higher level anatomy physiology look internal structures functions organism ecology looks various organisms interrelate earth science earth science also known geoscience embracing term sciences related planet earth including geology geography geophysics geochemistry climatology glaciology hydrology meteorology oceanography although mining precious stones human interests throughout history civilization development related sciences economic geology mineralogy occur th century study earth particularly paleontology blossomed th


century growth disciplines geophysics th century led development theory plate tectonics similar effect earth sciences theory evolution biology earth sciences today closely linked petroleum mineral resources climate research environmental assessment remediation atmospheric sciences although sometimes considered conjunction earth sciences due independent development concepts techniques practices also fact wide range sub disciplines wing


atmospheric science also considered separate branch natural science field studies characteristics different layers atmosphere ground level edge space timescale study also varies day century sometimes field also includes study climatic patterns planets earth oceanography serious study oceans began early mid th century field natural science relatively young stand alone programs offer specializations subject though controversies remain categorization field


earth sciences interdisciplinary sciences separate field right modern workers field agree matured state paradigms practices chemistry structural formula molecule caffeine shows graphical representation atoms arranged constituting scientific study matter atomic molecular scale chemistry deals primarily collections atoms gases molecules crystals metals composition statistical properties transformations reactions materials studied chemistry also involves understanding properties interactions


individual atoms molecules use larger scale applications chemical processes studied directly laboratory using series often well tested techniques manipulating materials well understanding underlying processes chemistry often called central science role connecting natural sciences early experiments chemistry roots system alchemy set beliefs combining mysticism physical experiments science chemistry began develop work robert boyle discoverer gas antoine lavoisier developed theory


conservation mass discovery chemical elements atomic theory began systematize science researchers developed fundamental understanding states matter ions chemical bonds chemical reactions success science led complementary chemical industry plays significant role world economy physics orbitals hydrogen atom descriptions probability distributions electron bound proton mathematical descriptions standard problems quantum mechanics important branch physics physics embodies study fundamental constituents universe


systematic quantitative experimental testing observation source verification key historical developments physics include isaac newton 's theory universal gravitation classical mechanics understanding electricity relation magnetism einstein 's theories special general relativity development thermodynamics quantum mechanical model atomic subatomic physics field physics extremely broad include diverse studies quantum mechanics theoretical physics applied physics optics modern physics becoming increasingly specialized researchers tend focus particular area rather universalists like isaac


acquiring analyzing data mainly using basic principles physics theoretical astronomy oriented towards development computer analytical models describe astronomical objects phenomena uncrewed crewed spacecraft missions used image distant locations within solar system apollo view daedalus crater far side moon discipline science celestial objects phenomena originate outside earth 's atmosphere concerned evolution physics chemistry meteorology motion celestial objects well formation development


universe astronomy includes examination study modeling stars planets comets information used astronomers gathered remote observation although laboratory reproduction celestial phenomena performed molecular chemistry interstellar medium origins study celestial features phenomena traced back antiquity scientific methodology field began develop middle th century key factor galileo 's introduction telescope examine night sky detail mathematical treatment astronomy began


newton 's development celestial mechanics laws gravitation although triggered earlier work astronomers kepler th century astronomy developed formal science introduction instruments spectroscope photography along much improved telescopes creation professional observatories interdisciplinary studies distinctions natural science disciplines always sharp share many cross discipline fields physics plays significant role natural sciences represented astrophysics geophysics chemical physics biophysics likewise chemistry represented fields biochemistry


chemical biology geochemistry astrochemistry particular example scientific discipline draws upon multiple natural sciences environmental science field studies interactions physical chemical geological biological components environment particular regard effect human activities impact biodiversity sustainability science also draws upon expertise fields economics law social sciences comparable discipline oceanography draws upon similar breadth scientific disciplines oceanography sub categorized specialized cross disciplines physical oceanography marine biology marine


ecosystem large diverse marine biology divided many subfields including specializations particular species also subset cross disciplinary fields strong currents run counter specialization nature problems address put another way fields integrative application specialists one field key part dialog integrative fields example include nanoscience astrobiology complex system informatics materials science materials paradigm represented tetrahedron materials science relatively new interdisciplinary field deals


fail operate function intended causing personal injury damage property failure analysis latter key understanding example cause various aviation accidents many pressing scientific problems faced today due limitations materials available result breakthroughs field likely significant impact future technology basis materials science involves studying structure materials relating properties materials scientist knows


structure property correlation go study relative performance material certain application major determinants structure material thus properties constituent chemical elements processed final form characteristics taken together related laws thermodynamics kinetics govern material 's microstructure thus properties history scholars trace origins natural science far back pre literate human societies understanding natural world necessary survival people observed built


knowledge behavior animals usefulness plants food medicine passed generation generation primitive understandings gave way formalized inquiry around bc mesopotamian ancient egyptian cultures produced first known written evidence natural philosophy precursor natural science writings show interest astronomy mathematics aspects physical world ultimate aim inquiry nature 's workings cases religious mythological scientific tradition scientific inquiry also emerged


ancient china taoist alchemists philosophers experimented elixirs extend life cure ailments focused yin yang contrasting elements nature yin associated femininity coldness yang associated masculinity warmth five phases fire earth metal wood water described cycle transformations nature water turned wood turned fire burned ashes left fire earth using principles chinese philosophers doctors explored human anatomy characterizing organs predominantly yin yang


understood relationship pulse heart flow blood body centuries became accepted west little evidence survives ancient indian cultures around indus river understood nature perspectives may reflected vedas set sacred hindu texts reveal conception universe ever expanding constantly recycled reformed surgeons ayurvedic tradition saw health illness combination three humors wind bile phlegm healthy life result balance among


humors ayurvedic thought body consisted five elements earth water fire wind space ayurvedic surgeons performed complex surgeries developed detailed understanding human anatomy pre socratic philosophers ancient greek culture brought natural philosophy step closer direct inquiry cause effect nature bc although element magic mythology remained natural phenomena earthquakes eclipses explained increasingly context nature instead attributed angry gods thales miletus early philosopher lived bc explained


earthquakes theorizing world floated water water fundamental element nature th century bc leucippus early exponent atomism idea world made fundamental indivisible particles pythagoras applied greek innovations mathematics astronomy suggested earth spherical aristotelian natural philosophy bc ad aristotelian form father later socratic platonic thought focused ethics morals art attempt investigation physical world plato criticized pre socratic thinkers materialists anti religionists aristotle however


student plato lived bc paid closer attention natural world philosophy ''history animals'' described inner workings species including stingray catfish bee investigated chick embryos breaking open eggs observing various stages development aristotle 's works influential th century considered father biology pioneering work science also presented philosophies physics nature astronomy using inductive reasoning works ''physics'' ''meteorology''


painting raphael plato rejected inquiry natural philosophy religion student aristotle created body work natural world influenced generations scholars aristotle considered natural philosophy seriously predecessors approached theoretical branch science still inspired work ancient roman philosophers early st century ad including lucretius seneca pliny elder wrote treatises dealt rules natural world varying degrees depth many ancient roman neoplatonists rd th centuries also adapted


aristotle 's teachings physical world philosophy emphasized spiritualism early medieval philosophers including macrobius calcidius martianus capella also examined physical world largely cosmological cosmographical perspective putting forth theories arrangement celestial bodies heavens posited composed aether aristotle 's works natural philosophy continued translated studied amid rise byzantine empire abbasid caliphate byzantine empire john philoponus alexandrian aristotelian commentator christian theologian first questioned aristotle 's teaching physics unlike aristotle based


physics verbal argument philoponus instead relied observation argued observation rather resorting verbal argument introduced theory impetus john philoponus' criticism aristotelian principles physics served inspiration galileo galilei scientific revolution revival mathematics science took place time abbasid caliphate th century onward muslim scholars expanded upon greek indian natural philosophy words ''alcohol'' ''algebra'' ''zenith'' arabic roots medieval natural philosophy aristotle 's works greek natural philosophy reach


west middle th century works translated greek arabic latin development european civilization later middle ages brought advances natural philosophy european inventions horseshoe horse collar crop rotation allowed rapid population growth eventually giving way urbanization foundation schools connected monasteries cathedrals modern day france england aided schools approach christian theology developed sought answer questions nature subjects using logic approach however seen


held paris either publicly privately using aristotle 's books natural philosophy commentaries forbid pain ex communication late middle ages spanish philosopher dominicus gundissalinus translated treatise earlier persian scholar al farabi called ''on sciences'' latin calling study mechanics nature ''scientia naturalis'' natural science gundissalinus also proposed classification natural sciences work ''on division philosophy'' first detailed classification sciences based greek arab philosophy reach western europe


gundissalinus defined natural science science considering things unabstracted motion opposed mathematics sciences rely mathematics following al farabi separated sciences eight parts including physics cosmology meteorology minerals science plant animal science later philosophers made classifications natural sciences robert kilwardby wrote ''on order sciences'' th century classed medicine mechanical science along agriculture hunting theater defining natural science science deals bodies motion roger bacon english friar


philosopher wrote natural science dealt principle motion rest parts elements fire air earth water inanimate things made sciences also covered plants animals celestial bodies later th century catholic priest theologian thomas aquinas defined natural science dealing mobile beings things depend matter existence also definition wide agreement among scholars medieval times natural science bodies motion although


division inclusion fields including medicine music perspective philosophers pondered questions including existence vacuum whether motion could produce heat colors rainbows motion earth whether elemental chemicals exist atmosphere rain formed centuries end middle ages natural science often mingled philosophies magic occult natural philosophy appeared wide range forms treatises encyclopedias commentaries aristotle interaction natural philosophy christianity complex period


distance theology science works n't see one 's interpretation aristotle teaching faith wrote newton scientific revolution th th centuries natural philosophy underwent evolution beyond commentary aristotle early greek philosophy uncovered translated invention printing press th century invention microscope telescope protestant reformation fundamentally altered social context scientific inquiry evolved west christopher columbus 's discovery new world


changed perceptions physical makeup world observations copernicus tyco brahe galileo brought accurate picture solar system heliocentric proved many aristotle 's theories heavenly bodies false several th century philosophers including thomas hobbes john locke francis bacon made break past rejecting aristotle medieval followers outright calling approach natural philosophy superficial titles galileo 's work ''two new sciences'' johannes kepler 's ''new astronomy'' underscored atmosphere change took hold th century aristotle


dismissed favor novel methods inquiry natural world bacon instrumental popularizing change argued people use arts sciences gain dominion nature achieve wrote human life must endowed discoveries powers defined natural philosophy knowledge causes secret motions things enlarging bounds human empire effecting things possible bacon proposed scientific inquiry supported state fed collaborative research scientists vision unprecedented


scope ambition forms time natural philosophers came view nature increasingly mechanism could taken apart understood much like complex clock natural philosophers including isaac newton evangelista torricelli francesco redi conducted experiments focusing flow water measuring atmospheric pressure using barometer disproving spontaneous generation scientific societies scientific journals emerged spread widely printing press touching scientific revolution newton published ''the mathematical principles natural philosophy'' ''principia mathematica'' set groundwork physical laws


remained current th century modern scholars including andrew cunningham perry williams floris cohen argue natural philosophy properly called science genuine scientific inquiry began scientific revolution according cohen emancipation science overarching entity called 'natural philosophy one defining characteristic scientific revolution historians science including edward grant contend scientific revolution blossomed th th th centuries occurred principles learned exact sciences optics mechanics astronomy began applied questions


raised natural philosophy grant argues newton attempted expose mathematical basis nature immutable rules obeyed joined natural philosophy mathematics first time producing early work modern physics isaac newton widely regarded one influential scientists time scientific revolution began take hold th century represented sharp break aristotelian modes inquiry one principal advances use scientific method investigate nature data collected repeatable measurements


made experiments scientists formed hypotheses explain results experiments hypothesis tested using principle falsifiability prove disprove accuracy natural sciences continued called natural philosophy adoption scientific method took science beyond realm philosophical conjecture introduced structured way examining nature newton english mathematician physicist seminal figure scientific revolution drawing advances made astronomy copernicus brahe kepler newton derived universal law gravitation laws motion


charles augustin de coulomb alessandro volta michael faraday built upon newtonian mechanics exploring electromagnetism interplay forces positive negative charges electrically charged particles faraday proposed forces nature operated fields filled space idea fields contrasted newtonian construct gravitation simply action distance attraction objects nothing space intervene james clerk maxwell th century unified discoveries coherent theory electrodynamics using mathematical equations experimentation maxwell discovered space filled


charged particles could act upon medium transmission charged waves significant advances chemistry also took place scientific revolution antoine lavoisier french chemist refuted phlogiston theory posited things burned releasing phlogiston air joseph priestley discovered oxygen th century lavoisier discovered combustion result oxidation also constructed table elements invented modern chemical nomenclature formal biological science remained infancy th century focus


lay upon classification categorization natural life growth natural history led carl linnaeus whose taxonomy natural world still use linnaeus introduced scientific names species th century developments michelson morley experiment used disprove light propagated luminiferous aether th century concept superseded albert einstein 's special theory relativity th century study science come purview professionals institutions gradually acquired modern name ''natural


science'' term ' 'scientist'' coined william whewell review mary somerville 's ''on connexion sciences'' ref name holmes ref word enter general use nearly end century modern natural science present according famous textbook ''thermodynamics free energy chemical substances'' american chemist gilbert n lewis american physical chemist merle randall natural sciences contain three great branches blockquote aside logical mathematical sciences three great branches ''natural science'' stand apart reason


variety far reaching deductions drawn small number primary postulates mechanics electrodynamics thermodynamics blockquote today natural sciences commonly divided life sciences botany zoology physical sciences include physics chemistry astronomy earth sciences see also empiricism branches science list academic disciplines sub disciplines natural sciences cambridge tripos university cambridge https wwwinformationpvtcom nature sciencehtml nature science references bibliography url status dead archive url https webarchiveorg web http wwwbehaviorologyorg pdf definenatlsciencespdf archive date reading https webarchiveorg web http wwwbehaviorologyorg pdf definenatlsciencespdf defining natural sciences ledoux f defining natural sciences ''behaviorology today'' ''' ''' http hrstmitedu history recent science


technology https webarchiveorg web http scienciacom natural sciences contains updated information research natural sciences including biology geography applied life earth sciences https webarchiveorg web http scibooksorg reviews books natural science site contains previously published reviews books natural science plus selected essays timely topics natural science https webarchiveorg web http searchengrantcom scientific grant awards database contains details scientific research projects conducted past years https webarchiveorg web http esciencenewscom sources e science date science news aggregator major sources including universities branches science


'''business''' activity making one 's living making money producing buying selling products goods services simply put activity enterprise entered profit business name separate business entity owner means owner business responsible liable debts incurred business business acquires debts creditors go owner 's personal possessions business structure allow corporate tax rates proprietor personally taxed


income business term also often used colloquially lawyers public officials refer company company hand separate legal entity provides limited liability well corporate tax rates company structure complicated expensive set offers protection benefits owner forms forms business ownership vary jurisdiction several common entities exist '''sole proprietorship ''' sole proprietorship also known sole trader owned one person


operates benefit owner operates business alone may hire employees sole proprietor unlimited liability obligations incurred business whether operating costs judgments business assets business belong sole proprietor including example computer infrastructure inventory manufacturing equipment retail fixtures well real property owned sole proprietor '''partnership ''' partnership business owned two people forms partnerships partner unlimited liability debts incurred business


three prevalent types profit partnerships general partnerships limited partnerships limited liability partnerships '''corporation ''' owners corporation limited liability business separate legal personality owners corporations either government owned privately owned organize either profit nonprofit organizations privately owned profit corporation owned shareholders elect board directors direct corporation hire managerial staff privately owned profit corporation either privately held small group individuals


publicly held publicly traded shares listed stock exchange '''cooperative ''' often referred co op cooperative limited liability business organize profit profit cooperative differs corporation members shareholders share decision making authority cooperatives typically classified either consumer cooperatives worker cooperatives cooperatives fundamental ideology economic democracy '''limited liability companies''' llc limited liability partnerships specific types business organization protect owners shareholders business failure business separate legal entity


certain legal protections contrast unincorporated businesses persons working usually protected '''franchises ''' franchise system entrepreneurs purchase rights open run business larger corporation franchising united states widespread major economic powerhouse one twelve retail businesses united states franchised million people employed franchised business '''a company limited guarantee ''' commonly used companies formed non commercial purposes clubs charities


members guarantee payment certain usually nominal amounts company goes insolvent liquidation otherwise economic rights relation company type company common england company limited guarantee may without share capital '''a company limited shares ''' common form company used business ventures specifically limited company company liability shareholder limited amount individually invested corporations common example limited company ref name black 's black 's law


lee dictionary second pocket edition bryan garner editor west ref type company common england many english speaking countries company limited shares may publicly traded company privately held company '''a company limited guarantee share capital ''' hybrid entity usually used company formed non commercial purposes activities company partly funded investors expect return type company may longer formed uk although provisions still exist law


exist '''a limited liability company ''' company statutorily authorized certain states characterized limited liability management members managers limitations ownership transfer ie llc ref name black 's llc structure called hybrid combines characteristics corporation partnership sole proprietorship like corporation limited liability members company like partnership flow taxation members must dissolved upon death bankruptcy member '''an unlimited company without share capital ''' hybrid entity


company liability members shareholders debts company limited case doctrine veil incorporation apply ''less common types companies '' '''companies formed letters patent ''' corporations letters patent ''corporations sole'' companies term commonly understood today '''charter corporations ''' passing modern companies legislation types companies relatively rare except old companies still survive still many particularly


many british banks modern societies fulfill quasi regulatory function example bank england corporation formed modern charter '''statutory companies ''' relatively rare today certain companies formed private statute passed relevant jurisdiction note ltd company 's name signifies limited company plc public limited company indicates shares widely held legal parlance owners company normally referred members company limited unlimited shares formed incorporated share capital


shareholders company limited guarantee guarantors offshore jurisdictions created special forms offshore company bid attract business jurisdictions examples include segregated portfolio companies restricted purpose companies however many many sub categories types company formed various jurisdictions world companies also sometimes distinguished '''public companies''' '''private companies''' legal regulatory purposes public companies companies whose shares publicly traded often although always stock exchange imposes listing requirements listing rules


issued shares trading shares future issue shares help bolster reputation exchange particular market exchange private companies publicly traded shares often contain restrictions transfers shares jurisdictions private companies maximum numbers shareholders parent company company owns enough voting stock another firm control management operations influencing electing board directors second company deemed subsidiary parent company definition parent company differs


jurisdiction definition normally defined way laws dealing companies jurisdiction classifications agriculture domestication fish animals livestock well lumber oil mining businesses extract natural resources raw materials wood petroleum natural gas ores plants minerals service businesses offer intangible goods services typically charge labor services provided government consumers businesses interior decorators beauticians hair stylists make artists tanning salons laundromats dry cleaners pest controllers service businesses financial services


businesses include banks brokerage firms credit unions credit cards insurance companies asset investment companies private equity firms private equity funds real estate investment trusts sovereign wealth funds pension funds mutual funds index funds hedge funds stock exchanges companies generate profits investment management capital transportation businesses railways airlines shipping companies deliver goods individuals destinations fee utilities produce public services water electricity waste management sewage treatment industries usually operated charge public government entertainment companies mass media agencies


generate profits primarily sale intellectual property include film studios production houses mass media companies cable television networks online digital media agencies talent agencies mobile media outlets newspapers book magazine publishing houses sports organizations involved producing facilitating promoting organizing activity experience business enterprise focused sports make profits selling goods services sports related industrial manufacturers produce products either raw materials component parts export finished products profit include tangible goods cars buses medical


devices glass aircraft real estate businesses sell invest construct develop properties including land residential homes buildings retailers wholesalers distributors act middlemen get goods produced manufacturers intended consumers make profits marking prices stores catalog companies distributors retailers activities accounting accounting measurement processing communication financial information economic entities ref name np ref businesses corporations modern field established italian mathematician luca pacioli ref name jkdiwan ref accounting


called language business ref name wharton language ref measures results organization 's economic activities conveys information variety users including investors creditors management regulators ref name uw dept ref practitioners accounting known accountants terms accounting financial reporting often used synonyms finance finance field deals study money investments includes dynamics assets liabilities time conditions different degrees uncertainty risk context business management finance deals


problems ensuring firm safely profitably carry operational financial objectives ie sufficient cash flow ongoing upcoming operational expenses service maturing short term debt repayments scheduled long term debt payments finance also deals ''long term'' objective maximizing value business also balancing risk profitability includes interrelated questions capital investment businesses projects invest capital structure deciding mix funding used dividend policy


excess capital manufacturing manufacturing production merchandise use sale using labour machines tools chemical biological processing formulation term may refer range human activity handicraft high tech commonly applied industrial production raw materials transformed finished goods large scale marketing marketing defined american marketing association '' activity set institutions processes creating communicating delivering exchanging offerings value customers clients partners society


manage since defining feature research researchers know advance exactly accomplish desired result safety injuries cost businesses billions dollars annually studies shown company acceptance implementation comprehensive safety health management systems reduce incidents insurance costs workers' compensation claims new technologies like wearable safety devices available online safety training continue developed encourage employers invest protection beyond canary coal mine reduce cost businesses protecting employees sales


sales activity related selling number goods services sold given time period sales often integrated lines business key companies' success management efficient effective operation business study subject called management major branches management financial management marketing management human resource management strategic management production management operations management service management information technology management owners may manage businesses employ managers whether owners employees


managers administer three primary components business' value financial resources capital tangible resources human resources resources administered least six functional areas legal contracting manufacturing service production marketing accounting financing human resources restructuring state enterprises recent decades states modeled assets enterprises business enterprises example people 's republic china modeled state owned enterprises company type management system many state institutions enterprises china russia transformed joint stock companies part shares listed


public stock markets business process management bpm holistic management approach focused aligning aspects organization wants needs clients bpm attempts improve processes continuously therefore described process optimization process argued bpm enables organizations efficient effective capable change functionally focused traditional hierarchical management approach organization regulation access date march ref legal jurisdictions specify forms ownership business take creating body commercial law type major


factors affecting business organized usually '''the size scope business firm''' structure management ownership broadly analyzed theory firm generally smaller business flexible larger businesses wider ownership formal structures usually tend organized corporations less often partnerships addition business wishes raise money stock market owned wide range people often required adopt specific legal form '''the sector


informal mechanisms ref name ref particular contractual relational governance help mitigate opportunism well support communication information sharing ref name many businesses operated separate entity corporation partnership either formed without limited liability legal jurisdictions allow people organize entity filing certain charter documents relevant secretary state equivalent complying certain ongoing obligations relationships legal rights shareholders limited partners members governed partly charter documents partly law


jurisdiction entity organized generally speaking shareholders corporation limited partners limited partnership members limited liability company shielded personal liability debts obligations entity legally treated separate person means unless misconduct owner 's possessions strongly protected law business succeed two individuals business together failed organize specialized form vehicle treated general partnership terms


profits owners individuals include dividends income complete personal tax returns point second layer income tax imposed countries laws treat small corporations differently large ones may exempt certain legal filing requirements labor laws simplified procedures specialized areas simplified advantageous slightly different tax treatment going public process known initial public offering ipo means part business owned members public


requires organization distinct entity disclose information public adhering tighter set laws procedures public entities corporations sold shares increasingly also public llc 's sell units sometimes also called shares exotic entities well example real estate investment trusts us unit trusts uk general partnership cannot go public commercial law offices los angeles downtown financial district detailed well established body rules evolved


long period time applies commercial transactions need regulate trade commerce resolve business disputes helped shape creation law courts code hammurabi dates back bc example contains provisions relate among matters shipping costs dealings merchants brokers word corporation derives latin ''corpus'' meaning body maurya empire iron age india accorded legal rights business entities many countries difficult compile laws affect business single reference


may also require special licenses taxes operate business businesses subject ongoing special regulation example public utilities investment securities banking insurance broadcasting aviation health care providers environmental regulations also complex affect many businesses capital mexican stock exchange paseo de la reforma mexico city businesses need raise money called capital sometimes offer securities sale capital may raised private means initial public offering ipo stock exchange ways major stock exchanges include shanghai


stock exchange singapore exchange hong kong stock exchange new york stock exchange nasdaq usa london stock exchange uk tokyo stock exchange japan bombay stock exchange india countries capital markets least one businesses gone public subject regulations concerning internal governance executive officers' compensation determined information disclosed shareholders public united states regulations primarily implemented enforced united states securities exchange commission sec western nations comparable regulatory


employee benefit plans food drug regulation intellectual property law copyrights patents trademarks telecommunications law financing types capital sourcing include crowdsourcing internet venture capital bank loans debentures intellectual property businesses often important intellectual property needs protection competitors company stay profitable could require patents copyrights trademarks preservation trade secrets businesses names logos similar branding techniques could benefit trademarking patents copyrights united states largely governed federal law trade secrets trademarking mostly


matter state law nature intellectual property business needs protection every jurisdiction concerned competitors many countries signatories international treaties concerning intellectual property thus companies registered countries subject national laws bound treaties order protect trade secrets companies may require employees sign noncompete clauses impose limitations employee 's interactions stakeholders competitors trade union trade union labor union organization workers come together achieve common


goals protecting integrity trade improving safety standards achieving higher pay benefits health care retirement increasing number employees employer assigns complete work better working conditions trade union leadership bargains employer behalf union members rank file members negotiates labor contracts collective bargaining employers common purpose associations unions maintaining improving conditions employment ref name webb ch ref may include negotiation wages work rules complaint procedures rules governing


hiring firing promotion workers benefits workplace safety policies see also references external links entrepreneurship main topic articles


'''geochemistry''' science uses tools principles chemistry explain mechanisms behind major geological systems earth 's crust oceans ref name albarede realm geochemistry extends beyond earth encompassing entire solar system ref name cosmo made important contributions understanding number processes including mantle convection formation planets origins granite basalt ref name albarede integrated field chemistry geology history victor goldschmidt term ''geochemistry'' first used swiss german chemist christian friedrich sch nbein


comparative geochemistry ought launched geochemistry become geology mystery genesis planets inorganic matter may revealed ref name buildingbridges ref however rest century common term chemical geology little contact geologists chemists ref name buildingbridges geochemistry emerged separate discipline major laboratories established starting united states geological survey usgs began systematic surveys chemistry rocks minerals chief usgs chemist frank wigglesworth clarke noted elements generally decrease


abundance atomic weights increase summarized work elemental abundance ''the data geochemistry'' ref name buildingbridges ref name mcsween ref composition meteorites investigated compared terrestrial rocks early oliver c farrington hypothesised although differences relative abundances still ref name buildingbridges beginnings field cosmochemistry contributed much know formation earth solar system ref name cornell ref early th century max von laue william l bragg showed x ray scattering


could used determine structures crystals victor goldschmidt associates university oslo applied methods many common minerals formulated set rules elements grouped goldschmidt published work series ''geochemische verteilungsgesetze der elemente'' geochemical laws distribution elements ref name mcsween research manfred schidlowski around year concerned biochemistry early earth focus isotope biogeochemistry evidence earliest life processes precambrian subfields


subfields geochemistry aqueous geochemistry studies role various elements watersheds including copper sulfur mercury elemental fluxes exchanged atmospheric terrestrial aquatic interactions biogeochemistry field study focusing effect life chemistry earth cosmochemistry includes analysis distribution elements isotopes cosmos ref name cosmo ref isotope geochemistry involves determination relative absolute concentrations elements isotopes earth earth 's surface organic geochemistry study role processes compounds derived


living living organisms photogeochemistry study light induced chemical reactions occur may occur among natural components earth 's surface regional geochemistry includes applications environmental hydrological mineral exploration studies chemical elements building blocks materials chemical elements identified atomic number z number protons nucleus element one value n number neutrons nucleus sum mass number roughly equal atomic mass atoms


atomic number different neutron numbers called isotopes given isotope identified letter element preceded superscript mass number example two common isotopes chlorine sup sup cl sup sup cl known combinations z n stable however unstable isotopes occur nature geochemistry stable isotopes used trace chemical pathways reactions radioactive isotopes primarily used date samples ref name mcsween chemical behavior atom affinity


mg ca dominate earth 's crust forming silicates oxides ''siderophile'' elements fe co ni pt os affinity iron tend concentrate core ''chalcophile'' elements cu ag zn pb form sulfides ''atmophile'' elements n h noble gases dominate atmosphere within group elements refractory remaining stable high temperatures others volatile evaporating easily heating separate ref name albarede ref ref name mcsween differentiation mixing chemical composition earth bodies determined two opposing processes differentiation


mixing earth 's mantle differentiation occurs mid ocean ridges partial melting refractory materials remaining base lithosphere remainder rises form basalt oceanic plate descends mantle convection eventually mixes two parts together erosion differentiates granite separating clay ocean floor sandstone edge continent dissolved minerals ocean waters metamorphism anatexis partial melting crustal rocks mix elements together ocean biological organisms cause chemical differentiation dissolution organisms


wastes mix materials ref name albarede fractionation major source differentiation fractionation unequal distribution elements isotopes result chemical reactions phase changes kinetic effects radioactivity ref name albarede largest scale ''planetary differentiation'' physical chemical separation planet chemically distinct regions example terrestrial planets formed iron rich cores silicate rich mantles crusts earth 's mantle primary source chemical differentiation partial melting particularly near mid ocean ridges occur solid heterogeneous solid solution part


melt separated solid process known ''equilibrium'' ''batch'' melting solid melt remain equilibrium moment melt removed ''fractional'' ''rayleigh'' melting removed continuously isotopic fractionation mass dependent mass independent forms molecules heavier isotopes lower ground state energies therefore stable result chemical reactions show small isotope dependence heavier isotopes preferring species compounds higher oxidation state phase changes heavier isotopes tend concentrate heavier phases ref


name kendall ref mass dependent fractionation largest light elements difference masses larger fraction total mass ref name hoefs ref ratios isotopes generally compared standard example sulfur four stable isotopes two common sup sup sup sup ref name hoefs ratio concentrations sup sup sup sup reported math delta mathrm left frac r r mathrm right math ratio standard differences small ratio multiplied make parts per thousand referred parts per mil represented symbol ref


breaking energy bonds addition previously mentioned factors environment species organism large effect fractionation ref name kendall cycles variety physical chemical processes chemical elements change concentration move around called ''geochemical cycles'' understanding changes requires detailed observation theoretical models chemical compound element isotope concentration function position time impractical model full variability instead approach borrowed chemical engineering ref name albarede geochemists


average concentration regions earth called ''geochemical reservoirs'' choice reservoir depends problem example ocean may single reservoir split multiple reservoirs ref name lasaga ref type model called ''box model'' reservoir represented box inputs outputs ref name albarede ref name lasaga geochemical models generally involve feedback simplest case linear cycle either input output reservoir proportional concentration example salt removed ocean formation evaporites given constant


rate evaporation evaporite basins rate removal salt proportional concentration given component input reservoir constant output constant ''mass balance'' equation numblk math frac c kc math expresses fact change mass must balanced changes input output time scale k system approaches steady state ''a'' ''k'' ' 'residence time'' defined math tau mathrm res c text steady


c text steady math input output rates example steady state input output rates equal ''k'' ref name lasaga input output rates nonlinear functions may still closely balanced time scales much greater residence time otherwise large fluctuations case system always close steady state lowest order expansion mass balance equation lead linear equation like equation systems one


input output depend resulting feedback tends maintain steady state external forcing perturbs system return steady state time scale ref name lasaga abundance elements solar system cid ref composition solar system similar many stars aside small anomalies assumed formed solar nebula uniform composition composition sun 's photosphere similar rest solar system composition


volatiles h c n group elements li b destroyed nucleosynthesis sun ref name mcsween ref name palme latter group ci chondrites considered better match composition early solar system moreover chemical analysis ci chondrites accurate photosphere generally used source chemical abundance despite rareness five recovered earth ref name palme giant planets cutaways illustrating models interiors giant planets planets solar system divided


two groups four inner planets terrestrial planets mercury venus earth mars relatively small sizes rocky surfaces four outer planets giant planets dominated hydrogen helium lower mean densities subdivided gas giants jupiter saturn ice giants uranus neptune large icy cores direct information composition giant planets spectroscopy since jupiter known contain hydrogen methane ammonium interferometry greatly increased


compared solar composition ne factor surprising result since noble gases elements c n enhanced factors oxygen also depleted attributed unusually dry region galileo sampled ref name fortney spectroscopic methods penetrate atmospheres jupiter saturn depths pressure equal bar approximately earth 's atmospheric pressure sea level ref name lewis galileo probe penetrated bars ref name fortney small fraction planet


expected reach pressures mbar constrain composition interior thermodynamic models constructed using information temperature infrared emission spectra equations state likely compositions ref name lewis high pressure experiments predict hydrogen metallic liquid interior jupiter saturn uranus neptune remains molecular state ref name lewis estimates also depend models formation planets condensation presolar nebula would result gaseous planet composition sun planets could also


formed solid core captured nebular gas ref name lewis current models four giant planets cores rock ice roughly size proportion hydrogen helium decreases earth masses jupiter saturn uranus neptune ref name lewis thus gas giants primarily composed hydrogen helium ice giants primarily composed heavier elements c n primarily form water methane ammonia surfaces cold enough molecular hydrogen


liquid much planet likely hydrogen ocean overlaying one heavier compounds outside core jupiter mantle liquid metallic hydrogen atmosphere molecular hydrogen helium metallic hydrogen mix well helium saturn may form separate layer metallic hydrogen ref name lewis terrestrial planets terrestrial planets believed come nebular material giant planets lost lighter elements different histories planets closer sun might expected


higher fraction refractory elements later stages formation involved collisions large objects orbits sampled different parts solar system could little systematic dependence position ref name anderson ref direct information mars venus mercury largely comes spacecraft missions using gamma ray spectrometers composition crust mars measured mars odyssey orbiter crust venus venera missions venus ref name anderson crust mercury ''messenger'' spacecraft additional information mars comes meteorites landed earth


shergottites nakhlites chassignites collectively known snc meteorites ref name kieffer ref abundances also constrained masses planets internal distribution elements constrained moments inertia ref name mcsween planets condensed solar nebula much details composition determined fractionation cooled phases condense fall five groups first condense materials rich refractory elements ca al followed nickel iron magnesium silicates kelvins k fes volatile rich metals


silicates form fourth group fifth group feo enter magnesium silicates ref name morgan ref compositions planets moon ''chondritic'' meaning within group ratios elements carbonaceous chondrites ref name mcsween estimates planetary compositions depend model used ''equilibrium condensation'' model planet formed ''feeding zone'' compositions solids determined temperature zone thus mercury formed k iron remained pure metallic form little magnesium


silicon solid form venus k magnesium silicon condensed earth k contains fes silicates mars k feo incorporated magnesium silicates greatest problem theory volatiles would condense planets would atmospheres earth atmosphere ref name mcsween ''chondritic mixing'' models compositions chondrites used estimate planetary compositions example one model mixes two components one composition c chondrites one refractory components c chondrites ref name mcsween


another model abundances five fractionation groups estimated using index element group refractory group uranium used iron second ratios potassium thallium uranium next two molar ratio feo feo mgo last using thermal seismic models along heat flow density fe constrained within percent earth venus mercury u constrained within earth abundance planets based educated guesses one difficulty model


may significant errors prediction volatile abundances volatiles partially condensed ref name morgan ref name mcsween earth 's crust common rock constituents nearly oxides chlorides sulfides fluorides important exceptions total amount rock usually much less f w clarke calculated little earth 's crust consists oxygen occurs principally combination oxides chief silica alumina iron oxides various carbonates calcium carbonate magnesium carbonate


sodium carbonate potassium carbonate silica functions principally acid forming silicates commonest minerals igneous rocks nature computation based analyses numerous kinds rocks clarke arrived following average percentage composition earth 's crust sio sub sub al sub sub sub sub fe sub sub sub sub feo mgo cao na sub sub k sub sub h sub sub tio sub sub p sub sub sub sub total constituents occur small quantities usually much less ref name eb oxides combine haphazard way example potash potassium carbonate soda sodium carbonate combine


produce feldspars cases may take forms nepheline leucite muscovite great majority instances found feldspar phosphoric acid lime calcium carbonate forms apatite titanium dioxide ferrous oxide gives rise ilmenite part lime forms lime feldspar magnesium carbonate iron oxides silica crystallize olivine enstatite alumina lime form complex ferromagnesian silicates pyroxenes amphiboles biotites chief excess silica required neutralize bases separate


quartz excess alumina crystallizes corundum must regarded general tendencies possible rock analysis say approximately minerals rock contains numerous exceptions rule ref name eb mineral constitution except acid siliceous igneous rocks containing greater silica known felsic rocks quartz abundant igneous rocks basic rocks containing silica less rare contain much silicon referred mafic rocks magnesium iron average silica


low olivine may expected silica present greater quantity ferromagnesian minerals augite hornblende enstatite biotite occur rather olivine unless potash high silica relatively low leucite present leucite occur free quartz nepheline likewise usually found rocks much soda comparatively little silica high alkalis soda bearing pyroxenes amphiboles may present lower percentage silica alkali 's greater prevalence plagioclase feldspar contracted soda potash feldspar ref name eb earth 's crust composed


silicate minerals abundance earth follows plagioclase feldspar alkali feldspar quartz pyroxene amphiboles micas clay minerals remaining silicate minerals make another earth 's crust earth composed non silicate minerals carbonates oxides sulfides determining factor namely physical conditions attending consolidation plays whole smaller part yet means negligible certain minerals practically confined deep seated intrusive rocks eg microcline muscovite diallage leucite rare plutonic masses many


minerals special peculiarities microscopic character according whether crystallized depth near surface eg hypersthene orthoclase quartz curious instances rocks chemical composition consisting entirely different minerals eg hornblendite gran norway contains hornblende composition camptonites locality contain feldspar hornblende different variety connection may repeat said corrosion porphyritic minerals igneous rocks rhyolites trachytes early crystals hornblende


low percentages silica much iron magnesia except last practically rocks contain felspars feldspathoid minerals acid rocks common feldspars orthoclase perthite microcline oligoclase much silica alkalis mafic rocks labradorite anorthite bytownite prevail rich lime poor silica potash soda augite common ferromagnesian mafic rocks biotite hornblende whole frequent felsic rocks ref name eb class wikitable rowspan common minerals felsic colspan intermediate mafic ultramafic


contain leucite nepheline either partly wholly replacing felspar included table essentially intermediate mafic character might consequence regard varieties syenite diorite gabbro etc feldspathoid minerals occur indeed many transitions syenites ordinary type nepheline leucite syenite gabbro dolerite theralite essexite many minerals develop alkali rocks uncommon elsewhere convenient purely formal classification like outlined treat whole assemblage


distinct series ref name eb class wikitable nepheline leucite bearing rocks common minerals alkali feldspar nepheline leucite augite hornblend biotite soda lime feldspar nepheline leucite augite hornblende olivine nepheline leucite augite hornblende olivine plutonic type nepheline syenite leucite syenite nepheline porphyry essexite theralite ijolite missourite effusive type lavas phonolite leucitophyre tephrite basanite nepheline basalt leucite basalt classification based essentially mineralogical constitution igneous rocks chemical distinctions different groups though implied relegated


subordinate position admittedly artificial grown growth science still adopted basis minute subdivisions erected subdivisions means equal value syenites example peridotites far less important granites diorites gabbros moreover effusive andesites always correspond plutonic diorites partly also gabbros different kinds rock regarded aggregates minerals pass gradually one another transitional types common often


important receive special names quartz syenites nordmarkites may interposed granite syenite tonalites adamellites granite diorite monzonites syenite diorite norites hyperites diorite gabbro ref name eb ref trace metals ocean trace metals readily form complexes major ions ocean including hydroxide carbonate chloride chemical speciation changes depending whether environment oxidized reduced benjamin defines complexes metals one type ligand water mixed ligand complexes cases


ligand contains one ' 'donor'' atom forming strong complexes also called chelates ligand chelator one common chelators edta ethylenediaminetetraacetic acid replace six molecules water form strong bonds metals plus two charge ref name benjamin ref stronger complexation lower activity free metal ion observed one consequence lower reactivity complexed metals compared concentration free metal chelation tends stabilize metals aqueous solution instead solids ref name benjamin concentrations


trace metals cadmium copper molybdenum manganese rhenium uranium vanadium sediments record redox history oceans within aquatic environments cadmium ii either form cdcl sup sup sub aq sub oxic waters cds reduced environment thus higher concentrations cd marine sediments may indicate low redox potential conditions past copper ii prevalent form cucl sup sup aq within oxic environments cus cu sub sub within reduced environments reduced seawater environment leads two possible oxidation states copper cu cu ii molybdenum present mo vi oxidation state moo sub sub sup sup sub aq sub oxic


environments mo v mo iv present reduced environments forms moo sub sub sup sup sub aq sub mos sub sub rhenium present vii oxidation state reo sub sub sup sup within oxic conditions reduced iv may form reo sub sub res sub sub uranium oxidation state vi uo sub sub co sub sub sub sub sup sup aq found reduced form uo sub sub vanadium several forms oxidation state v v hvo sub sub sup sup h sub sub vo sub sub sup sup reduced forms include vo sub sub sup sup vo oh sub sub sup sup v oh sub sub relative dominance species depends ph water column ocean deep lakes vertical profiles dissolved trace


metals characterized following ''conservative type'' ''nutrient type'' ' 'scavenged type'' distributions across three distributions trace metals different residence times used varying extents planktonic microorganisms trace metals conservative type distributions high concentrations relative biological use one example trace metal conservative type distribution molybdenum residence time within oceans around x sup sup years generally present molybdate anion moo sub sub sup sup molybdenum interacts weakly particles displays almost uniform vertical profile ocean relative abundance molybdenum


interactions particles well short residence time ocean residence times scavenged type trace metals around years concentrations metals highest around bottom sediments hydrothermal vents rivers aluminium atmospheric dust provides greatest source external inputs ocean ref name bruland iron copper show hybrid distributions ocean influenced recycling intense scavenging iron limiting nutrient vast areas oceans found high abundance along manganese near hydrothermal vents many iron precipitates


found mostly forms iron sulfides oxidized iron oxyhydroxide compounds concentrations iron near hydrothermal vents one million times concentrations found open ocean ref name bruland using electrochemical techniques possible show bioactive trace metals zinc cobalt cadmium iron copper bound organic ligands surface seawater ligand complexes serve lower bioavailability trace metals within ocean example copper may toxic open ocean phytoplankton bacteria form organic complexes formation complexes reduces concentrations


scholastic th century image university lecture '''scholasticism''' medieval school philosophy employed critical method philosophical analysis predicated upon latin catholic theistic curriculum dominated teaching medieval universities europe originated within christian monastic schools basis earliest european universities rise scholasticism closely associated schools flourished italy france spain england scholasticism much philosophy theology method learning places strong emphasis

Humanities
History
Philosophical history
Scholasticism


dialectical reasoning extend knowledge inference resolve contradictions scholastic thought also known rigorous conceptual analysis careful drawing distinctions classroom writing often takes form explicit disputation topic drawn tradition broached form question oppositional responses given counterproposal argued oppositional arguments rebutted emphasis rigorous dialectical method scholasticism eventually applied many fields study ref name cambridgedict patte daniel ''the cambridge dictionary christianity'' ed daniel patte new york cambridge university press


regent master ' 'studium provinciale'' santa sabina rome forerunner pontifical university saint thomas aquinas ''angelicum'' important work scholastic tradition carried well past aquinas 's time instance francisco su rez luis de molina also among lutheran reformed thinkers etymology terms scholastic scholasticism derive latin word '''' latinized form greek '''' adjective derived '''' school ''scholasticus'' means pertaining schools scholastics roughly schoolmen history foundations christian


schools every abbey empire schools name ' 'scholasticism'' derived became centers medieval learning period knowledge ancient greek vanished west except ireland teaching use widely dispersed monastic schools irish scholars considerable presence frankish court renowned learning ref name stanforderiugena ref among johannes scotus eriugena one founders scholasticism ref name gothic abelard nbsp together john scotus erigena th century lanfranc anselm canterbury th century


one founders scholasticism ref eriugena significant irish intellectual early monastic period outstanding philosopher terms originality ref name stanforderiugena considerable familiarity greek language translated many works latin affording access cappadocian fathers greek theological tradition ref name stanforderiugena three founders scholasticism th century scholars peter abelard archbishop lanfranc canterbury archbishop anselm canterbury ref name gothic period saw beginning 'rediscovery' many greek works lost latin west early


th century scholars spain begun gather translated texts latter half century began transmitting rest europe successful burst reconquista th century spain opened even christian scholars europeans encountered islamic philosophy opened wealth arab knowledge mathematics astronomy ref name institutions grant edward emeritus edward grant foundations modern science middle ages religious institutional intellectual contexts cambridge university press ref scholars adelard bath traveled spain sicily translating


works astronomy mathematics including first complete translation euclid 's ''elements'' latin time anselm laon systematized production gloss scripture followed rise prominence dialectic middle subject medieval trivium work abelard peter lombard produced collection ''sentences'' opinions church fathers authorities high scholasticism th early th centuries generally seen high period scholasticism early th century witnessed culmination recovery greek philosophy schools


translation grew italy sicily eventually rest europe powerful norman kings gathered men knowledge italy areas courts sign prestige william moerbeke 's translations editions greek philosophical texts middle half thirteenth century helped form clearer picture greek philosophy particularly aristotle given arabic versions previously relied edward grant writes structure arabic language radically different latin arabic versions


aristotelian sources derived east moorish spain great representatives dominican thinking period albertus magnus especially thomas aquinas whose artful synthesis greek rationalism christian doctrine eventually came define catholic philosophy aquinas placed emphasis reason argumentation one first use new translation aristotle 's metaphysical epistemological writing significant departure neoplatonic augustinian thinking dominated much early scholasticism aquinas showed possible incorporate much philosophy aristotle without falling


errors commentator averroes spanish scholasticism late scholasticism lutheran scholasticism reformed scholasticism following reformation calvinists largely adopted scholastic method theology differing regarding sources authority content theology neo scholasticism revival development second half th century medieval scholastic philosophy sometimes called neo thomism ref name ref thomistic scholasticism j weisheipl op emphasizes within dominican order thomistic scholasticism continuous since time aquinas thomism always alive dominican order small


instrument critique contemporary thought due suspicion attempts harmonize aquinas non thomistic categories assumptions scholastic thomism sometimes called according philosophers like edward feser strict observance thomism discussion recent current thomistic scholasticism found ''la metafisica di san tommaso d'aquino e suoi interpreti'' includes figures sofia vanni rovighi cornelio fabro carlo giacon tomas tyn op abelardo lobato op leo elders giovanni ventimiglia among others fabro


particular emphasizes aquinas' originality especially respect ''actus essendi'' act existence finite beings participating scholars involved progetto tommaso seek establish objective universal reading aquinas' texts thomistic scholasticism english speaking world went decline thomistic revival spearheaded jacques maritain tienne gilson others diminished influence partly branch thomism become quest understand historical aquinas second vatican council analytical


best way achieve replicating discovery process ''modus inveniendi'' scholasticists would choose book renowned scholar ''auctor'' author subject investigation reading thoroughly critically disciples learned appreciate theories author documents related book would referenced church councils papal letters anything else written subject ancient contemporary points disagreement contention multiple sources would written individual sentences snippets text known sententiae


sources points disagreement laid series dialectics two sides argument would made whole would found agreement contradictory course sometimes opinions would totally rejected new positions proposed done two ways first philological analysis words examined argued multiple meanings also considered ''auctor'' might intended certain word mean something different ambiguity could used find common ground


two otherwise contradictory statements second logical analysis relied rules formal logic known time show contradictions exist subjective reader ref name westintel colish marcia l ''medieval foundations western intellectual tradition '' yale university press ref scholastic instruction scholastic instruction consisted several elements first ''lectio'' teacher would read authoritative text followed commentary questions permitted followed ''meditatio'' meditation reflection students


reflected appropriated text finally ''quaestio'' students could ask questions ''quaestiones'' might occurred ''meditatio'' eventually discussion ''questiones'' became method inquiry apart ''lectio'' independent authoritative texts ''disputationes'' arranged resolve controversial ''quaestiones'' questions disputed ordinarily announced beforehand students could propose question teacher unannounced ' 'disputationes de quodlibet'' case teacher responded students rebutted following day teacher used notes taken disputation summarised arguments presented


final position riposting rebuttals ref name westintel ''quaestio'' method reasoning initially used especially two authoritative texts seemed contradict one another two contradictory propositions would considered form either question part question would approved ' 'sic'' denied ''non'' arguments position taken would presented turn followed arguments position finally arguments would refuted method forced scholars consider opposing viewpoints defend arguments see also ''actus primus'' allegory


middle ages aristotelianism casuistry history science middle ages list scholastic philosophers medieval philosophy nominalism pardes jewish exegesis renaissance th century scotism references primary sources secondary sources decock w '' https brillcom view title theologians contract law moral transformation ius commune c '' leiden boston brill nijhoff fryde e ''the early palaeologan renaissance'' brill gracia j g noone b eds ''a companion philosophy middle ages'' london blackwell mcgrade ed ''the cambridge companion medieval philosophy'' cambridge cambridge university


press reading trueman carl r r scott clark ''jt eds'' ''protestant scholasticism essays reassessment'' carlisle eng paternoster press external links http scholasticonfr scholasticon jacob schmutz http capricornbcedu siepm medieval philosophy electronic resources http wwwbritannicacom eb article scholasticism scholasticism ''encyclop dia britannica'' online http wwwndedu departments maritain etext scholas htm ''scholasticism'' joseph rickaby pp https archiveorg details scholasticism rickgoog also googlebooks http wwwnewadventorg cathen ahtm scholasticism catholic encyclopedia https webarchiveorg web http diryahoocom arts humanities philosophy scholasticism yahoo directory category scholasticism http webmathsunsweduau jim scholasticshtml genius scholastics orbit aristotle article james franklin influence scholasticism later thought http jameshannamcom medievalsciencehtm medieval philosophy universities church james hannam


illustration industry showing four industrial revolutions brief english description '''industrial sociology''' recently crucial research area within field '' 'sociology work''' examines direction implications trends technological change globalization labour markets work organization managerial practices employment relations extent trends intimately related changing patterns inequality modern societies changing experiences individuals families ways workers challenge resist make contributions patterning work shaping work institutions

Social science
Sociology
Industrial sociology


labour process theory one branch industrial sociology labour process theory lpt harry braverman wrote ''labor monopoly capital'' provided critical analysis scientific management book analysed capitalist productive relations marxist perspective following marx braverman argued work within capitalist organizations exploitative alienating therefore workers coerced servitude braverman pursuit capitalist interests time ultimately leads deskilling routinization worker taylorist work design ultimate embodiment tendency braverman demonstrated several mechanisms control


factory blue collar clerical white collar labour force key contribution deskilling thesis braverman argued capitalist owners managers incessantly driven deskill labour force lower production costs ensure higher productivity deskilled labour cheap easy control due workers' lack direct engagement production process turn work becomes intellectually emotionally unfulfilling lack capitalist reliance human skill reduces need employers reward workers anything minimal economic way braverman 's contribution sociology work


industry ie industrial sociology important theories labour process continue inform teaching research braverman 's thesis however contested andrew freidman work ''industry labour'' freidman suggests whilst direct control labour beneficial capitalist certain circumstances degree responsible autonomy granted unionized core workers order harness skill controlled conditions also richard edwards showed although hierarchy organizations remained constant additional forms control technical


applied social classes notion particular type technology workers exposed shapes experience forcefully argued classic study robert blauner argued work alienating types different technologies workers use alienation blauner four dimensions powerlessness meaninglessness isolation self estrangement individuals powerless ca n't control actions conditions work work meaningless gives employees little sense value interest worth work isolating workers cannot identify workplace


work self estranging subjective level worker sense involvement job blauner 's claims however fail recognize technology experienced variety ways studies shown cultural differences regard management union relations levels hierarchical control reward performance appraisal policies mean experience kind work vary considerably countries firms individualization work need workers flexible skills order respond technological changes means blauner 's characterization


work experience longer valid additionally workers today may work teams alleviate workers' sense alienation since involved entire process rather small part conclusion automative technologies computerized work systems typically enhanced workers' job satisfaction skill deployment better paid secure public private sector jobs non skilled manual work perpetuated job dissatisfaction especially many women involved type work see also bibliography sociology economic sociology industrial organizational psychology references


footnotes bibliography reading secondary sector economy economic sociology industrial relations


system avoid kleene rosser paradox afflicted original untyped lambda calculus church demonstrated could serve foundation mathematics referred higher order logic phrase type theory generally refers typed system based around lambda calculus one influential system per martin l f 's intuitionistic type theory proposed foundation constructive mathematics another thierry coquand 's calculus constructions used foundation coq lean proof assistants computerized proof writing programs type theories area active research

Formal science
Computer science
Logic in computer science
Type theory


type theory natural numbers often written math mathbb n math nat another boolean logic values simple terms types nat nat true bool terms built terms using function calls type theory function call called function application function application takes term given type results term another given type function application written ''function'' ''argument'' ''argument'' instead conventional ''function'' ''argument''''argument'' natural numbers


write math x math instead add math x math math math terms might rewritten nat nat nat terms may also contain variables variables always type assuming x variables type nat following also valid terms x nat x nat x x nat types nat bool already seen term add


nat function applied two nat computes nat type add covered later first need describe computes computation type theory built notation computation following terms different nat nat nat compute term nat type theory use words reduction reduce refer computation say nat reduces


nat written nat math twoheadrightarrow math nat computation mechanical accomplished rewriting term 's syntax terms contain variables reduced term x nat reduces x nat reduce sub term within term thanks church rosser theorem term without variables cannot reduced canonical term terms reduce nat canonical term canonical


terms natural numbers nat nat nat etc obviously terms compute term equal assuming x nat terms x nat x nat equal reduce x nat two terms equal substituted equality complex topic type theory many kinds equality kind equality two terms compute


lambda term function doubles argument x nat add x x nat math math nat variable name x variable type nat term add x x type nat assuming x nat thus lambda term type nat math math nat means given nat argument compute nat reduction aka computation defined lambda terms function applied aka called argument substituted parameter earlier saw


function application written putting parameter function term want call function parameter type nat write x nat add x x nat lambda term type nat math math nat meant given nat argument produce term type nat since given argument term type nat reduction works substituting argument parameter x term add x x


term computes add nat obviously computes nat lambda term often called anonymous function name often make things easier read name given lambda term merely notation mathematical meaning authors call notational equality name might given function using notation double nat math math nat x nat add x x function


different way write term double nat still computes nat dependent typing dependent typing type returned function depends value argument example type theory axiomatically defines type bool also axiomatically defines function function takes arguments true b c computes b false b c computes c type b c b c


type obvious b c type b c thus assuming bool nat false true bool b c different types type b c depends value use symbol pi indicate function takes argument returns type assuming types b c bool b b c c b


c pi bool b math math c math math b c type term either type second third argument depending value first argument type contain computation dependent typing amazingly powerful mathematicians say exists number math x math math x math prime exists number math x math property math p x math holds expressed dependent type property proven specific math x math visible


type result many details dependent typing long complicated introduction see article dependent typing lambda cube information universes pi terms return type type return value well must type contains types type contains types called universe often written symbol math u math sometimes hierarchy universes math u math math u math math u math math u math etc


universes complicated universe contains lead paradoxes like girard 's paradox details universes long complicated introduction common axiomatic types terms type theories usually functional core described set axiomatic types terms non exhaustive list common ones list ends inductive types powerful technique able construct ones list mathematical foundations used proof assistants coq lean based


calculus inductive constructions calculus constructions functional core inductive types empty type empty type terms type usually written math bot math math mathbb math used show something uncomputable type create function type math bot math know terms example type might exists number math x math math x math even math x math odd see product type


example constructed type terms say uninhabited unit type unit type exactly canonical term type written math top math math mathbb math single canonical term written unit type used show something exists computable type create function type math top math know one terms type least term say inhabited


boolean type boolean type exactly canonical terms type usually written bool math mathbb b math math mathbb math canonical terms usually true false boolean type defined function true b c math twoheadrightarrow math b false b c math twoheadrightarrow math c product type product type terms ordered pairs types b product type written math times math b canonical terms constructed function pair terms pair b


term type b term type b product type defined functions first second first pair b math twoheadrightarrow math second pair b math twoheadrightarrow math b besides ordered pairs type used logical holds b also used intersection holds one types type theory dependent typing dependent pairs dependent pair second type depends value first term


thus type written math sigma math b b type math math u useful showing existence property b sum type sum type tagged union types b type b holds either term type term type b knows one holds type comes constructors injectionleft injectionright call injectionleft takes returns canonical term type


type function define also takes term pz p value zero function ps p n math math p n says transform value n value n thus computation rules r p pz ps math twoheadrightarrow math pz r p pz ps math n math math twoheadrightarrow math ps r p pz ps math n math function add used earlier defined using r add nat math math nat math math nat r nat math math nat n nat n


n nat g nat math math nat nat g identity type identity type third concept equality type theory first notational equality definitions like nat mathematical meaning useful readers second judgemental equality two terms compute term like x x compute x type theory needs another form equality


requires two terms b type written b x x type would x x canonical terms created constructor reflexivity call reflexivity takes term returns canonical term type computation identity type done function j function j lets term dependent b term type b rewritten b replaced


j one directional able substitute b proven identity type reflexive symmetric transitive canonical terms always x compute term x create term x x use r function see natural numbers r function 's argument p defined x nat x x arguments act like parts induction proof pz p


becomes base case ps p n math math p n becomes inductive case essentially says x x x replaced canonical value expression reflexivity x application function r type x nat math math x x use function j substituted x x term way identity type able capture equalities possible judgemental equality


clear possible create type way create terms type without term type possible use function j substitute another term complexities equality type theory make active research area see homotopy type theory inductive types inductive types way axiomatically create large variety types fact types described defined using inductive


types type 's canonical values constructor functions specified computation determined structural recursion similar powerful ways create types include induction recursion induction induction also way create similar types using lambda terms called scott encoding note type theories usually include coinductive types represent infinite data type type theories limit functions proven halt differences set theory traditional foundation mathematics set theory paired logic


common one cited zermelo fraenkel set theory known zf axiom choice zfc type theories differ foundation number ways set theory built top logic requires separate system like predicate logic underneath type theory concepts like encoded types type theory set theory logic law excluded middle every theorem true false type theory defines concepts types leads


intuitionistic logic law excluded middle however law proven types set theory element restricted one set element appear subsets unions sets type theory terms generally belong one type subset would used type theory use predicate function use dependently typed product type element math x math paired proof subset 's property holds math x math union would used type


theory uses sum type contains new canonical terms type theory built notion computation thus different terms type theory compute value moreover functions defined computationally lambda terms set theory means another way refer value type theory 's computation require complicated concept equality set theory usually encodes numbers sets empty set set containing empty set etc see set theoretic definition


natural numbers type theory encode numbers functions using church encoding naturally inductive types canonical term constructor created inductive type closely resembling peano 's axioms set theory set builder notation create set defined allows create uncountable sets type theories syntactic limits countably infinite terms additionally type theories require computation always halt limit recursively generable terms result type theories use real


numbers computable numbers set theory axiom choice axiom controversial particularly applied uncountable sets type theory equivalent statement theorem type provable inhabited term type theory proofs mathematical objects type x x cannot used unless term type term represents proof x x thus type theory opens proofs studied mathematical objects proponents type theory also point connection


constructive mathematics bhk interpretation connected logic curry howard isomorphism connections category theory technical details type theory formal mathematical logic logics judgements meaning term math x math true term math x math well formed formula type theory additional judgements define types relate terms types terms term logic recursively defined constant symbol variable function application term applied another term constant symbols


natural numbers true booleans axiomatic functions like thus terms x true judgements type theories judgements math math type math math term type math math type math math equal type math math terms math math math math type math math equal judgements made assumption thus might say assuming math x math term type bool math math term type nat


x term type nat mathematical notation assumptions comma separate list ''term'' ''type'' precede turnstile symbol ' math vdash math ' thus example statement formally written x bool nat math vdash math x nat assumptions nothing left turnstile math vdash math nat math math nat list assumptions called context common see symbol ' math gamma math ' used represent assumptions thus formal notation


different judgements usually class wikitable formal notation judgements description math gamma vdash math type math math type assumptions math gamma math math gamma vdash math math math term type math math assumptions math gamma math math gamma vdash math type math math equal type math math assumptions math gamma math math gamma vdash math terms math math math math type math math equal assumptions math gamma math note judgement equality terms


lambda term go line case one judgement required term b type b assuming term type assumptions math gamma math resulting judgement states new lambda term type math math b assumptions math gamma math line rules syntactic work rewriting generate particular judgement type theory must rule generate must rules generate


rule 's required inputs rules inputs rules applied rules form proof tree usually drawn gentzen style target judgement root bottom rules require inputs leaves top see http natural deduction proofs type theory natural deduction proofs type theory example rule require inputs one states term type nat math display block begin array c hline vdash nat end array math type theory usually number rules including


ones rearrange assumptions add assumption weakening define reflexivity symmetry transitivity judgemental equality define substitution application lambda terms judgemental equality etc axiomatic type usually comes different sets rules type formation rules say create type term introduction rules define canonical terms constructor functions like pair term elimination rules define functions like first second r computation rules specify computation performed type specific functions properties type theories terms usually belong single type however


''type inhabitation'' abbreviated math exists e gamma vdash e tau math given type environment math gamma math type math tau math decide whether exists term math e math assigned type math tau math type environment math gamma math girard 's paradox shows type inhabitation strongly related consistency type system curry howard correspondence sound system must uninhabited types opposition terms types also views one ''implementation'' ' 'specification'' program synthesis computational counterpart type inhabitation see used


construct parts programs specification given form type information research areas homotopy type theory differs intuitionistic type theory mostly handling equality type recently proposed cubical type theory homotopy type theory normalization interpretations type theory type theory connections areas mathematics proponents type theory foundation often mention connections justification use types propositions terms proofs used foundation certain types interpreted propositions statements


rules resemble programs programming languages thus correspondence often summarized proofs programs logic operators exists led per martin l f invented dependent type theory intuitionistic logic types interpreted propositions set common types used connect make logic types however logic classical logic intuitionistic logic law excluded middle double negation natural relation types logical


propositions type representing proposition able create function math top math indicates proof able create function math bot math indicates proof inhabitable types proven uninhabitable types disproven ''warning interpretation lead lot confusion type theory may ''terms'' true false type bool act like boolean logic time ''types'' math top math math bot math represent true provable


math lor b math math b math sum type math forall p math pi p dependent function exists math exists p math sigma p dependent product type interpretation law excluded middle term type pi math bot math likewise double negation term type pi


two terms judgementally equal constructive mathematics per martin l f proposed intuitionistic type theory foundation constructive mathematics constructive mathematics requires proving exists math x math property p math x math must particular math x math proof property p type theory existence accomplished using dependent product type proof requires term type term math math first math math produce math x math second math math produce proof p math x math example non constructive proof


proof contradiction first step assuming math x math exist refuting contradiction conclusion step case math x math exist last step double negation concluding math x math exists clear constructive mathematics still allows refute contradiction prove case math x math exist constructive mathematics allow last step removing double negation conclude math x math exists constructive mathematics often


used intutionistic logic evidenced brouwer heyting kolmogorov interpretation type theories proposed foundations constructive includes ones used proof assistants possible add non constructive features type theory rule assumption include operators continuations call current continuation however operators tend break desirable properties canonicity parametricity category theory although initial motivation category theory far removed foundationalism two fields turned deep connections john lane bell writes fact


exponentials one non terminal object correspond untyped calculus observed independently lambek dana scott around locally cartesian closed categories correspond martin l f type theories seely interplay known categorical logic subject active research since see monograph jacobs instance homotopy type theory attempts combine type theory category theory focuses equalities especially equalities types list type theories major simply typed lambda calculus higher order logic intuitionistic type theory system f lf often used define type


theories calculus constructions derivatives minor automath st type theory utt luo 's unified theory dependent types forms combinatory logic others defined lambda cube also known pure type systems others name typed lambda calculus active research homotopy type theory explores equality types cubical type theory implementation homotopy type theory applications mathematical foundations first computer proof assistant called automath used type theory encode mathematics computer martin l f specifically developed intuitionistic type theory encode ''all'' mathematics serve new foundation mathematics


ongoing research mathematical foundations using homotopy type theory mathematicians working category theory already difficulty working widely accepted foundation zermelo fraenkel set theory led proposals lawvere 's elementary theory category sets etcs homotopy type theory continues line using type theory researchers exploring connections dependent types especially identity type algebraic topology specifically homotopy proof assistants much current research type theory driven proof checkers interactive proof assistants automated theorem provers systems use type theory


mathematical foundation encoding proofs surprising given close connection type theory programming languages lf used twelf often define type theories many type theories fall higher order logic used hol family provers pvs computational type theory used nuprl calculus constructions derivatives used coq matita lean utt luo 's unified theory dependent types used agda programming language proof assistant many type theories supported lego isabelle isabelle also


supports foundations besides type theories zfc mizar example proof system supports set theory programming languages extensive overlap interaction fields type theory type systems type systems programming language feature designed identify bugs static program analysis type checking algorithms semantic analysis phase compiler connection type theory prime example agda programming language uses utt luo 's unified theory dependent types type system programming language ml developed


manipulating type theories see lcf type system heavily influenced linguistics type theory also widely used formal theories semantics natural languages especially montague grammar descendants particular categorial grammars pregroup grammars extensively use type constructors define types ''noun'' ' 'verb'' etc words common construction takes basic types math e math math math individuals truth values respectively defines set types recursively follows math math math b math types math langle ab rangle math nothing except basic types


constructed means previous clause types complex type math langle ab rangle math type functions entities type math math entities type math b math thus one types like math langle et rangle math interpreted elements set functions entities truth values ie indicator functions sets entities expression type math langle langle et ranglet rangle math function sets entities truth values ie indicator function set sets latter type standardly taken type natural language quantifiers like ''


everybody'' '' nobody'' montague barwise cooper social sciences gregory bateson introduced theory logical types social sciences notions double bind logical levels based russell 's theory types see also type system programming language feature find avoid bugs foundations mathematics external links introductory material https ncatlaborg nlab show type theory type theory nlab articles many topics https platostanfordedu entries type theory intuitionistic intuitionistic type theory article stanford encyclopedia philosophy https hometticedu dreyer course papers barendregtpdf lambda calculus types book henk barendregt https archive pmlgithubio martin lof pdfs bibliopolis book retypeset pdf intuitionistic type theory notes per martin l f https wwwcsechalmersse research group logic book bookpdf programming


martin l f type theory book https homotopytypetheoryorg book homotopy type theory book proposed homotopy type theory mathematical foundation advanced material http listsseasupennedu mailman listinfo types list types forum mdash moderated e mail forum focusing type theory computer science operating since ftp ftpcscornelledu pub nuprl doc bookpsgz nuprl book http wwwnuprlorg book introduction type theoryhtml introduction type theory http wwwcschalmersse cs research logic types tutorialshtml types project lecture notes summer schools http wwwcschalmersse cs research logic typesss programhtml summer school introductory lectures https wwwcsuoregonedu research summerschool archiveshtml oregon programming languages summer school many lectures notes https wwwcsuoregonedu research summerschool summer curriculumhtml summer lectures including https wwwyoutubecom watchv snefrwbidc list plgcr p yncjxrzdgq sjkv f j hufeqn robert harper 's talks youtube https wwwcsuoregonedu research summerschool summer curriculumhtml summer types logic semantics verification reading covers type


sun mhd system well understood '''magnetohydrodynamics''' '''mhd''' '''also magneto fluid dynamics''' '''hydro shy magnetics''' study magnetic properties behaviour electrically conducting fluids examples magneto shy fluids include plasmas liquid metals salt water electrolytes word magneto shy hydro shy dynamics derived ''magneto '' meaning magnetic field ''hydro '' meaning water ' 'dynamics'' meaning movement field mhd initiated hannes alfv n received nobel prize physics fundamental concept behind mhd magnetic fields induce currents moving conductive fluid

Natural science
Space science
Numerical simulations
Magnetohydrodynamics


turn polarizes fluid reciprocally changes magnetic field set equations describe mhd combination navier stokes equations fluid dynamics maxwell equations electro shy magnetism differential equations must solved simultaneously either analytically numerically history michael faraday first recorded use word ''magnetohydrodynamics'' hannes alfv n ref ebbing salty water flowing past london 's waterloo bridge interacts earth 's magnetic field produce potential difference two river banks michael faraday called effect magneto electric induction tried experiment


ideal mhd lenz 's law dictates fluid sense ''tied'' magnetic field lines explain ideal mhd small rope like volume fluid surrounding field line continue lie along magnetic field line even twisted distorted fluid flows system sometimes referred magnetic field lines frozen fluid connection magnetic field lines fluid ideal mhd fixes topology magnetic field fluid example set magnetic field lines


tied knot remain long fluid plasma negligible resistivity difficulty reconnecting magnetic field lines makes possible store energy moving fluid source magnetic field energy become available conditions ideal mhd break allowing magnetic reconnection releases stored energy magnetic field ideal mhd equations magnetohydrodynamic flow simulation showing magnetic flux density ideal mhd equations consist continuity equation cauchy momentum equation ampere 's law neglecting displacement current


temperature evolution equation fluid description kinetic system closure approximation must applied highest moment particle distribution equation often accomplished approximations heat flux condition adiabaticity isothermality main quantities characterize electrically conducting fluid bulk plasma velocity field current density mass density plasma pressure flowing electric charge plasma source magnetic field electric field quantities generally vary


time vector operator notation used particular gradient divergence curl mass continuity equation math frac partial rho partial nabla cdot left rho mathbf v right math cauchy momentum equation math rho left frac partial partial mathbf v cdot nabla right mathbf v mathbf j times mathbf b nabla p math lorentz force term expanded using amp 's law vector calculus identity math tfrac nabla mathbf b cdot mathbf b mathbf b cdot nabla mathbf b mathbf b times nabla times mathbf b math give math mathbf j times mathbf b frac left mathbf b cdot nabla right mathbf b mu nabla left frac b mu right math first term right hand side magnetic tension force second term magnetic pressure force