asia even earlier work james fenimore cooper 's classic novel ''the spy'' written american spy new york revolutionary war many th century spy scandals much information became publicly known national spy agencies dozens real life secret agents sensational stories piqued public interest profession largely limits human interest news reporting natural consequence secrecy inherent work fill blanks popular conception secret agent formed largely th st century fiction film attractive sociable


real life agents valerie plame find little employment serious fiction however fictional secret agent often loner sometimes amoral existential hero operating outside everyday constraints society loner spy personalities may stereotype convenience authors already knew write loner private investigator characters sold well present johnny fedora achieved popularity fictional agent early cold war espionage james bond commercially successful many spy characters created intelligence insiders struggle

Applied science
Military sciences
Espionage


less fantastic rivals include le carr 's george smiley harry palmer played michael caine jumping spy bandwagon writers also started writing spy fiction featuring female spies protagonists ''the baroness'' graphic action sex compared novels featuring male protagonists spy fiction also permeated video game world games ''perfect dark'' ''goldeneye '' ''no one lives forever '' '' '' ''metal gear'' series espionage also made way comedy depictions tv series ''get smart''


finnish film ''agent deadly curves'' ''johnny english'' film trilogy portrays inept spy movie ''spies like us'' depicts pair none bright men sent soviet union investigate missile historical novel ''the emperor spy'' highlights adventurous life us colonel sidney forrester mashbir attempted prevent war japan war erupt became general macarthur 's top advisor pacific theater world war two black widow also fictional agent introduced


russian spy antagonist superhero iron man later became agent fictional spy agency shield member superhero team avengers see also american espionage china animals used espionage chinese intelligence operations united states clandestine operation classified information dumpster diving intelligence assessment flying monkeys psychology history soviet espionage human intelligence intelligence gathering labor spies list cryptographers list intelligence agencies list intelligence gathering disciplines military intelligence ninja operation snow white security clearance spymaster spy museum disambiguation jalal haji zawar references


citations ref ref name fashans ref ref name jyaames ref works cited reading aldrich richard j christopher andrew eds ''secret intelligence reader'' nd ed focus st century reprints essays scholars https wwwamazoncom dp excerpt andrew christopher ''the secret world history intelligence'' burnham frederick russell ''taking chances'' felix christopher pseudonym james mccarger ''a short course secret war th edition'' madison books november friedman george ''america 's secret war inside hidden worldwide struggle united states enemies'' gopnik


adam spy vs spy vs spy valuable espionage ''the new yorker'' september pp nbsp seems paranoid paradox espionage better intelligence dumber conduct know less anticipate hard information ignored wildly misinterpreted happens seeming national advance intelligence squandered cross bred confusion political rivalry mutual bureaucratic suspicions intergovernmental competition fear press well leaks press seasoned dashes sexual jealousy adulterous intrigue p nbsp jeffreys jones rhodri ''in spies


trust story western intelligence'' covers us britain jenkins peter ''surveillance tradecraft professional 's guide surveillance training'' kahn david ''the codebreakers comprehensive history secret communication ancient times internet'' revised edition first published keegan john ''intelligence war knowledge enemy napoleon al qaeda'' knightley phillip ''the second oldest profession spies spying twentieth century'' norton lerner brenda wilmoth k lee lerner eds ''terrorism essential primary sources'' thomas gale lerner k lee brenda wilmoth lerner eds ''encyclopedia


espionage intelligence security'' worldwide recent coverage pages may ernest r ed ''knowing one 's enemies intelligence assessment two world wars'' o'toole george ''honorable treachery history us intelligence espionage covert action american revolution cia'' murray williamson allan reed millett eds ''calculations net assessment coming world war ii'' owen david ''hidden secrets complete history espionage technology used support it'' richelson jeffery ''a century spies intelligence twentieth century'' richelson


animated gif photographic sequence shot eadweard muybridge chronophotographic works regarded movies recorded proper way replay material motion '''film''' also called '''movie''' '''motion picture''' '''moving picture''' work visual art used simulate experiences communicate ideas stories perceptions feelings beauty atmosphere use moving images images generally accompanied sound rarely sensory stimulations word '''cinema''' short cinematography often used refer filmmaking film


industry art form result moving images film created photographing actual scenes motion picture camera photographing drawings miniature models using traditional animation techniques means cgi computer animation combination techniques visual effects introduction digital production film physical strip film consisting series static still images live action photographed rate frames images per second images


entire process production distribution exhibition films recorded photochemical form traditionally included analogous optical soundtrack graphic recording spoken words music sounds accompany images runs along portion film exclusively reserved projected films cultural artifacts created specific cultures reflect cultures turn affect film considered important art form source popular entertainment powerful medium educating indoctrinating citizens visual basis film gives universal power


communication films become popular worldwide attractions use dubbing subtitles translate dialog languages individual images make film called frames projection traditional celluloid films rotating shutter causes intervals darkness frame turn moved position projected viewer notice interruptions effect known persistence vision whereby eye retains visual image fraction second source disappears perception motion partly


due psychological effect called phi phenomenon name film originates fact photographic film also called film stock historically medium recording displaying motion pictures many terms exist individual motion picture including ''picture'' ''picture show'' ''moving picture'' ''photoplay'' ''flick'' common term united states ''movie'' europe ''film'' preferred common terms field general include ''the big screen'' ''the silver screen'' ''the movies'' ''cinema'' last commonly used overarching term scholarly texts


critical essays early years word ' 'sheet'' sometimes used instead ' 'screen'' 'film' general good term refer long standard commercial video production since ambiguous general therefore requires context correct interpretation history frame ''roundhay garden scene'' world 's earliest surviving film produced using motion picture camera louis le prince berlin wintergarten theatre site first cinema ever short film presented skladanowsky brothers november pictured variety show


half th century could feature mechanical slides rear projection mobile projectors superimposition dissolving views live actors smoke sometimes project images upon odors sounds even electric shocks celluloid stroboscopic animation principle introduced ph nakisticope also applied zoetrope since flip book since praxinoscope since became basic principle cinematography experiments early phenakisticope based animation projectors made least early jules duboscq marketed ph nakisticope projection systems france photography introduced


ph nakisticope stereoscope suggested stereoscope inventor charles wheatstone use photographs plaster sculptures different positions animated combined device jules duboscq patented instrument st r oscope fantascope ou b oscope marginally advertised short period commercial failure complete instrument yet located one bioscope disc preserved plateau collection ghent university stereoscopic photographs machine late first examples instantaneous photography came provided hope


motion photography would soon possible took decades successfully combined method record series sequential images real time eadweard muybridge eventually managed take series photographs running horse battery cameras line along track published results ''the horse motion'' cabinet cards muybridge well tienne jules marey ottomar ansch tz many others would create many chronophotography studies muybridge contours dozens chronophotographic series traced onto glass discs


projected zoopraxiscope lectures ansch tz developed electrotachyscope project diapositive photographic images glass disks moving images looped long deemed interesting audience mile reynaud already mentioned possibility projecting images patent application praxinoscope presented praxinoscope projection device soci fran aise de photographie june market ''praxinoscope projection'' developed device th tre optique could project longer sequences


separate backgrounds patented created several movies machine painting images hundreds gelatin plates mounted cardboard frames attached cloth band october march reynaud gave shows total visitors mus e gr vin paris famous shot georges li ''le voyage dans la lune trip moon '' early narrative film also early science fiction film first motion pictures end introduction lengths celluloid


photographic film invention motion picture cameras could photograph indefinitely long rapid sequence images using one lens allowed several minutes action captured stored single compact reel film early films made viewed one person time peep show device kinetoscope mutoscope others intended projector mechanically similar camera sometimes actually machine used shine intense light processed printed film


eidoloscope company arguably better known french brothers auguste louis lumi ten productions private screenings preceded several months latham 's slightly predating lumi brothers' early evolution earliest films simply one static shot showed event action editing cinematic techniques typical films showed employees leaving factory gate people walking street view front trolly traveled city main street according legend film showed locomotive


high speed approaching audience audience panicked ran theater around turn th century films started stringing several scenes together tell story filmmakers first put several shots scenes discovered one shot follows another act establishes relationship content separate shots minds viewer relationship makes film storytelling possible simple example person shown looking window whatever next shot shows regarded view person


seeing scene single stationary shot action occurring scenes later broken multiple shots photographed different distances angles techniques camera movement developed effective ways tell story film sound film became commercially practical late motion pictures purely visual art innovative silent films gained hold public imagination rather leave audiences noise projector accompaniment theater owners hired pianist organist


large urban theaters full orchestra play music fit mood film given moment early films came prepared list sheet music used purpose complete film scores composed major productions clip charlie chaplin silent film ''the bond'' rise european cinema interrupted outbreak world war film industry united states flourished rise hollywood typified prominently innovative work w griffith


''the birth nation'' ''intolerance'' however european filmmakers eisenstein f w murnau fritz lang many ways inspired meteoric wartime progress film griffith along contributions charles chaplin buster keaton others quickly caught american film making continued advance medium sound development electronic sound recording technologies made practical incorporate soundtrack speech music sound effects synchronized action screen resulting sound films initially distinguished


usual silent moving pictures movies calling talking pictures talkies revolution wrought swift silent film practically extinct us already referred old medium color another major technological development introduction natural color meant color photographically recorded nature rather added black white prints hand coloring stencil coloring arbitrary procedures although earliest processes typically yielded colors far natural appearance advent sound films quickly made silent films theater musicians obsolete


color replaced black white much gradually pivotal innovation introduction three strip version technicolor process first used animated cartoons also live action short films isolated sequences feature films entire feature film ''becky sharp'' expense process daunting favorable public response form increased box office receipts usually justified added cost number films made color slowly increased year year growing influence television early proliferation


prices gradually came color broadcasts became common sales boomed overwhelming public verdict favor color clear final flurry black white films released mid decade hollywood studio productions filmed color usual exceptions made insistence star filmmakers peter bogdanovich martin scorsese later decades following decline studio system saw changes production style film various new wave movements including french new wave indian new wave japanese new wave


new hollywood rise film school educated independent filmmakers contributed changes medium experienced latter half th century digital technology driving force change throughout digital projection largely replaced earlier problem prone film systems become popular early film theory mm spring wound bolex h reflex camera popular entry level camera used film schools film theory seeks develop concise systematic concepts apply study film art concept film


theory feminist film theory others hand critics analytical philosophy tradition influenced wittgenstein try clarify misconceptions used theoretical studies produce analysis film 's vocabulary link form life language film considered language james monaco wrote classic text film theory titled ''read'' film addresses director ingmar bergman famously said andrei tarkovsky greatest director one invented ''new language'' true nature film captures life


reflection life dream example language sequence back forth images one speaking actor 's left profile followed another speaking actor 's right profile repetition language understood audience indicate conversation describes another theory film degree rule visual story telling device ability place viewer context psychologically present use visual composition editing hollywood style includes narrative theory due overwhelming practice rule


movie studios based hollywood california film 's classical era another example cinematic language shot zooms forehead actor expression silent reflection cuts shot younger actor vaguely resembles first actor indicating first person remembering past self edit compositions causes time transition montage montage technique separate pieces film selected edited pieced together make new section film scene could show man


going battle flashbacks youth home life added special effects placed film filming complete filmed separately perhaps different actors final version called montage directors developed theory montage beginning eisenstein complex juxtaposition images film ''battleship potemkin'' ref name jnfilmtheory ref incorporation musical visual counterpoint scene development mise en scene editing effects led complex techniques comparable used opera ballet film criticism ref width align right style padding px border px film criticism


critic 's overall judgment film plot summary description film assessment director 's screenwriters' work makes majority film reviews still important impact whether people decide see film prestige films dramas art films influence reviews important poor reviews leading critics major papers magazines often reduce audience interest attendance impact reviewer given film 's box office performance matter debate observers claim


movie marketing intense well coordinated well financed reviewers cannot prevent poorly written filmed blockbuster attaining market success however cataclysmic failure heavily promoted films harshly reviewed well unexpected success critically praised independent films indicates extreme critical reactions considerable influence observers note positive film reviews shown spark interest little known films conversely several films film companies little confidence refuse give reviewers advanced viewing avoid


widespread panning film however usually backfires reviewers wise tactic warn public film may worth seeing films often poorly result journalist film critics sometimes called film reviewers critics take academic approach films publishing film journals writing books films using film theory film studies approaches study film filming techniques work effect people rather reviews published newspapers appearing television articles


published scholarly journals market magazines also tend affiliated colleges universities professors instructors industry founded babelsberg studio near berlin first large scale film studio world forerunner hollywood still produces global blockbusters every year making showing motion pictures became source profit almost soon process invented upon seeing successful new invention product native france lumi res quickly set touring continent exhibit first films privately


royalty publicly masses country would normally add new local scenes catalogue quickly enough found local entrepreneurs various countries europe buy equipment photograph export import screen additional product commercially oberammergau passion play first commercial motion picture ever produced pictures soon followed motion pictures became separate industry overshadowed vaudeville world dedicated theaters companies formed specifically produce distribute films motion picture actors became major celebrities commanded huge fees performances


charlie chaplin contract called annual salary one million dollars film also image storage playback system television programming introduction videotape recorders united states much film industry centered around hollywood california regional centers exist many parts world mumbai centered bollywood indian film industry 's hindi cinema produces largest number films world though expense involved making films led cinema production concentrate auspices


movie studios recent advances affordable film making equipment allowed independent film productions flourish profit key force industry due costly risky nature filmmaking many films large cost overruns example kevin costner 's ''waterworld'' yet many filmmakers strive create works lasting social significance academy awards also known oscars prominent film awards united states providing recognition year films based artistic merits also large industry educational instructional films made lieu


divisions film propaganda authoritarian governments psychological subliminal effects eg flashing soda screening fields may create derivative fields movie review section newspaper television guide sub industries spin film popcorn makers film related toys eg ''star wars'' figures sub industries pre existing industries may deal specifically film product placement advertising within films terminology terminology used describing motion pictures varies considerably british american english british usage name medium


film word movie understood seldom used ref name britam ref ref name sdope ref additionally pictures plural used semi frequently refer place movies exhibited american english may called movies becoming outdated countries place movies exhibited may called cinema movie theatre contrast united states movie predominant form although words film movie sometimes used interchangeably film often used considering artistic theoretical technical aspects term movies often refers entertainment


reproduce photochemical film reproduction based called transfer advent theatrical film industry television industry began using videotape recording medium many decades tape solely analog medium onto moving images could either recorded transferred film filming refer photochemical medium chemically records visual image act recording respectively however act shooting images visual media digital camera still called filming resulting works often called films interchangeable


movies despite shot film silent films need utterly silent films movies without audible dialogue including musical accompaniment word talkies refers earliest sound films created audible dialogue recorded playback along film regardless musical accompaniment cinema either broadly encompasses films movies roughly synonymous film theatrical exhibition capitalized referring category art silver screen refers projection screen used exhibit films


extension also used metonym entire film industry widescreen refers larger width height frame compared earlier historic aspect ratios ref name imdbmovietermsw ref feature length film feature film conventional full length usually minutes commercially stand without films ticketed screening ref name imdbmovietermsf ref short film long feature length film often screened shorts preceding feature length film independent film made outside conventional film industry us usage one


talks screening projection movie video screen public private theater british english film showing happens cinema never theatre different medium place altogether ref name sdope cinema usually refers arena designed specifically exhibit films screen affixed wall theater usually refers place live non recorded action combination thereof occurs podium type stage including amphitheater theaters still screen movies though theater


may due loss deterioration film master prints movie originally existed due advent digital film production distribution physical film might absent entirely double feature screening two independently marketed stand alone feature films viewing watching film sales box office refer tickets sold theater currently rights sold individual showings release distribution often simultaneous screening film preview screening advance main


release film may also sequel portrays events following film ''bride frankenstein'' early example films one characters story arcs subject themes movies become series james bond series existing outside specific story timeline usually exclude film part series film portrays events occurring earlier timeline another film released film sometimes called prequel example ''butch


sundance early days'' credits end credits list gives credit people involved production film films usually start film credits often ending title card saying end equivalent often equivalent depends language production onward film 's credits usually appear end films however films credits end film often repeat credits near start film therefore appear twice


film 's acting leads less frequently appearing near beginning appear end often happens director 's credit credits appearing near beginning film usually called titles beginning titles post credits scene scene shown end credits ''ferris bueller 's day off'' post credit scene ferris tells audience film go home film 's cast refers collection actors actresses appear star


film star actor actress often popular one many cases celebrity plays central character film occasionally word also used refer fame members crew director personality martin scorsese crew usually interpreted people involved film 's physical construction outside cast participation could include directors film editors photographers grips gaffers set decorators prop masters costume designers person part film 's cast


crew woody allen directed starred ''take money run'' film goer movie goer film buff person likes often attends films movies though often latter could also see oneself student films movies filmic process intense interest films film theory film criticism known cinephilia film enthusiast known cinephile cineaste preview preview performance refers showing film select audience usually


purposes corporate promotions public film premiere previews sometimes used judge audience reaction unexpectedly negative may result recutting even refilming certain sections based audience response one example film changed negative response test screening 's ''first blood'' test audience responded negatively death protagonist john rambo vietnam veteran end film company wrote shot new ending character survives trailer teaser trailers previews advertisements


films shown months cinema back early days cinema theaters one two screens certain trailers shown films going shown later theaters added screens new theaters built lot screens different trailers shown even n't going play film theater film studios realized trailers shown even n't going shown particular theater


patrons would go different theater see film came term trailer comes originally shown end film program practice last long patrons tended leave theater films ended name stuck trailers shown film film double feature program begins film trailers also common dvds blu ray discs well internet mobile devices trailers created engaging interesting


viewers result internet era viewers often seek trailers watch ten billion videos watched online annually film trailers ranked third news user created videos teasers much shorter preview advertisement lasts seconds teasers used get patrons excited film coming next six twelve months teasers may produced even film production completed education propaganda film used range goals including education propaganda purpose


primarily educational film called educational film examples recordings academic lectures experiments film based classic novel film may propaganda whole part films made leni riefenstahl nazi germany us war film trailers world war ii artistic films made stalin sergei eisenstein may also works political protest films andrzej wajda subtly films andrei tarkovsky film may considered educational propaganda others


revision distribution involved production significant steps becomes typical production cycle hollywood style film main stages defined development pre production production post production distribution production cycle usually takes three years first year taken ' 'development'' second year comprises ''preproduction'' ''production'' third year ''post production'' ' 'distribution'' bigger production resources takes important financing becomes feature films artistic works creators' perspective eg film director cinematographer screenwriter profit business entities


production companies crew film crew group people hired film company employed production photography phase purpose producing film motion picture ''crew'' distinguished ''cast'' actors appear front camera provide voices characters film ''crew'' interacts also distinct ''production staff'' consisting producers managers company representatives assistants whose primary responsibility falls pre production post production phases screenwriters film editors communication ''production'' ''crew''


generally passes director staff assistants medium large crews generally divided departments well defined hierarchies standards interaction cooperation departments acting crew handles everything photography phase props costumes shooting sound electrics ie lights sets production special effects caterers known film industry craft services usually considered part crew technology film stock consists transparent celluloid acetate polyester base coated emulsion containing light sensitive chemicals cellulose nitrate first type film base used record


motion pictures due flammability eventually replaced safer materials stock widths film format images reel rich history though large commercial films still shot distributed theaters nbsp mm prints originally moving picture film shot projected various speeds using hand cranked cameras projectors though frames per minute frame generally cited standard silent speed research indicates films shot frame frame projected frame often reels included instructions


terms preservation storage motion picture industry exploring many alternatives films cellulose nitrate base copied onto modern safety films studios save color films use separation masters three b w negatives exposed red green blue filters essentially reverse technicolor process digital methods also used restore films although continued obsolescence cycle makes poor choice long term preservation film preservation decaying film stock matter concern film historians archivists


companies interested preserving existing products order make available future generations thereby increase revenue preservation generally higher concern nitrate single strip color films due high decay rates black white films safety bases color films preserved technicolor imbibition prints tend keep much better assuming proper handling storage films recent decades recorded using analog video technology similar used television production modern digital video cameras digital projectors gaining ground well approaches preferred


film makers especially footage shot digital cinema evaluated edited non linear editing systems nle without waiting film stock processed migration gradual major motion pictures still shot film independent lumi brothers among first filmmakers independent filmmaking often takes place outside hollywood major studio systems independent film indie film film initially produced without financing distribution major film studio creative business technological reasons contributed growth indie


film scene late th early st century business side costs big budget studio films also lead conservative choices cast crew trend hollywood towards co financing two thirds films put warner bros joint ventures ref name variety ref hopeful director almost never given opportunity get job big budget studio film unless significant industry experience film television also studios rarely produce films unknown actors particularly lead


roles advent digital alternatives cost professional film equipment stock also hurdle able produce direct star traditional studio film advent consumer camcorders importantly arrival high resolution digital video early lowered technology barrier film production significantly production post production costs significantly lowered hardware software post production installed commodity based personal computer technologies dvds firewire connections wide variety professional


consumer grade video editing software make film making relatively affordable since introduction digital video dv technology means production become democratized filmmakers conceivably shoot film digital video camera edit film create edit sound music mix final cut high end home computer however means production may democratized financing distribution marketing remain difficult accomplish outside traditional system independent filmmakers rely film festivals get films noticed sold distribution arrival internet based video websites


youtube veoh changed filmmaking landscape enabling indie filmmakers make films available public open content film open content film much like independent film produced open collaborations source material available license permissive enough allow parties create fan fiction derivative works traditional copyright like independent filmmaking open source filmmaking takes place outside hollywood major studio systemsfor example film balloon based real event cold war fan film


fan film film video inspired film television program comic book similar source created fans rather source 's copyright holders creators fan filmmakers traditionally amateurs notable films actually produced professional filmmakers film school class projects demonstration reels fan films vary tremendously length short faux teaser trailers non existent motion pictures rarer full length motion pictures distribution film distribution process film made available viewing audience


normally task professional film distributor would determine marketing strategy film media film exhibited made available viewing may set release date matters film may exhibited directly public either movie theater historically main way films distributed television personal home viewing including dvd video blu ray disc video demand online downloading television programs broadcast syndication etc ways distributing film include rental personal purchase film variety


media formats vhs tape dvd internet downloading streaming using computer animation animated image horse made using eight pictures animation technique frame film produced individually whether generated computer graphic photographing drawn image repeatedly making small changes model unit see claymation stop motion photographing result special animation camera frames strung together resulting film viewed speed frames


per second illusion continuous movement due phi phenomenon generating film labor intensive tedious though development computer animation greatly sped process animation time consuming often expensive produce majority animation tv films comes professional animation studios however field independent animation existed least since animation produced independent studios sometimes single person several independent animation producers gone enter professional animation industry limited animation


way increasing production decreasing costs animation using short cuts animation process method pioneered upa popularized hanna barbera united states osamu tezuka japan adapted studios cartoons moved movie theaters television although animation studios using digital technologies productions specific style animation depends film camera less animation made famous film makers like norman mclaren len lye stan brakhage painted drawn directly onto pieces film


run projector see also docufiction hybrid genre filmophile lost film ''the movies'' simulation game film industry taking place dawn cinema lists bibliography film genre glossary motion picture terms index video related articles list film awards list film festivals list film periodicals list years film lists films list books films outline film platforms television film web film notes references reading burton gideon randy astle jt eds mormons film entire special issue ''byu


studies'' brigham young university vol p ill hickenlooper george ''reel sic conversations candid interviews film 's foremost directors critics'' series ''citadel press book '' new york carol publishing group xii p external links https wwwallmoviecom allmovie nbsp information films actors directors biographies reviews cast production credits box office sales movie data http wwwfilmsiteorg film site nbsp reviews classic films https wwwrottentomatoescom rottentomatoescom nbsp movie reviews previews forums photos cast info https webarchiveorg web http imdbcom internet movie database imdb nbsp information current historical films cast listings visual arts media media formats french


inventions articles containing video clips


'''film criticism''' analysis evaluation films film medium general film criticism divided two categories journalistic criticism appears regularly newspapers magazines popular mass media outlets academic criticism film scholars informed film theory published academic journals academic film criticism rarely takes form review instead likely analyse film place within history genre whole film history history film introduced late th century

Humanities
Performing arts
Film
Film criticism


earliest artistic criticism film emerged early first paper serve critique film came ''the optical lantern cinematograph journal'' followed ''bioscope'' ref name ref film relatively new form art comparison music literature painting existed since ancient times early writing film sought argue films could also considered form art ricciotto canudo wrote manifesto proclaiming cinema sixth art later seventh art many decades film still


treated less prestige longer established art forms ref name kilkenny sweden serious film criticism spearheaded bengt idestam almquist point swedish film institute calling ''father swedish film criticism'' critics analyzing film merit value entertainment growing popularity medium caused major newspapers start hiring film critics ref name film industry saw audiences grow increasingly silent films accompanied sound however late audiences became influenced print news sources reporting movies


criticism became largely centered around audience reactions within theaters new forms criticism emerged essays analyzing films distinctive charm style sought persuade reader critic 's argument ref name emergence styles brought film criticism mainstream gaining attention many popular magazines made film reviews critiques eventual staple among print media decades passed fame critics grew gave rise household names among craft like james agee andrew sarris pauline


kael modern times roger ebert peter travers journalistic criticism film critics working newspapers magazines broadcast media online publications mainly review new releases although also review older films ref name classics ref important task reviews inform readers whether would want see film film review typically explain premise film discussing merits flaws verdict often summarized form rating numerous rating systems exist star scales academic style grades pictograms


''san francisco chronicle'' chicago critic roger ebert right director russ meyer well known journalistic critics included james agee ''time'' ''the nation'' vincent canby ''the new york times'' roger ebert ''chicago sun times'' mark kermode bbc ''the observer'' james berardinelli philip french ''the observer'' pauline kael ''the new yorker'' manny farber ''the new republic'' ''time'' ''the nation'' peter bradshaw ''the guardian'' michael phillips ''chicago tribune'' andrew sarris ''the village voice'' joel siegel ''good morning america'' jonathan rosenbaum ''chicago reader'' christy lemire ''what flick '' roger ebert gene siskel popularised concept reviewing films television


format show ''siskel ebert movies'' became syndicated critics established careers print media continued write written reviews newspapers alongside television show online film criticism aggregators websites rotten tomatoes metacritic seek improve usefulness film reviews compiling assigning score order gauge general reception film receives less well known aggregators movie review query engine mrqe also available online film critics blogging also introduced


opportunities new wave amateur film critics opinions heard review blogs may focus one genre director actor encompass much wider variety films friends friends friends strangers able visit blogsites often leave comments movie author 's review although much less frequented professional counterparts sites gather following like minded people look specific bloggers reviews found critic consistently exhibits outlook similar youtube


also served platform amateur film critics websites specialize narrow aspects film reviewing instance sites focus specific content advisories parents judge film 's suitability children others focus religious perspective eg cap alert still others highlight esoteric subjects depiction science fiction films one example ''insultingly stupid movie physics'' intuitor online niche websites provide comprehensive coverage independent sector usually adopting style closer print journalism tend prohibit advertisement offer uncompromising


opinions free commercial interest film critics normally academic film background ref name online film critics society international professional association internet based cinema reviewers consists writers world new york film critics online members handle reviews new york tri state area user submitted reviews community driven review sites allow internet users submit personal movie reviews allowed common movie goer express opinion films many sites allow users rate films scale rely star


people rather write mass market publications articles usually published scholarly journals texts tend affiliated university presses sometimes market magazines academic criticism film often follows similar format usually include summaries plot film either refresh plot reader reinforce idea repetition film 's genre tends discussions cultural context major themes repetitions details legacy film academic film criticism film studies


sequenced dedicated style way language art create meaning historical form criticism n't look direct things said culture surrounding environments given film historical critic create meaning something explicitly stated shown film psychoanalysis breaks unconscious one experience observing given film political economic looks economics politics depicted directly inside film also effects films creation


marketing screening sale academic film criticism tackles many aspects film making production well distribution disciplines include camera work digitalization lighting sound narratives dialogues themes genres among maty things academic film critics take consideration evaluate engaging critique notable academic film critics include andr bazin jean luc godard fran ois truffaut writers ''cahiers du cin ma'' kristin thompson david bordwell sergei eisenstein godard truffaut eisenstein also film directors issues controversies influence effect reviews film 's


box office performance dvd rentals sales become matter debate analysts argue modern movie marketing using pop culture convention appearances eg comicon social media along traditional means advertising led part decline readership many reviewers newspapers print publications fewer critics television radio last thirty years however recent years growing belief film industry critic aggregators especially rotten tomatoes increasing collective influence film critics underperformance several films


blamed low scores rotten tomatoes led studies one commissioned th century fox claiming younger viewers give website credibility major studio marketing undercuts effectiveness today fan run film analysis websites like box office prophets cinebee box office guru routinely factor opinions general public films produced undulating curve shifting expectations undulating curve shifting expectations ucose refers title recurring entertainment industry feature ''new york'' magazine


cultural critic adam sternbergh also concept media analysis co developed writer emily nussbaum ucose refers dynamic tension pre release promotional efforts subsequent audience reactions entertainment media ucose provides way analyzing trajectory entertainment products metamorphize way theorized seven stage growth chart pre buzz buzz rave reviews saturation point overhyped backlash finally backlash backlash female representation many complaints film criticism industry underrepresentation women ref name ref study top critics rotten tomatoes


two influential film critics internet led decline jobs small newspapers women likely review films whereas male dominated jobs major newspapers survived better internet also encouraged growth niche review websites even male dominated older media kilkenny also suggested shortage female critics related shortage female opinion columnists ref name kilkenny ref clem bastow culture writer ''the guardian australia'' discussed possible effects critical response film


''the intern'' received mixed reviews critics blockquote critical response ''the intern'' fascinating 's subset male critics clearly see nancy meyers code chick flick react according bile 's interesting though think female critics working industry coded male macho often feel need go hard certain films women presumably worry 'll dismissed critically speaking praise film like ''the intern'' though 're reviewing favorably 're women ref name


slightly likely rate film highly represents women well mainstream moviegoers turned films female protagonists movies represent women well likely profitable movies n't less risky business propositions salary movie critics earned yearly average salary american film critics earn us year newspaper magazine critics would make ref name bizfluent ref online movie critics would make per review ref name bizfluent tv critics would make


limit films see'' cappella books film criticism


name bueker https booksgooglecom booksid hsbjap fyc lpg pp dq ayurvedic balancing integration western fitness eastern wellness pg pa v onepage q six tastes f false ayurvedic balancing integration western fitness eastern wellness pages joyce bueker llewellyn worldwide ref oleogustus fattiness ref name oleogustus ref number food smells unbounded food 's flavor therefore easily altered changing smell keeping taste similar exemplified artificially flavored jellies soft drinks candies made bases similar taste dramatically different flavors due use different scents fragrances flavorings commercially produced food products typically created flavorists products intended consumed added


food order impart modify odour taste called flavorings flavourings flavorant flavour ant defined substance gives another substance taste altering characteristics solute causing become sweet sour tangy etc although terms common language denote combined chemical sensations taste smell terms used fragrance flavors industry refer edible chemicals extracts alter flavor food food products sense smell owing high cost unavailability natural


flavor extracts commercial flavorants nature identical means chemical equivalent natural flavors chemically synthesized rather extracted source materials identification components natural foods example raspberry may done using technology headspace techniques flavorist imitate flavor using chemicals present eu legislation term natural identical flavouring exist legislation specified flavouring natural flavouring flavor quality something affects sense


taste flavorants flavorings eu legislation defines several types flavorings flavoring substances including natural flavoring substances flavoring preparations definition always natural thermal process flavorings smoke flavorings flavor precursors flavorings three principal types flavorings used foods definitions agreed australia natural flavoring substances flavoring substances obtained plant animal raw materials physical microbiological enzymatic processes either used natural state processed human consumption cannot contain nature identical artificial flavoring substances nature identical flavoring substances obtained synthesis isolated


chemical processes chemically organoleptically identical flavoring substances naturally present products intended human consumption cannot contain artificial flavoring substances artificial flavoring substances identified natural product intended human consumption whether product processed typically produced fractional distillation additional chemical manipulation naturally sourced chemicals crude oil coal tar although chemically different sensory characteristics natural ones artificial flavors specific often complex mixtures singular naturally occurring flavor compounds combined


cinnamaldehyde cinnamon ethyl propionate fruity methyl anthranilate grape limonene orange ethyl decadienoate pear allyl hexanoate pineapple ethyl maltol sugar cotton candy dithiapentane truffle ethylvanillin vanilla methyl salicylate wintergreen compounds used produce artificial flavors almost identical occur naturally suggested artificial flavors may safer consume natural flavors due standards purity mixture consistency enforced either company law ref name smitha ref natural flavors contrast may contain impurities sources artificial


flavors typically pure required undergo testing sold consumption ref name smitha flavors food products usually result combination natural flavors set basic smell profile food product artificial flavors modify smell accent unlike smelling occurs upon inhalation sensing flavors mouth occurs exhalation phase breathing perceived differently individual words smell food different depending whether one smelling


entered one 's mouth taste eu legislation substances exclusively sweet sour salty taste considered flavorings article regulation ec umami savory flavorants commonly called taste flavor enhancers largely based amino acids nucleotides typically used sodium calcium salts umami flavorants recognized approved european union include nb considered flavorings eu legislation additives class wikitable acid salts description glutamic acid salts amino acid 's sodium salt monosodium glutamate msg one


sour tastes like salt sugar usually considered regulated flavorants law acid imparts slightly different sour tart taste alters flavor food class wikitable acid description formulation ph acetic acid gives vinegar sour taste distinctive smell ph ref name aqion ref ascorbic acid found oranges green peppers gives crisp slightly sour taste better known vitamin c ph ref name aqion citric acid found citrus fruits gives sour taste ph ref name aqion


fumaric acid found bolete mushrooms icelandic moss lichen found fruits used substitute citric tartaric acid enhances flavor sourness ph ref name aqion lactic acid found various milk fermented products give rich tartness ph ref name aqion malic acid found apples rhubarb gives sour tart taste ph phosphoric acid used cola drinks give acidic taste ph ref name aqion tartaric acid found grapes wines gives tart taste also


called racemic acid ph ref name aqion color color food affect one 's expectations flavor significantly one study adding red color drink increased perceived sweetness darker colored solutions rated better lighter ones though less sucrose concentration food manufacturers exploit phenomenon example different colors usa products froot loops cereal brands gummy bears often use flavorings restrictions regulations eu regulation ec flavorings certain food ingredients flavoring properties


use foods ie eu flavouring regulation adopted december entered force january applies january regulation ec lays general requirements safe use flavorings provides definitions different types flavorings regulation sets substances evaluation approval required union list flavoring substances approved use foods adopted october introduced annex regulation regulations natural flavoring eu


order labelled natural flavoring substance many conditions fulfilled natural flavouring substance shall mean flavouring substance obtained appropriate physical enzymatic microbiological processes material vegetable animal microbiological origin either raw state processing human consumption one traditional food preparation processes listed annex ii natural flavouring substances correspond substances naturally present identified nature detailed information production natural flavouring substances natural flavouring preparations found european flavour


associarion effa guidance document uk food law defines natural flavor ref uk follows eu legislation remains force december european union withdrawal act provides january directly applicable eu legislation converted uk law minor corrections enable operate effectively uk law corrections made statutory instrument uk food industry collaboration flavoring industry developed guidance consider declaring pictorial representation food ingredient


label pre packed product us code federal regulations describes natural flavorant ref dietary restrictions food manufacturers sometimes reluctant inform consumers source identity flavor ingredients whether produced incorporation substances animal byproducts flavor ingredients gelatin produced animal products glycerin derived either animal vegetable sources extracts vanilla may contain alcohol many groups jews jains hindus muslims well


foods contain generic natural flavors first determine source flavoring consuming food flavors may derived variety source products common allergens dairy soy sesame eggs nuts eu nevertheless information available labelling regulation eu provision food information consumers states article ingredient processing aid listed annex ii aforementioned regulation derived substance product listed annex ii causing allergies intolerances used


manufacture preparation food still present finished product even altered form must included labelling flavor creation food beverage companies may require flavors new products product line extensions eg low fat versions existing products changes formula processing existing products us billion generated sale flavors majority flavors used consumed processed packaged food flavors represent mixture aroma compounds raw material produced flavor companies


rare cases single synthetic compound used pure form artificial vanilla flavors vanillin ethylvanillin notable exception well artificial strawberry flavor ethyl methylphenylglycidate ubiquitous green apple aroma based hexyl acetate flavor creation done specially trained scientist called flavorist whose job combines scientific knowledge chemical palette creativity develop new distinctive flavors flavor creation begins flavorist receives brief client brief clients attempt communicate exactly type flavor sought


application used special requirements e g must natural communication barrier quite difficult overcome since people experienced describing flavors flavorist uses knowledge available chemical ingredients create formula compound electronic balance flavor submitted client testing several iterations feedback client may needed right flavor found additional work may also done flavor company example flavor company may


conduct sensory taste tests test consumer acceptance flavor sent client investigate sensory space flavor company may also employ application specialists work ensure flavor work application intended may require special flavor delivery technologies used protect flavor processing cooking flavor released eaten end consumer flavor obtained determined simple presence flavorant mixture flavorants


also concentrations thus even non flavored ingredient added removed food beverage noticeably affect final flavor dilutes otherwise changes concentrations remaining flavored ingredients determination standards available prepared sensory analysis flavors chemical analysis flavors solid phase extraction solid phase microextraction headspace gas chromatography applied extract separate flavor compounds sample determination typically done various mass spectrometric techniques flavor lexicon aid development objective language food


https wwwyoutubecom watchv qhm jrhmowi effa video flavouring scientific references j demyttenaere natural synthetic legal framework eu production natural flavouring ingredients biotechnology natural products schwab w lange bm w st eds springer jcr demyttenaere new european union flavouring regulation impact essential oils production natural flavouring ingredients maximum levels restricted substances flavour fragrance journal jcr demyttenaere eu regulation flavourings update years force focus b b labelling natural flavourings dealing restricted


substances foods food ingredients j jpn food science qualia


'''film theory''' set scholarly approaches within academic discipline film cinema studies began questioning formal essential attributes motion pictures provides conceptual frameworks understanding film 's relationship reality arts individual viewers society large film theory confused general film criticism film history though three disciplines interrelate although branches film theory derived linguistics literary theory also originated overlaps philosophy film history french philosopher henri bergson 's

Humanities
Performing arts
Film
Film theory


semiotics charles sanders peirce early film theory arose silent era mostly concerned defining crucial elements medium ricciotto canudo early italian film theoretician saw cinema plastic art motion gave cinema label sixth art later changed seventh art film theory largely evolved works directors like germaine dulac louis delluc jean epstein sergei eisenstein lev kuleshov dziga vertov film theorists like rudolf arnheim b la bal zs siegfried kracauer thinkers emphasized film differed reality


might considered valid art form years world war ii french film critic theorist andr bazin reacted approach cinema arguing film 's essence lay ability mechanically reproduce reality difference reality film theory took residence academia importing concepts established disciplines like psychoanalysis gender studies anthropology literary theory semiotics linguisticsas advanced scholars christian metz ref name metz ref however late early film theory ''per se'' achieve much


prominence american universities displacing prevailing humanistic auteur theory dominated cinema studies focused practical elements film writing production editing criticism ref name weddle weddle david http articleslatimescom print jul magazine tm filmschool lights camera action marxism semiotics narratology film school n't used one father discovers ''los angeles times'' july url retrieved jan ref american scholar david bordwell spoken many prominent developments film theory since uses derogatory term slab theory refer film studies based ideas ferdinand de saussure jacques


lacan louis althusser roland barthes ref name slab ref instead bordwell promotes describes neoformalism revival formalist film theory digital revolution image technologies influenced film theory various ways refocus onto celluloid film 's ability capture indexical image moment time theorists like mary ann doane philip rosen laura mulvey informed psychoanalysis psychoanalytical perspective lacanian notion real slavoj ek offered new aspects gaze extensively used contemporary film analysis


onward matrixial theory artist psychoanalyst bracha l ettinger revolutionized feminist film theory concept matrixial gaze established feminine gaze articulated differences phallic gaze relation feminine well maternal specificities potentialities coemergence offering critique sigmund freud 's jacques lacan 's psychoanalysis extensively used analysis films female authors like chantal akerman well male authors like pedro almodovar matrixial gaze offers female position subject object gaze


deconstructing structure subject offers border time border space possibility compassion witnessing ettinger 's notions articulate links aesthetics ethics trauma also historical revisiting early cinema screenings practices spectatorship modes writers tom gunning miriam hansen yuri tsivian ''critical cinema beyond theory practice'' clive meyer suggests 'cinema different experience watching film home art gallery' argues film theorists engage specificity philosophical concepts cinema medium distinct


others specific theories film see also film film film studies glossary motion picture terms invisible auditor list film periodicals narrative film philosophy film references reading dudley andrew ''concepts film theory'' oxford new york oxford university press dudley andrew ''the major film theories introduction'' oxford new york oxford university press francesco casetti ''theories cinema '' austin university texas press stanley cavell https booksgooglecom booksid ro ozngdzqc printsec frontcover dq stanley cavell ei nso snm eibmywsb aiuaw sig acfu u cbje tkhfu oa bubmh dafqxq ppp ''the world viewed reflections ontology film'' nd enlarged edn bill nichols ''representing reality issues concepts documentary'' bloomington indiana


'''fluid mechanics''' branch physics concerned mechanics fluids liquids gases plasmas forces applications wide range disciplines including mechanical civil chemical biomedical engineering geophysics oceanography meteorology astrophysics biology divided fluid statics study fluids rest fluid dynamics study effect forces fluid motion branch continuum mechanics subject models matter without using information made atoms models matter

Applied science
Engineering and technology
Mechanical Engineering
Fluid mechanics


buoyancy formulated famous law known archimedes' principle published work ''on floating bodies'' generally considered first major work fluid mechanics rapid advancement fluid mechanics began leonardo da vinci observations experiments evangelista torricelli invented barometer isaac newton investigated viscosity blaise pascal researched hydrostatics formulated pascal 's law continued daniel bernoulli introduction mathematical fluid dynamics ''hydrodynamica'' inviscid flow analyzed various mathematicians jean le rond d'alembert joseph louis lagrange pierre simon laplace sim denis poisson viscous flow


explored multitude engineers including jean l onard marie poiseuille gotthilf hagen mathematical justification provided claude louis navier george gabriel stokes navier stokes equations boundary layers investigated ludwig prandtl theodore von k rm n various scientists osborne reynolds andrey kolmogorov geoffrey ingram taylor advanced understanding fluid viscosity turbulence main branches fluid statics fluid statics '''hydrostatics''' branch fluid mechanics studies fluids rest embraces study conditions fluids rest stable equilibrium


contrasted fluid dynamics study fluids motion hydrostatics offers physical explanations many phenomena everyday life atmospheric pressure changes altitude wood oil float water surface water always level whatever shape container hydrostatics fundamental hydraulics engineering equipment storing transporting using fluids also relevant aspects geophysics astrophysics example understanding plate tectonics anomalies earth 's gravitational field meteorology medicine context blood


pressure many fields fluid dynamics ''fluid dynamics'' subdiscipline fluid mechanics deals ''fluid flow'' science liquids gases motion fluid dynamics offers systematic structure underlies practical disciplines embraces empirical semi empirical laws derived flow measurement used solve practical problems solution fluid dynamics problem typically involves calculating various properties fluid velocity pressure density temperature functions space time several subdisciplines including ''aerodynamics'' study air gases motion ''hydrodynamics''


study liquids motion fluid dynamics wide range applications including calculating forces movements aircraft determining mass flow rate petroleum pipelines predicting evolving weather patterns understanding nebulae interstellar space modeling explosions fluid dynamical principles used traffic engineering crowd dynamics relationship continuum mechanics fluid mechanics subdiscipline continuum mechanics illustrated following table mechanical view fluid substance support shear stress fluid rest shape


containing vessel fluid rest shear stress assumptions balance integrated fluid quantity control volume enclosed control surface assumptions inherent fluid mechanical treatment physical system expressed terms mathematical equations fundamentally every fluid mechanical system assumed obey conservation mass conservation energy conservation momentum continuum assumption example assumption mass conserved means fixed control volume example spherical volume enclosed control surface rate change mass contained


volume equal rate mass passing surface ''outside'' ''inside'' minus rate mass passing ''inside'' ''outside'' expressed equation integral form control volume '''''' idealization continuum mechanics fluids treated continuous even though microscopic scale composed molecules continuum assumption macroscopic observed measurable properties density pressure temperature bulk velocity taken well defined infinitesimal volume elements small comparison


characteristic length scale system large comparison molecular length scale fluid properties vary continuously one volume element another average values molecular properties continuum hypothesis lead inaccurate results applications like supersonic speed flows molecular flows nano scale ref name greenkorn ref problems continuum hypothesis fails solved using statistical mechanics determine whether continuum hypothesis applies knudsen number defined ratio molecular mean free path characteristic length scale evaluated problems


knudsen numbers evaluated using continuum hypothesis molecular approach statistical mechanics applied find fluid motion larger knudsen numbers navier stokes equations '''navier stokes equations''' named claude louis navier george gabriel stokes differential equations describe force balance given point within fluid incompressible fluid vector velocity field math mathbf u math navier stokes equations math frac partial mathbf u partial mathbf u cdot nabla mathbf u frac rho nabla p nu nabla mathbf u math differential equations analogues deformable materials newton 's


global weather systems aerodynamics hydrodynamics many solutions navier stokes equations currently found help computers branch science called computational fluid dynamics inviscid viscous fluids '''inviscid fluid''' viscosity math nu math practice inviscid flow idealization one facilitates mathematical treatment fact purely inviscid flows known realized case superfluidity otherwise fluids generally '''viscous''' property often important within boundary layer near solid surface flow must match


onto slip condition solid cases mathematics fluid mechanical system treated assuming fluid outside boundary layers inviscid matching solution onto thin laminar boundary layer fluid flow porous boundary fluid velocity discontinuous free fluid fluid porous media related beavers joseph condition useful low subsonic speeds assume gas incompressible density gas change


even though speed static pressure change newtonian versus non newtonian fluids '''newtonian fluid''' named isaac newton defined fluid whose shear stress linearly proportional velocity gradient direction perpendicular plane shear definition means regardless forces acting fluid ''continues flow'' example water newtonian fluid continues display fluid properties matter much stirred mixed slightly less rigorous definition drag small object moved slowly


fluid proportional force applied object compare friction important fluids like water well gases behave good approximation newtonian fluid normal conditions earth contrast stirring non newtonian fluid leave hole behind gradually fill time behavior seen materials pudding oobleck sand although sand n't strictly fluid alternatively stirring non newtonian fluid cause viscosity decrease fluid appears thinner seen non drip paints many types non newtonian fluids


defined something fails obey particular property example fluids long molecular chains react non newtonian manner equations newtonian fluid constant proportionality viscous stress tensor velocity gradient known viscosity simple equation describe incompressible newtonian fluid behavior math tau mu frac dv dy math math tau math shear stress exerted fluid drag math mu math fluid viscosity constant proportionality math frac dv dy math velocity gradient perpendicular direction shear newtonian fluid viscosity definition depends


temperature pressure forces acting upon fluid incompressible equation governing viscous stress cartesian coordinates math tau ij mu left frac partial v partial x j frac partial v j partial x right mu partial v j math math tau ij math shear stress math th math face fluid element math j th math direction math v math velocity math th math direction math x j math math j th math direction coordinate fluid incompressible general form viscous stress newtonian fluid math tau ij mu left frac partial v partial x j frac partial v j partial x frac delta ij


nabla cdot mathbf v right kappa delta ij nabla cdot mathbf v math math kappa math second viscosity coefficient bulk viscosity fluid obey relation termed non newtonian fluid several types non newtonian fluids either plastic bingham plastic pseudoplastic dilatant thixotropic rheopectic viscoelastic applications another rough broad division among fluids made ideal non ideal fluids ideal fluid non viscous offers resistance whatsoever shearing force ideal fluid really exist calculations assumption


justifiable one example flow far solid surfaces many cases viscous effects concentrated near solid boundaries boundary layers regions flow field far away boundaries viscous effects neglected fluid treated inviscid ideal flow viscosity neglected term containing viscous stress tensor math mathbf tau math navier stokes equation vanishes equation reduced form called euler equation see also aerodynamics applied mechanics bernoulli 's principle communicating vessels computational


fluid dynamics compressor map secondary flow different types boundary conditions fluid dynamics references ref ref name batchelor ref reading external links http wwwfreebookcentrenet physics fluid mechanics bookshtml free fluid mechanics books http arjournalsannualreviewsorg loi fluid annual review fluid mechanics http wwwcfd onlinecom wiki main page cfdwiki computational fluid dynamics reference wiki http wwwinteractiveflowscom downloads educational particle image velocimetry resources demonstrations civil engineering


'''family law''' also called '''matrimonial law''' ''law domestic relations'' area law deals family matters domestic relations ref name abafl ref overview subjects commonly fall nation 's body family law include marriage civil unions domestic partnerships entry legally recognized spousal domestic relationships ref name abafl termination legally recognized family relationships ancillary matters including divorce annulment property settlements alimony child custody visitation child support alimony awards adoption proceedings adopt child cases adult surrogacy law process giving


definitions family hongik university journal law vol https wwwduxburyetchk book hong kong family court tables includes summary hong kong family law principles guide recent case law relevant statutes glossary relevant terms related hong kong family law divorce marriage


computer science '''functional programming''' programming paradigm programs constructed applying composing functions declarative programming paradigm function definitions trees expressions map values values rather sequence imperative statements update running state program functional programming functions treated first class citizens meaning bound names including local identifiers passed arguments returned functions data type allows programs written declarative composable

Formal science
Computer science
Programming languages
Functional programming


style small functions combined modular manner functional programming sometimes treated synonymous purely functional programming subset functional programming treats functions deterministic mathematical functions pure functions pure function called given arguments always return result cannot affected mutable state side effects contrast impure procedures common imperative programming side effects modifying program 's state taking input user proponents purely functional programming claim


restricting side effects programs fewer bugs easier debug test suited formal verification ref name hudak ref ref name hugheswhyfpmatters functional programming roots academia evolving lambda calculus formal system computation based functions functional programming historically less popular imperative programming many functional languages seeing use today industry education including common lisp scheme ref name clinger ref name hartheimer ref name kidd ref name cleis clojure wolfram language ref name referencewolframcom ref ref name amath co racket ref name racket video games erlang ref name erlang faq ref name armstrong ref name larson elixir ocaml ref name minksy ref name leroy haskell ref name haskell industry


rust raku scala ref name effective scala java since java ref name java javadoc history lambda calculus developed alonzo church formal system computation built function application alan turing proved lambda calculus turing machines equivalent models computation showing lambda calculus turing complete lambda calculus forms basis functional programming languages equivalent theoretical formulation combinatory logic developed moses sch nfinkel haskell curry church later developed weaker system simply typed lambda calculus extended


offshoots dylan julia sought simplify rationalise lisp around cleanly functional core common lisp designed preserve update paradigmatic features numerous older dialects replaced information processing language ipl sometimes cited first computer based functional programming language assembly style language manipulating lists symbols notion ''generator'' amounts function accepts function argument since assembly level language code data ipl regarded higher order functions


however relies heavily mutating list structure similar imperative features kenneth e iverson developed apl early described book ''a programming language'' apl primary influence john backus 's fp early iverson roger hui created j mid arthur whitney previously worked iverson created k used commercially financial industries along descendant q john backus presented fp turing award lecture programming liberated von neumann style functional style algebra


programs ref name backus ref defines functional programs built hierarchical way means combining forms allow algebra programs modern language means functional programs follow principle compositionality backus 's paper popularized research functional programming though emphasized function level programming rather lambda calculus style associated functional programming language ml created robin milner university edinburgh david turner developed language sasl university st andrews also edinburgh burstall darlington developed


functional language npl npl based kleene recursion equations first introduced work program transformation burstall macqueen sannella incorporated polymorphic type checking ml produce language hope ml eventually developed several dialects common ocaml standard ml guy l steele gerald jay sussman developed scheme described lambda papers textbook ''structure interpretation computer programs'' scheme first dialect lisp use lexical scoping require tail call optimization features


restriction use thus first class functions appear anywhere program first class entities like numbers including arguments functions return values higher order functions enable partial application currying technique applies function arguments one time application returning new function accepts next argument lets programmer succinctly express example successor function addition operator partially applied natural number one pure functions pure functions expressions side effects memory


means pure functions several useful properties many used optimize code result pure expression used removed without affecting expressions pure function called arguments cause side effects result constant respect argument list sometimes called referential transparency idempotence ie calling pure function arguments returns result enable caching optimizations memoization data dependency two pure expressions order


external functions compilers gcc add extra keywords programmer explicitly mark external functions pure enable optimizations fortran also lets functions designated ''pure'' ref name fortran ref c added code constexpr code keyword similar semantics recursion iteration looping functional languages usually accomplished via recursion recursive functions invoke letting operation repeated reaches base case general recursion requires maintaining stack consumes space linear amount depth recursion could make recursion prohibitively expensive use instead imperative loops


however special form recursion known tail recursion recognized optimized compiler code used implement iteration imperative languages tail recursion optimization implemented transforming program continuation passing style compiling among approaches scheme language standard requires implementations support proper tail recursion meaning must allow unbounded number active tail calls ref name 'schemepropertailrec' ref proper tail recursion simply optimization language feature assures users use recursion express loop would


safe space moreover contrary name accounts tail calls tail recursion proper tail recursion usually implemented turning code imperative loops implementations might implement ways example chicken intentionally maintains stack lets stack overflow however happens garbage collector claim space back allowing unbounded number active tail calls even though turn tail recursion loop common patterns recursion abstracted away using higher order functions catamorphisms anamorphisms folds unfolds


obvious examples recursion schemes play role analogous built control structures loops imperative languages general purpose functional programming languages allow unrestricted recursion turing complete makes halting problem undecidable cause unsoundness equational reasoning generally requires introduction inconsistency logic expressed language 's type system special purpose languages coq allow well founded recursion strongly normalizing nonterminating computations expressed infinite streams values called codata consequence languages fail turing complete


expressing certain functions impossible still express wide class interesting computations avoiding problems introduced unrestricted recursion functional programming limited well founded recursion constraints called total functional programming ref name totalfp ref strict versus non strict evaluation functional languages categorized whether use ' 'strict eager '' ''non strict lazy '' evaluation concepts refer function arguments processed expression evaluated technical difference denotational semantics expressions containing failing divergent computations strict evaluation evaluation


term containing failing subterm fails example expression print length fails strict evaluation division zero third element list lazy evaluation length function returns value ie number items list since evaluating attempt evaluate terms making list brief strict evaluation always fully evaluates function arguments invoking function lazy evaluation evaluate function arguments unless values required evaluate function call usual implementation strategy


lazy evaluation functional languages graph reduction lazy evaluation used default several pure functional languages including miranda clean haskell argues lazy evaluation mechanism improving program modularity separation concerns easing independent implementation producers consumers data streams ref name hugheswhyfpmatters ref launchbury describes difficulties lazy evaluation introduces particularly analyzing program 's storage requirements proposes operational semantics aid analysis ref name launchbury ref harper proposes including strict lazy evaluation language using language 's type system distinguish


type systems especially since development hindley milner type inference functional programming languages tended use typed lambda calculus rejecting invalid programs compilation time risking false positive errors opposed untyped lambda calculus accepts valid programs compilation time risks false negative errors used lisp variants scheme though reject invalid programs runtime information enough reject valid programs use algebraic datatypes makes manipulation complex data structures convenient presence


strong compile time type checking makes programs reliable absence reliability techniques like test driven development type inference frees programmer need manually declare types compiler cases research oriented functional languages coq agda cayenne epigram based intuitionistic type theory lets types depend terms types called dependent types type systems decidable type inference difficult understand program dependent types express arbitrary propositions higher order logic curry howard isomorphism well typed programs


glasgow haskell compiler ocaml scala proposed additions languages including java c referential transparency functional programs assignment statements value variable functional program never changes defined eliminates chances side effects variable replaced actual value point execution functional programs referentially transparent consider c assignment statement code x x code changes value assigned variable code x code let us say initial


value code x code code code two consecutive evaluations variable code x code yields code code code code respectively clearly replacing code x x code either code code code code gives program different meaning expression ''is not'' referentially transparent fact assignment statements never referentially transparent consider another function syntaxhighlight lang c inline int plusone int x return x syntaxhighlight ''is'' transparent implicitly change input x thus side effects functional programs exclusively use type function therefore referentially transparent data structures purely functional


data structures often represented different way imperative counterparts example array constant access update times basic component imperative languages many imperative data structures hash table binary heap based arrays arrays replaced maps random access lists admit purely functional implementation logarithmic access update times purely functional data structures persistence property keeping previous versions data structure unmodified clojure persistent data structures used functional alternatives imperative


counterparts persistent vectors example use trees partial updating calling insert method result nodes created comparison imperative programming functional programming different imperative programming significant differences stem fact functional programming avoids side effects used imperative programming implement state pure functional programming completely prevents side effects provides referential transparency higher order functions rarely used older imperative programming traditional imperative program might use loop traverse modify list functional program


hand would probably use higher order map function takes function list generating returning new list applying function list item imperative vs functional programming following two examples written javascript achieve effect multiply even numbers array add storing final sum variable result traditional imperative loop syntaxhighlight lang javascript const numlist let result let numlistlength


way pure functional programming language haskell implements using monads derived category theory monads offer way abstract certain types computational patterns including limited modeling computations mutable state side effects imperative manner without losing purity existing monads may easy apply program given appropriate templates examples many students find difficult understand conceptually eg asked define new monads sometimes needed certain types libraries functional languages also simulate states passing around immutable


modern research languages use effect systems make presence side effects explicit efficiency issues functional programming languages typically less efficient use cpu memory imperative languages c pascal related fact mutable data structures like arrays straightforward implementation using present hardware flat arrays may accessed efficiently deeply pipelined cpus prefetched efficiently caches complex pointer chasing handled simd instructions also easy create equally efficient general purpose


immutable counterparts purely functional languages worst case slowdown logarithmic number memory cells used mutable memory represented purely functional data structure logarithmic access time balanced tree ref name spiewak however slowdowns universal programs perform intensive numerical computations functional languages ocaml clean slightly slower c according computer language benchmarks game programs handle large matrices multidimensional databases array functional languages j k designed speed optimizations immutability data


many cases lead execution efficiency allowing compiler make assumptions unsafe imperative language thus increasing opportunities inline expansion lazy evaluation may also speed program even asymptotically whereas may slow constant factor however may introduce memory leaks used improperly launchbury ref name launchbury discusses theoretical issues related memory leaks lazy evaluation o'sullivan ''et al'' give practical advice analyzing fixing however general implementations lazy evaluation making extensive use dereferenced code data


perform poorly modern processors deep pipelines multi level caches cache miss may cost hundreds cycles functional programming non functional languages possible use functional style programming languages traditionally considered functional languages example fortran ref name fortran explicitly support pure functions javascript lua python go first class functions inception python support lambda map reduce filter well closures python though python relegated reduce code functools code standard


library module first class functions introduced mainstream languages php visual basic c c kotlin ref name php anonymous classes closures lambdas fully supported libraries language extensions immutable data structures developed aid programming functional style java anonymous classes sometimes used simulate closures however anonymous classes always proper replacements closures limited capabilities java supports lambda expressions replacement anonymous classes c anonymous classes necessary


closures lambdas fully supported libraries language extensions immutable data structures developed aid programming functional style c many object oriented design patterns expressible functional programming terms example strategy pattern simply dictates use higher order function visitor pattern roughly corresponds catamorphism fold similarly idea immutable data functional programming often included imperative programming languages example tuple python immutable array objectfreeze javascript applications spreadsheets spreadsheets considered


form pure zeroth order strict evaluation functional programming system ref name wakeling ref however spreadsheets generally lack higher order functions well code reuse implementations also lack recursion several extensions developed spreadsheet programs enable higher order reusable functions far remain primarily academic nature ref name excel ref academia functional programming active area research field programming language theory several peer reviewed publication venues focusing functional programming including international conference functional programming journal functional programming symposium trends functional programming


name clinger ref name hartheimer applied problems training simulation software ref name kidd telescope control ref name cleis ocaml introduced mid seen commercial use areas financial analysis ref name minksy driver verification industrial robot programming static analysis embedded software ref name leroy haskell though initially intended research language ref name hudak also applied range companies areas aerospace systems hardware design web programming ref name haskell industry ref name hudak functional programming languages seen use industry include scala f ref name 'quantfsharp' ref name 'businessappsfsharp' wolfram language ref name referencewolframcom lisp standard ml


clojure functional platforms popular finance risk analytics particularly larger investment banks risk factors coded functions form interdependent graphs categories measure correlations market shifts unlike gr bner basis optimizations also regulatory compliance comprehensive capital analysis review given use ocaml caml variations finance systems sometimes considered related categorical abstract machine cam indeed functional programming heavily influenced category theory education many universities teach taught functional programming part undergraduate


computer science degrees ref name oxfordfp ref ref name imperialfp ref ref name nottinghamfp ref ref name mitfp ref use introduction programming ref name mitfp others teach teaching imperative programming ref name nottinghamfp ref name ref outside computer science functional programming used method teach problem solving algebra geometric concepts ref name bootstrapworld ref also used tool teach classical mechanics ''structure interpretation classical mechanics'' see also purely functional programming comparison programming paradigms eager evaluation list functional programming topics nested function inductive functional programming functional reactive programming references ref ref name hartheimer ref ref name kidd ref


ref name cleis ref ref name erlang faq ref ref name armstrong ref ref name larson ref ref name minksy ref ref name leroy ref ref name haskell industry ref ref name effective scala ref ref name java javadoc ref ref name racket video games ref ref name hudak ref ref name user ref ref name chambers ref ref name amath co ref ref name novatchev ref ref name mertz ref ref name chamberlin boyce ref ref name sim diasca ref ref name spiewak ref reading cousineau guy michel mauny ''the functional approach programming'' cambridge uk cambridge university press curry haskell brooks feys robert craig william ''combinatory logic'' volume north holland publishing company amsterdam dominus mark jason '' http hopperlplovercom book pdf higherorderperlpdf higher order perl '' morgan kaufmann graham paul ''ansi common lisp'' englewood cliffs new jersey prentice hall maclennan bruce j ''functional programming practice


theory'' addison wesley pratt terrence w marvin v zelkowitz ''programming languages design implementation'' rd ed englewood cliffs new jersey prentice hall salus peter h ''functional logic programming languages'' vol handbook programming languages indianapolis indiana macmillan technical publishing thompson simon ''haskell craft functional programming'' harlow england addison wesley longman limited external links introduction ''functional programming python'' david mertz http gnosiscx publish programming charming python html part http gnosiscx publish programming charming python html part http gnosiscx publish programming charming python html part programming paradigms articles example c code


typical aerodynamic teardrop shape assuming viscous medium passing left right diagram shows pressure distribution thickness black line shows velocity boundary layer violet triangles green vortex generators prompt transition turbulent flow prevent back flow also called flow separation high pressure region back surface front smooth possible even employs shark like skin turbulence increases energy airflow truncation right known kammback also prevents backflow


high pressure region back across spoilers convergent part physics engineering '''fluid dynamics''' subdiscipline fluid mechanics describes '''flow''' fluids liquids gases several subdisciplines including ''aerodynamics'' study air gases motion '''hydrodynamics''' study liquids motion fluid dynamics wide range applications including calculating forces moments aircraft determining mass flow rate petroleum pipelines predicting weather patterns understanding nebulae interstellar space modelling fission weapon detonation fluid dynamics offers


systematic structure underlies practical disciplines embraces empirical semi empirical laws derived flow measurement used solve practical problems solution fluid dynamics problem typically involves calculation various properties fluid flow velocity pressure density temperature functions space time twentieth century ''hydrodynamics'' synonymous fluid dynamics still reflected names fluid dynamics topics like magnetohydrodynamics hydrodynamic stability also applied gases equations foundational axioms fluid dynamics conservation laws specifically


conservation mass conservation linear momentum conservation energy also known first law thermodynamics based classical mechanics modified quantum mechanics general relativity expressed using reynolds transport theorem addition fluids assumed obey continuum assumption fluids composed molecules collide one another solid objects however continuum assumption assumes fluids continuous rather discrete consequently assumed properties density pressure temperature flow velocity well defined infinitesimally small


points space vary continuously one point another fact fluid made discrete molecules ignored fluids sufficiently dense continuum contain ionized species flow velocities small relation speed light momentum equations newtonian fluids navier stokes equations non linear set differential equations describes flow fluid whose stress depends linearly flow velocity gradients pressure unsimplified equations general closed form solution primarily


use computational fluid dynamics equations simplified several ways make easier solve simplifications allow simple fluid dynamics problems solved closed form addition mass momentum energy conservation equations thermodynamic equation state gives pressure function thermodynamic variables required completely describe problem example would perfect gas equation state math p frac rho r u math pressure density absolute temperature


yield expression may interpreted integral form law applied infinitesimally small volume point within flow ref translated integral form continuity equation math frac partial partial iiint v rho dv math oiint preintegral intsubscpt math scriptstyle math integrand math rho mathbf u cdot mathbf math fluid density flow velocity vector time left hand side expression rate increase mass within volume contains triple integral


fluid within control volume due net flow momentum volume action external forces acting fluid within volume math frac partial partial iiint scriptstyle v rho mathbf u dv math oiint preintegral intsubscpt math scriptstyle math integrand math rho mathbf u cdot mathbf mathbf u math oiint intsubscpt math scriptstyle math integrand math p mathbf math math displaystyle iiint scriptstyle v rho mathbf f text body dv mathbf f text surf math integral formulation equation term left net change momentum within volume first


term right net rate momentum convected volume second term right force due pressure volume 's surfaces first two terms right negated since momentum entering system accounted positive normal opposite direction velocity pressure forces third term right net acceleration mass within volume due body forces represented surface forces viscous forces represented


net force due shear forces acting volume surface momentum balance also written ''moving'' control volume following differential form momentum conservation equation volume reduced infinitesimally small point surface body forces accounted one total force example may expanded expression frictional gravitational forces acting point flow math frac mathbf u mathbf f frac nabla p rho math aerodynamics air assumed


newtonian fluid posits linear relationship shear stress due internal friction forces rate strain fluid equation vector equation three dimensional flow expressed three scalar equations three coordinate directions conservation momentum equations compressible viscous flow case called navier stokes equations ref name jd anderson defn although energy converted one form another total energy closed system remains constant math rho frac dh dt frac p nabla cdot left


k nabla right phi math specific enthalpy thermal conductivity fluid temperature viscous dissipation function viscous dissipation function governs rate mechanical energy flow converted heat second law thermodynamics requires dissipation term always positive viscosity cannot create energy within control volume expression left side material derivative classifications compressible versus incompressible flow fluids compressible extent changes pressure


temperature cause changes density however many situations changes pressure temperature sufficiently small changes density negligible case flow modelled incompressible flow otherwise general compressible flow equations must used mathematically incompressibility expressed saying density fluid parcel change moves flow field math frac mathrm rho mathrm math material derivative sum local convective derivatives additional constraint simplifies


waves involving changes pressure density medium propagate newtonian versus non newtonian fluids flow around airfoil fluids viscous meaning exert resistance deformation neighbouring parcels fluid moving different velocities exert viscous forces velocity gradient referred strain rate dimensions isaac newton showed many familiar fluids water air stress due viscous forces linearly related strain rate fluids called newtonian fluids coefficient proportionality


called fluid 's viscosity newtonian fluids fluid property independent strain rate non newtonian fluids complicated non linear stress strain behaviour sub discipline rheology describes stress strain behaviours fluids include emulsions slurries viscoelastic materials blood polymers ' 'sticky liquids'' latex honey lubricants inviscid versus viscous versus stokes flow dynamic fluid parcels described help newton 's second law accelerating parcel fluid subject inertial effects reynolds number dimensionless quantity


characterises magnitude inertial effects compared magnitude viscous effects low reynolds number indicates viscous forces strong compared inertial forces cases inertial forces sometimes neglected flow regime called stokes creeping flow contrast high reynolds numbers indicate inertial effects effect velocity field viscous friction effects high reynolds number flows flow often modeled inviscid flow approximation viscosity completely neglected eliminating viscosity allows navier stokes equations simplified


euler equations integration euler equations along streamline inviscid flow yields bernoulli 's equation addition inviscid flow irrotational everywhere bernoulli 's equation completely describe flow everywhere flows called potential flows velocity field may expressed gradient potential energy expression idea work fairly well reynolds number high however problems involving solid boundaries may require viscosity included viscosity cannot neglected near solid boundaries slip condition generates


thin region large strain rate boundary layer viscosity effects dominate thus generates vorticity therefore calculate net forces bodies wings viscous flow equations must used inviscid flow theory fails predict drag forces limitation known d'alembert 's paradox commonly used model especially computational fluid dynamics use two flow models euler equations away body boundary layer equations region close body two solutions matched using method matched asymptotic expansions


steady versus unsteady flow hydrodynamics simulation rayleigh taylor instability flow function time called '' 'steady flow''' steady state flow refers condition fluid properties point system change time time dependent flow known unsteady also called transient whether particular flow steady unsteady depend chosen frame reference instance laminar flow sphere steady frame reference stationary respect sphere frame reference