . It has since become more industrialized and urban and has attracted national and international migrants . The American South is now among the fastest-growing areas in the United States . Houston is the largest city in the Southern United States . Sociological research indicates that Southern collective identity stems from political , demographic , and cultural distinctiveness from the rest of the United States . The region contains almost all of the Bible Belt , an area of high Protestant church attendance ( especially evangelical churches such as the Southern Baptist Convention ) and predominantly conservative , religion-influenced politics . Indeed , studies have shown that Southerners are more conservative than non-Southerners in several areas , including religion , morality , international relations and race relations . This is evident in both the region 's religious attendance figures and in the region 's usually strong support for the Republican Party in political elections since the 1960s , and especially since the 1990s . Apart from its climate , the living experience in the South increasingly resembles the rest of the nation . The arrival of millions of Northerners ( especially in major metropolitan areas and coastal areas ) and millions of Hispanics meant the introduction of cultural values and social norms not rooted in Southern traditions . Observers conclude that collective identity and Southern distinctiveness are thus declining , particularly when defined against `` an earlier South that was somehow more authentic , real , more unified and distinct '' . The process has worked both ways , however , with aspects of Southern culture spreading throughout a greater portion of the rest of the United States in a process termed `` Southernization '' . |