speaking hindu tradition africa partly also latin america debate bioethics frequently focuses practical relevance context underdevelopment geopolitical power relations africa bioethical approach influenced similar western bioethics due colonization many african countries ref name african bioethicists calling shift bioethics utilizes indigenous african philosophy rather western philosophy african bioethicists also believe africans likely accept bioethical approach grounded culture well empower african


people ref name ref masahiro morioka argues japan bioethics movement first launched disability activists feminists early academic bioethics began mid period unique philosophical discussions brain death disability appeared academy journalism chinese culture bioethics much emphasis autonomy opposed heavy emphasis placed autonomy western bioethics community social values family heavily valued chinese culture contribute lack emphasis autonomy chinese bioethics


chinese believe family community individual interdependent common family unit collectively make decisions regarding healthcare medical decisions loved one instead individual making independent decision self argue spirituality understanding one another spiritual beings moral agents important aspect bioethics spirituality bioethics heavily intertwined one another healthcare provider important know understand varying world views religious beliefs knowledge


understanding empower healthcare providers ability better treat serve patients developing connection understanding patient 's moral agent helps enhance care provided patient without connection understanding patients risk becoming faceless units work looked set medical conditions opposed storied spiritual beings ref name pmid ref islamic bioethics bioethics realm islam differs western bioethics share similar perspectives viewpoints well western bioethics focused rights


especially individual rights islamic bioethics focuses religious duties obligations seeking treatment preserving life islamic bioethics heavily influenced connected teachings qur'an well teachings prophet muhammad influences essentially make extension shariah islamic law islamic bioethics passages qur'an often used validate various medical practices example passage qur'an states whosoever killeth human shall killed humankind whosoever saveth life one shall


saved life humankind excerpt used encourage using medicine medical practices save lives also looked protest euthanasia assisted suicide high value worth placed human life islam turn human life deeply valued practice islamic bioethics well muslims believe human life even one poor quality needs given appreciation must cared conserved react new technological medical advancements informed islamic jurists


regularly hold conferences discuss new bioethical issues come agreement stand issue islamic perspective allows islamic bioethics stay pliable responsive new advancements medicine ref name pmid ref standpoints taken islamic jurists bioethical issues always unanimous decisions times may differ much diversity among muslims varying country country different degrees adhere shariah differences disagreements regards jurisprudence theology ethics two main branches islam sunni shia


lead differences methods ways islamic bioethics practiced throughout islamic world area lack consensus brain death organization islamic conferences islamic fiqh academy oic ifa holds view brain death equivalent cardiopulmonary death acknowledges brain death individual individual deceased contrary islamic organization medical sciences ioms states brain death intermediate state life death acknowledge brain dead individual deceased ref name ref islamic bioethicists look


qur'an religious leaders regarding outlook reproduction abortion firmly believed reproduction human child proper legitimate via marriage mean child reproduced via sexual intercourse married couple proper legitimate way child act husband wife okay married couple child artificially techniques using modern biotechnology opposed sexual intercourse


context marriage would deemed immoral islamic bioethics strongly abortion strictly prohibits ioms states moment zygote settles inside woman 's body deserves unanimously recognized degree respect abortion may permitted unique situations considered lesser evil ref name feminist bioethics feminist bioethics critiques fields bioethics medicine lack inclusion women marginalized group 's perspectives ref name ref lack perspective women thought create power imbalances favor men ref


name ref power imbalances theorized created androcentric nature medicine ref name one example lack consideration women clinical drug trials exclude women due hormonal fluctuations possible future birth defects ref name office research women 's health url https orwhodnihgov toolkit recruitment history access date website orwhodnihgov ref led gap research pharmaceuticals affect women ref name feminist bioethicists call necessity feminist approaches bioethics lack diverse perspectives bioethics medicine cause preventable harm already vulnerable groups ref name


study first gained prevalence field reproductive medicine viewed woman 's issue ref name since feminist approaches bioethics expanded include bioethical topics mental health disability advocacy healthcare accessibility pharmaceuticals ref name lindemann notes need future agenda feminist approaches bioethics expand include healthcare organizational ethics genetics stem cell research ref name notable figures feminist bioethics include carol gillian susan sherwin creators ''international journal feminist approaches bioethics'' mary c rawlinson


scientists making changes genes building blocks human body ref name ref currently therapeutic gene therapy available treat specific genetic disorders editing cells specific body parts example gene therapy treat hematopoietic disease also controversial gene therapy called germline gene therapy genes sperm egg edited prevent genetic disorder future generation unknown type gene therapy affects long term human development united states federal funding cannot used research germline gene therapy ref name


education bioethics taught courses undergraduate graduate level different academic disciplines programs philosophy medicine law social sciences become requirement professional accreditation many health professional programs medicine nursing rehabilitation obligatory training ethics eg professional ethics medical ethics clinical ethics nursing ethics interest field professional opportunities led development dedicated programs concentrations bioethics largely united states europe offering undergraduate majors minors graduate certificates master 's doctoral degrees every medical school canada teaches


bioethics students gain understanding biomedical ethics use knowledge gained future careers provide better patient care canadian residency training programs required teach bioethics one conditions accreditation requirement college family physicians canada royal college physicians surgeons canada ref name pmid ref criticism study bioethics also drawn criticism instance paul farmer noted bioethics tends focus attention problems arise much care patients industrialized


nations giving little attention ethical problem little care poor ref name farmer ref farmer characterizes bioethics handling morally difficult clinical situations normally hospitals industrialized countries quandary ethics ref name farmer regard quandary ethics clinical bioethics unimportant argues rather bioethics must balanced give due weight poor additionally bioethics condemned lack diversity thought particularly concerning race even field grown include areas public opinion policymaking


medical decision making little academic writing authored concerning intersection race especially cultural values imbued construct bioethical literature john hoberman illustrates critique points bioethicists traditionally resistant expanding discourse include sociological historically relevant applications central notion white normativity establishes dominance white hegemonic structures bioethical academia tends reinforce existing biases however differing views bioethics' lack diversity thought social inclusivity also advanced thought historian heikki


event horizon ref name apjl animated simulation schwarzschild black hole galaxy passing behind plane perpendicular line sight around time exact alignment syzygy extreme gravitational lensing galaxy black hole observed '''black hole''' region spacetime gravity strong nothing particles even electromagnetic radiation light escape theory general relativity predicts sufficiently compact mass deform spacetime form black hole ref name wald ref ref name nyt ref boundary

Natural science
Space science
Astrophysics
Black holes


escape called event horizon although enormous effect fate circumstances object crossing according general relativity locally detectable features ref name hamiltona ref many ways black hole acts like ideal black body reflects light moreover quantum field theory curved spacetime predicts event horizons emit hawking radiation spectrum black body temperature inversely proportional mass temperature order billionths kelvin black holes stellar mass making


essentially impossible observe directly objects whose gravitational fields strong light escape first considered th century john michell pierre simon laplace ref name origin ref first modern solution general relativity would characterize black hole found karl schwarzschild interpretation region space nothing escape first published david finkelstein black holes long considered mathematical curiosity theoretical work showed generic prediction general relativity discovery


neutron stars jocelyn bell burnell sparked interest gravitationally collapsed compact objects possible astrophysical reality first black hole known cygnus x identified several researchers independently black holes stellar mass form massive stars collapse end life cycle black hole formed continue grow absorbing mass surroundings absorbing stars merging black holes supermassive black holes millions solar masses may form consensus supermassive black holes


exist centers galaxies presence black hole inferred interaction matter electromagnetic radiation visible light matter falls onto black hole form external accretion disk heated friction forming quasars brightest objects universe stars passing close supermassive black hole shred streamers shine brightly swallowed ref name pmid ref stars orbiting black hole orbits used determine black hole 's mass location


observations used exclude possible alternatives neutron stars way astronomers identified numerous stellar black hole candidates binary systems established radio source known sagittarius core milky way galaxy contains supermassive black hole nbsp million solar masses february ligo scientific collaboration virgo collaboration announced first direct detection gravitational waves also represented first observation black hole merger ref name prl eleven gravitational wave events observed originated ten


merging black holes along one binary neutron star merger ref name dec ref ref name ligo list ref april first direct image black hole vicinity published following observations made event horizon telescope eht supermassive black hole messier 's galactic centre ref name apjl ref name boumanjohnson ref ref name nyt ref march eht collaboration presented first time polarized based image black hole may help better reveal forces giving rise quasars ref name nyt ref nearest known body thought black hole around light years


away see list nearest black holes though couple dozen black holes found far milky way thought hundreds millions solitary cause emission radiation would detectable gravitational lensing history simulated view black hole front large magellanic cloud note gravitational lensing effect produces two enlarged highly distorted views cloud across top milky way disk appears distorted arc idea body


massive even light could escape briefly proposed english astronomical pioneer clergyman john michell letter published november michell 's simplistic calculations assumed body might density sun concluded one would form star 's diameter exceeds sun 's factor surface escape velocity exceeds usual speed light michell referred bodies dark stars correctly noted supermassive non radiating bodies might detectable gravitational effects nearby visible bodies ref name origin ref


name thorne ref scholars time initially excited proposal giant invisible 'dark stars' might hiding plain view enthusiasm dampened wavelike nature light became apparent early nineteenth century light wave rather particle unclear influence gravity would escaping light waves ref name origin ref name thorne modern physics discredits michell 's notion light ray shooting directly surface supermassive star slowed star 's gravity stopping free falling back star 's


surface general relativity albert einstein developed theory general relativity earlier shown gravity influence light 's motion months later karl schwarzschild found solution einstein field equations describes gravitational field point mass spherical mass ref name schwarzschild translation translation ref months schwarzschild johannes droste student hendrik lorentz independently gave solution point mass wrote extensively properties solution peculiar behaviour called schwarzschild radius


leaving us outside ie nowhere ref name eddington ref subrahmanyan chandrasekhar calculated using special relativity non rotating body electron degenerate matter certain limiting mass called chandrasekhar limit stable solutions ref name venkataraman ref arguments opposed many contemporaries like eddington lev landau argued yet unknown mechanism would stop collapse partly correct white dwarf slightly massive chandrasekhar limit collapse neutron star stable robert oppenheimer others predicted neutron stars another


limit tolman oppenheimer volkoff limit would collapse reasons presented chandrasekhar concluded law physics likely intervene stop least stars collapsing black holes ref name ov ref original calculations based pauli exclusion principle gave subsequent consideration neutron neutron repulsion mediated strong force raised estimate approximately ref name bombaci ref observations neutron star merger gw thought generated black hole shortly afterward refined tov limit estimate ref name cho ref ref name margalit ref ref name shibata ref ref name ruiz ref ref name rezzolla ref oppenheimer


co authors interpreted singularity boundary schwarzschild radius indicating boundary bubble time stopped valid point view external observers infalling observers property collapsed stars called frozen stars outside observer would see surface star frozen time instant collapse takes schwarzschild radius golden age david finkelstein identified schwarzschild surface event horizon perfect unidirectional membrane causal


influences cross one direction strictly contradict oppenheimer 's results extended include point view infalling observers finkelstein 's solution extended schwarzschild solution future observers falling black hole complete extension already found martin kruskal urged publish results came beginning golden age general relativity marked general relativity black holes becoming mainstream subjects research process helped discovery pulsars jocelyn bell burnell


shown rapidly rotating neutron stars ref name araa ref time neutron stars like black holes regarded theoretical curiosities discovery pulsars showed physical relevance spurred interest types compact objects might formed gravitational collapse period general black hole solutions found roy kerr found exact solution rotating black hole two years later ezra newman found axisymmetric solution black hole rotating electrically charged work


roger penrose ref name penrose ref stephen hawking used global techniques prove singularities appear generically work penrose received half nobel prize physics hawking died based observations greenwich toronto early cygnus x galactic x ray source discovered became first astronomical object commonly accepted black hole work james bardeen jacob bekenstein carter hawking early led formulation black hole thermodynamics laws describe behaviour black hole close analogy


laws thermodynamics relating mass energy area entropy surface gravity temperature analogy completed hawking showed quantum field theory implies black holes radiate like black body temperature proportional surface gravity black hole predicting effect known hawking radiation ref name hawking etymology john michell used term dark star early th century physicists used term gravitationally collapsed object science writer marcia bartusiak traces term black hole physicist robert h dicke


early reportedly compared phenomenon black hole calcutta notorious prison people entered never left alive ref name bartusiak ref term black hole used print ''life'' ''science news'' magazines ref name bartusiak science journalist ann ewing article black holes' space dated january report meeting american association advancement science held cleveland ohio ref name scinewsewing ref december student reportedly suggested phrase black hole lecture john wheeler ref name scinewsewing


wheeler adopted term brevity advertising value quickly caught leading credit wheeler coining phrase properties structure simple illustration non spinning black hole hair theorem postulates achieves stable condition formation black hole three independent physical properties mass electric charge angular momentum black hole otherwise featureless conjecture true two black holes share values properties parameters indistinguishable one another degree conjecture


example lense thirring effect object falls black hole information shape object distribution charge evenly distributed along horizon black hole lost outside observers behavior horizon situation dissipative system closely analogous conductive stretchy membrane friction electrical resistance membrane paradigm different field theories electromagnetism friction resistivity microscopic level time reversible


black hole eventually achieves stable state three parameters way avoid losing information initial conditions gravitational electric fields black hole give little information went information lost includes every quantity cannot measured far away black hole horizon including approximately conserved quantum numbers total baryon number lepton number behavior puzzling called black hole information loss paradox gravitational time dilation around black hole physical properties


simplest static black holes mass neither electric charge angular momentum black holes often referred schwarzschild black holes karl schwarzschild discovered solution ref name schwarzschild according birkhoff 's theorem vacuum solution spherically symmetric means observable difference distance gravitational field black hole spherical object mass popular notion black hole sucking everything surroundings therefore correct near black


hole 's horizon far away external gravitational field identical body mass solutions describing general black holes also exist non rotating charged black holes described reissner nordstr metric kerr metric describes non charged rotating black hole general stationary black hole solution known kerr newman metric describes black hole charge angular momentum ref name shapiro teukolsky ref mass black hole take positive value charge angular momentum constrained mass total electric charge nbsp ''q''


simulations due relatively large strength electromagnetic force black holes forming collapse stars expected retain nearly neutral charge star rotation however expected universal feature compact astrophysical objects black hole candidate binary x ray source grs appears angular momentum near maximum allowed value uncharged limit ref name smbh math j le frac gm c math allowing definition dimensionless spin parameter ref name smbh math le frac cj gm le math ref name smbh ref '' exceed objects black holes largest value known


particle escape defining feature black hole appearance event horizon boundary spacetime matter light pass inward towards mass black hole nothing even light escape inside event horizon event horizon referred event occurs within boundary information event cannot reach outside observer making impossible determine whether event occurred predicted general relativity presence mass deforms spacetime way


paths taken particles bend towards mass event horizon black hole deformation becomes strong paths lead away black hole distant observer clocks near black hole would appear tick slowly farther away black hole due effect known gravitational time dilation object falling black hole appears slow approaches event horizon taking infinite time reach time processes object slow


viewpoint fixed outside observer causing light emitted object appear redder dimmer effect known gravitational redshift eventually falling object fades away longer seen typically process happens rapidly object disappearing view within less second hand indestructible observers falling black hole notice effects cross event horizon according clocks appear tick normally cross event horizon finite


time without noting singular behaviour classical general relativity impossible determine location event horizon local observations due einstein 's equivalence principle topology event horizon black hole equilibrium always spherical ref group note non rotating static black holes geometry event horizon precisely spherical rotating black holes event horizon oblate ref name smarr ref ref name wiltshire ref ref name delgado ref singularity center black hole described general relativity may lie gravitational singularity region spacetime curvature


becomes infinite non rotating black hole region takes shape single point rotating black hole smeared form ring singularity lies plane rotation cases singular region zero volume also shown singular region contains mass black hole solution singular region thus thought infinite density observers falling schwarzschild black hole ie non rotating charged cannot avoid carried singularity cross event


black hole different spacetime black hole acting wormhole possibility traveling another universe however theoretical since perturbation would destroy possibility also appears possible follow closed timelike curves returning one 's past around kerr singularity leads problems causality like grandfather paradox expected none peculiar effects would survive proper quantum treatment rotating charged black holes appearance singularities general relativity commonly perceived signaling breakdown


theory breakdown however expected occurs situation quantum effects describe actions due extremely high density therefore particle interactions date possible combine quantum gravitational effects single theory although exist attempts formulate theory quantum gravity generally expected theory feature singularities photon sphere photon sphere spherical boundary zero thickness photons move tangents sphere would trapped


circular orbit black hole non rotating black holes photon sphere radius times schwarzschild radius orbits would dynamically unstable hence small perturbation particle infalling matter would cause instability would grow time either setting photon outward trajectory causing escape black hole inward spiral would eventually cross event horizon ref name prd ref light still escape photon sphere light crosses photon sphere inbound trajectory captured


black hole hence light reaches outside observer photon sphere must emitted objects photon sphere event horizon ref name prd kerr black hole radius photon sphere depends spin parameter details photon orbit prograde photon rotates sense black hole spin retrograde ergosphere page fig ref rotating black holes surrounded region spacetime impossible stand still called


ergosphere result process known frame dragging general relativity predicts rotating mass tend slightly drag along spacetime immediately surrounding object near rotating mass tend start moving direction rotation rotating black hole effect strong near event horizon object would move faster speed light opposite direction stand still ergosphere black hole volume bounded black hole 's event horizon ''ergosurface''


coincides event horizon poles much greater distance around equator ref name viss objects radiation escape normally ergosphere penrose process objects emerge ergosphere energy entered extra energy taken rotational energy black hole thereby rotation black hole slows variation penrose process presence strong magnetic fields blandford znajek process considered likely mechanism enormous luminosity relativistic jets quasars


active galactic nuclei innermost stable circular orbit isco newtonian gravity test particles stably orbit arbitrary distances central object general relativity however exists innermost stable circular orbit often called isco inside infinitesimal perturbations circular orbit lead inspiral black hole location isco depends spin black hole case schwarzschild black hole spin zero math r rm isco r frac gm c math decreases increasing black hole spin particles orbiting


persuaded majority researchers field obstacle formation event horizon simulation two black holes colliding penrose demonstrated event horizon forms general relativity without quantum mechanics requires singularity form within ref name penrose shortly afterwards hawking showed many cosmological solutions describe big bang singularities without scalar fields exotic matter see penrose hawking singularity theorems kerr solution hair theorem laws black hole thermodynamics showed physical properties black holes


simple comprehensible making respectable subjects research ref name hawkingpenrose ref conventional black holes formed gravitational collapse heavy objects stars also theory formed processes ref name pacucci ref name carr primordial gravitational collapse gas cloud ripped apart black hole centre milky way observations shown blue green red respectively gravitational collapse occurs object 's internal pressure insufficient resist object 's gravity stars usually occurs either star


little fuel left maintain temperature stellar nucleosynthesis star would stable receives extra matter way raise core temperature either case star 's temperature longer high enough prevent collapsing weight ref name carroll ref collapse may stopped degeneracy pressure star 's constituents allowing condensation matter exotic denser state result one various types compact star type forms depends mass remnant


original star left outer layers blown away example type ii supernova mass remnant collapsed object survives explosion substantially less original star remnants exceeding produced stars collapse ref name carroll mass remnant exceeds tolman oppenheimer volkoff limit ref name ov either original star heavy remnant collected additional mass accretion matter even degeneracy pressure neutrons insufficient stop


collapse known mechanism except possibly quark degeneracy pressure see quark star powerful enough stop implosion object inevitably collapse form black hole ref name carroll archive date may ref gravitational collapse heavy stars assumed responsible formation stellar mass black holes star formation early universe may resulted massive stars upon collapse would produced black holes black holes could seeds supermassive black holes found centers galaxies ref name reesvolonteri ref


suggested massive black holes typical masses could formed direct collapse gas clouds young universe ref name pacucci ref massive objects proposed seeds eventually formed earliest quasars observed already redshift math z sim math candidates objects found observations young universe ref name pacucci energy released gravitational collapse emitted quickly outside observer actually see end process even though collapse takes finite amount


time reference frame infalling matter distant observer would see infalling material slow halt event horizon due gravitational time dilation light collapsing material takes longer longer reach observer light emitted event horizon forms delayed infinite amount time thus external observer never sees formation event horizon instead collapsing material seems become dimmer increasingly red shifted eventually fading away primordial black holes big bang gravitational collapse requires great density


current epoch universe high densities found stars early universe shortly big bang densities much greater possibly allowing creation black holes high density alone enough allow black hole formation since uniform mass distribution allow mass bunch order primordial black holes formed dense medium must initial density perturbations could grow gravity different models early universe vary widely predictions


scale fluctuations various models predict creation primordial black holes ranging size planck mass ''m'' hundreds thousands solar masses ref name carr primordial ref despite early universe extremely dense far denser usually required form black hole collapse black hole big bang models gravitational collapse objects relatively constant size stars necessarily apply way rapidly expanding space big bang high energy collisions simulated


event cms detector collision micro black hole may created gravitational collapse process could create black holes principle black holes could formed high energy collisions achieve sufficient density events detected either directly indirectly deficiency mass balance particle accelerator experiments suggests must lower limit mass black holes theoretically boundary expected lie around planck mass quantum effects expected invalidate


predictions general relativity would put creation black holes firmly reach high energy process occurring near earth however certain developments quantum gravity suggest minimum black hole mass could much lower braneworld scenarios example put boundary low would make conceivable micro black holes created high energy collisions occur cosmic rays hit earth 's atmosphere possibly large hadron collider cern theories speculative creation black holes


processes deemed unlikely many specialists ref name lhcsafety ref even micro black holes could formed expected would evaporate seconds posing threat earth growth black hole formed continue grow absorbing additional matter black hole continually absorb gas interstellar dust surroundings growth process one possible way supermassive black holes may formed although formation supermassive black holes still open field research ref name reesvolonteri


similar process suggested formation intermediate mass black holes found globular clusters black holes also merge objects stars even black holes thought important especially early growth supermassive black holes could formed aggregation many smaller objects ref name reesvolonteri process also proposed origin intermediate mass black holes evaporation hawking predicted black holes entirely black emit small amounts thermal radiation temperature ''c'' ''gm''b ref


name hawking ref effect become known hawking radiation applying quantum field theory static black hole background determined black hole emit particles display perfect black body spectrum since hawking 's publication many others verified result various approaches hawking 's theory black hole radiation correct black holes expected shrink evaporate time lose mass emission photons particles ref name hawking temperature thermal spectrum hawking temperature proportional surface gravity black hole


schwarzschild black hole inversely proportional mass hence large black holes emit less radiation small black holes stellar black hole hawking temperature nbsp nanokelvins far less nbsp k temperature cosmic microwave background radiation stellar mass larger black holes receive mass cosmic microwave background emit hawking radiation thus grow instead shrinking hawking temperature larger nbsp k able evaporate black hole would need mass less moon


small black hole quantum gravity effects expected play important role could hypothetically make small black hole stable although current developments quantum gravity indicate case hawking radiation astrophysical black hole predicted weak would thus exceedingly difficult detect earth possible exception however burst gamma rays emitted last stage evaporation primordial black holes searches flashes proven unsuccessful provide stringent limits possibility existence low


galaxies even would evaporate timescale years ref name frautschi see page table section black hole decay previous sentence page ref observational evidence nature black holes emit electromagnetic radiation hypothetical hawking radiation astrophysicists searching black holes must generally rely indirect observations example black hole 's existence sometimes inferred observing gravitational influence upon surroundings april image released black hole seen magnified fashion


immediate environment event horizon black holes black hole centre milky way april eht began observation black hole center messier ref name eht ref eight radio observatories six mountains four continents observed galaxy virgo days april provide data yielding image two years later april ref name overbyeapril ref two years data processing eht released first direct image black hole specifically supermassive black hole


lies center aforementioned galaxy visible black hole shows black loss light within dark region rather gases edge event horizon displayed orange red define black hole ref name grossmanapril ref brightening material 'bottom' half processed eht image thought caused doppler beaming whereby material approaching viewer relativistic speeds perceived brighter material moving away case black


hole phenomenon implies visible material rotating relativistic speeds nbsp km speeds possible centrifugally balance immense gravitational attraction singularity thereby remain orbit event horizon configuration bright material implies eht observed perspective catching black hole 's accretion disc nearly edge whole system rotated clockwise however extreme gravitational lensing associated black holes produces illusion perspective sees accretion disc reality ring eht


studies black holes predicted appearance non rotating black hole toroidal ring ionised matter proposed model sagittarius asymmetry due doppler effect resulting enormous orbital speed needed centrifugal balance strong gravitational attraction hole detection gravitational waves merging black holes september ligo gravitational wave observatory made first ever successful direct observation gravitational waves ref name prl ref ref name nyt db ref signal consistent theoretical predictions gravitational waves produced merger


two black holes one solar masses around solar masses ref name prl ref name properties ref observation provides concrete evidence existence black holes date instance gravitational wave signal suggests separation two objects prior merger nbsp km roughly four times schwarzschild radius corresponding inferred masses objects must therefore extremely compact leaving black holes plausible interpretation ref name prl importantly signal observed ligo also included start post merger ringdown


signal produced newly formed compact object settles stationary state arguably ringdown direct way observing black hole ref name cardoso ref ligo signal possible extract frequency damping time dominant mode ringdown possible infer mass angular momentum final object match independent predictions numerical simulations merger ref name tests ref frequency decay time dominant mode determined geometry photon sphere hence observation mode


confirms presence photon sphere however cannot exclude possible exotic alternatives black holes compact enough photon sphere ref name cardoso observation also provides first observational evidence existence stellar mass black hole binaries furthermore first observational evidence stellar mass black holes weighing solar masses ref name implications ref since many gravitational wave events observed ref name ligo list proper motions stars orbiting sagittarius proper motions stars near center milky way provide strong observational


evidence stars orbiting supermassive black hole ref name gillessen ref since astronomers tracked motions stars orbiting invisible object coincident radio source sagittarius fitting motions keplerian orbits astronomers able infer object must contained volume radius light years cause motions stars ref name ghez ref since one stars called completed full orbit orbital data astronomers able refine calculations mass


radius less light years object causing orbital motion stars ref name gillessen upper limit object 's size still large test whether smaller schwarzschild radius nevertheless observations strongly suggest central object supermassive black hole plausible scenarios confining much invisible mass small volume ref name ghez additionally observational evidence object might possess event horizon feature unique black holes accretion matter website nasa access date


august url status dead archive url https webarchiveorg web http wwwjplnasagov news newsphprelease archive date august ref due conservation angular momentum gas falling gravitational well created massive object typically form disk like structure around object artists' impressions accompanying representation black hole corona commonly depict black hole flat space body hiding part disk behind reality gravitational lensing would greatly distort image accretion disk nasa simulated view outside horizon schwarzschild black hole lit thin accretion disk


within disk friction would cause angular momentum transported outward allowing matter fall farther inward thus releasing potential energy increasing temperature gas ref name mcclintockremillard section ref blurring x rays near black hole nustar august ref name nasa accreting object neutron star black hole gas inner accretion disk orbits high speeds proximity compact object resulting friction significant heats inner disk temperatures emits vast amounts electromagnetic radiation


mainly x rays bright x ray sources may detected telescopes process accretion one efficient energy producing processes known rest mass accreted material emitted radiation ref name mcclintockremillard nuclear fusion rest mass emitted energy many cases accretion disks accompanied relativistic jets emitted along poles carry away much energy mechanism creation jets currently well understood part due insufficient data


many universe 's energetic phenomena attributed accretion matter black holes particular active galactic nuclei quasars believed accretion disks supermassive black holes ref name cms similarly x ray binaries generally accepted binary star systems one two stars compact object accreting matter companion ref name cms also suggested ultraluminous x ray sources may accretion disks intermediate mass black holes november first direct observation quasar accretion disk around


supermassive black hole reported x ray binaries computer simulation star consumed black hole blue dot indicates location black hole animation compares x ray heartbeats grs igr j two black holes ingest gas companion stars chandra x ray observatory image cygnus x first strong black hole candidate discovered x ray binaries binary star systems emit majority radiation x ray part spectrum x ray emissions generally thought result one


stars compact object accretes matter another regular star presence ordinary star system provides opportunity studying central object determine might black hole ref name cms system emits signals directly traced back compact object cannot black hole absence signal however exclude possibility compact object neutron star studying companion star often possible obtain orbital parameters system


obtain estimate mass compact object much larger tolman oppenheimer volkoff limit maximum mass star without collapsing object cannot neutron star generally expected black hole ref name cms ref first strong candidate black hole cygnus x discovered way charles thomas bolton louise webster paul murdin doubt however remained due uncertainties result companion star much heavier candidate black hole currently better candidates black


holes found class x ray binaries called soft x ray transients class system companion star relatively low mass allowing accurate estimates black hole mass moreover systems actively emit x rays several months every years period low x ray emission called quiescence accretion disk extremely faint allowing detailed observation companion star period one best candidates v cygni ref name cms quasi periodic oscillations x ray emissions accretion disks sometimes flicker certain


shown activity active galactic nuclei agn may explained presence supermassive black holes millions times massive stellar ones models agn consist central black hole may millions billions times massive sun disk interstellar gas dust called accretion disk two jets perpendicular accretion disk ref name krolik ref ref name sparkegallagher ref detection unusually bright x ray flare sagittarius black hole center milky way galaxy january ref


correlation mass hole velocity dispersion host galaxy 's bulge known sigma relation strongly suggests connection formation black hole galaxy ref name msigma ref archive date february ref microlensing proposed another way black hole nature object may tested future observation effects caused strong gravitational field vicinity one effect gravitational lensing deformation spacetime around massive object causes light rays deflected much light passing


optic lens observations made weak gravitational lensing light rays deflected arcseconds however never directly observed black hole ref name bozza one possibility observing gravitational lensing black hole would observe stars orbit around black hole several candidates observation orbit around sagittarius ref name bozza ref alternatives evidence stellar black holes strongly relies existence upper limit mass neutron star size limit


object maximum mass ref name cms since average density black hole inside schwarzschild radius inversely proportional square mass supermassive black holes much less dense stellar black holes average density black hole comparable water ref name cms consequently physics matter forming supermassive black hole much better understood possible alternative explanations supermassive black hole observations much mundane example supermassive black hole could modelled large cluster


dark objects however alternatives typically stable enough explain supermassive black hole candidates ref name cms evidence existence stellar supermassive black holes implies order black holes form general relativity must fail theory gravity perhaps due onset quantum mechanical corrections much anticipated feature theory quantum gravity feature singularities event horizons thus black holes would real artifacts example fuzzball model based string theory


individual states black hole solution generally event horizon singularity classical semi classical observer statistical average states appears ordinary black hole deduced general relativity theoretical objects conjectured match observations astronomical black hole candidates identically near identically function via different mechanism include gravastar black star dark energy star open questions entropy thermodynamics ''k'' ''g '' ''a'' caption formula bekenstein hawking entropy black hole depends


area black hole constants speed light boltzmann constant newton 's constant reduced planck constant planck units reduces width hawking showed general conditions ref group note particular assumed matter satisfies weak energy condition ref total area event horizons collection classical black holes never decrease even collide merge result known second law black hole mechanics remarkably similar second law thermodynamics


theory predicts black hole radiates blackbody radiation constant temperature seemingly causes violation second law black hole mechanics since radiation carry away energy black hole causing shrink radiation however also carries away entropy proven general assumptions sum entropy matter surrounding black hole one quarter area horizon measured planck units fact always increasing allows formulation first law black hole mechanics


analogue first law thermodynamics mass acting energy surface gravity temperature area entropy ref name wald one puzzling feature entropy black hole scales area rather volume since entropy normally extensive quantity scales linearly volume system odd property led gerard 't hooft leonard susskind propose holographic principle suggests anything happens volume spacetime described data boundary volume


although general relativity used perform semi classical calculation black hole entropy situation theoretically unsatisfying statistical mechanics entropy understood counting number microscopic configurations system macroscopic qualities mass charge pressure etc without satisfactory theory quantum gravity one cannot perform computation black holes progress made various approaches quantum gravity andrew strominger cumrun vafa showed counting microstates specific supersymmetric black hole string theory reproduced bekenstein hawking entropy


since similar results reported different black holes string theory approaches quantum gravity like loop quantum gravity information loss paradox black hole internal parameters information matter went forming black hole lost regardless type matter goes black hole appears information concerning total mass charge angular momentum conserved long black holes thought persist forever information loss


problematic information thought existing inside black hole inaccessible outside represented event horizon accordance holographic principle however black holes slowly evaporate emitting hawking radiation radiation appear carry additional information matter formed black hole meaning information appears gone forever ref name playdice ref question whether information truly lost black holes black hole information paradox divided theoretical physics community see thorne hawking preskill bet quantum mechanics loss information corresponds


single emission hawking radiation involves two mutually entangled particles outgoing particle escapes emitted quantum hawking radiation infalling particle swallowed black hole assume black hole formed finite time past fully evaporate away finite time future emit finite amount information encoded within hawking radiation according research physicists like page leonard susskind eventually time outgoing particle must entangled hawking radiation


black hole previously emitted seemingly creates paradox principle called monogamy entanglement requires like quantum system outgoing particle cannot fully entangled two systems time yet outgoing particle appears entangled infalling particle independently past hawking radiation order resolve contradiction physicists may eventually forced give one three time tested principles einstein 's equivalence principle unitarity local quantum field theory one possible solution violates equivalence principle firewall destroys incoming


particles event horizon general assumptions abandoned remains topic debate ref name unruh ref see also binary black hole black box black brane black string black hole initiative black hole starship black holes fiction blanet btz black hole direct collapse black hole gravitational singularity hypothetical black hole disambiguation kugelblitz astrophysics list black holes list nearest black holes outline black holes sonic black hole susskind hawking battle timeline black hole physics white hole notes references reading popular reading university textbooks


monographs lecture notes book based available free sean carroll 's https wwwpreposterousuniversecom spacetimeandgeometry website review papers lecture notes slac summer institute external links ''stanford encyclopedia philosophy'' http platostanfordedu entries spacetime singularities singularities black holes erik curiel peter bokulich http hubblesiteorg explore astronomy black holes black holes gravity 's relentless pull interactive multimedia web site physics astronomy black holes space telescope science institute esa 's https wwwesaint gsp act phy projects blackholes webglhtml black hole visualization http apodnasagov htmltest gifcity bh pub faqhtml frequently asked questions faqs black holes https webarchiveorg web http casacoloradoedu ajsh schwphtml schwarzschild geometry http hubblesiteorg explore astronomy black holes homehtml hubble site https wwwnytimescom science black holes astrophysics nameshtml black holes basic nyt april


videos http wwwesoorg public videos eso b year long study tracks stars orbiting milky way black hole https webarchiveorg web http wwwmpempgde ir gc indexphp movie black hole candidate max planck institute https wwwbbccom news science environment computer visualisation signal detected ligo https wwwyoutubecom watchv dwbcu two black holes merge one based upon signal gw galaxies theory relativity concepts astronomy articles containing video clips


infixing distal femoral traction pin preopt fractured femur medicine '''traumatology''' greek ''trauma'' meaning injury wound study wounds injuries caused accidents violence person surgical therapy repair damage traumatology branch medicine often considered subset surgery countries without specialty trauma surgery often sub specialty orthopedic surgery traumatology may also known ''accident surgery'' branches branches traumatology include medical traumatology psychological traumatology medical traumatology

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Surgery
Traumatology


defined study specializing treatment wounds injuries caused violence general accidents type traumatology focuses surgical procedures future physical therapy patients need repair damage recover properly psychological traumatology type damage one 's mind due distressing event type trauma also result overwhelming amounts stress one 's life psychological trauma usually involves type physical trauma poses threat one 's sense security survival psychological trauma often leaves people


feeling overwhelmed anxious threatened ref name emotional psychological trauma emotional psychological trauma learning heal recent childhood trauma move life nd http wwwhelpguideorg articles ptsd trauma emotional psychological traumahtm ref trauma also classified acute results single stressful dangerous situation chronic results repeated prolonged exposure highly stressful situations complex results exposure multiple traumatic events secondary vicarious trauma another form trauma person develops trauma symptoms close contact someone experienced traumatic event types trauma comes types


trauma medical psychological traumatology go hand hand types trauma include car accidents gunshot wounds concussions ptsd incidents etc medical traumas repaired surgeries however still cause psychological trauma stress factors example teenager car accident broke wrist needed extensive surgery save arm may experience anxiety driving car post accident ptsd diagnosed person experiences one intense traumatic events react fear complaints three categorical symptoms lasting one month longer


categories experiencing traumatic event avoiding anything associated trauma increased symptoms increased psychological arousal guidelines essential trauma care airway management monitoring management injuries key guidelines comes medical trauma care airway management key component emergency scene care using systematic approach first responders must access patient 's airway blocked order ensure patient gets enough circulation remain calm ref name mock mock c guidelines essential trauma care geneva world health organization ref monitoring patients making sure


body go shock another essential guideline comes medical trauma care nurses required watch patients check blood pressure heart rate etc make sure patients well crashing comes managing injuries head neck injuries require care post surgery head injuries one major causes trauma related death disabilities worldwide important patients head trauma get ct scans post surgery insure problems ref name mock guidelines psychological


trauma care range approaches assist victims overcome anxiety stress follows psychological trauma affected persons also follow self care exercise socializing familiar safe associates family members trauma disturbs body 's natural equilibrium putting state fear hyper arousal ref name emotional psychological trauma exercising thirty minutes day facilitated nervous system unfreeze traumatic state surrounded good support system powerful factor treating psychological trauma participating social activities volunteering making new friends


ways help forget cope traumatic events coming terms childhood trauma especially challenging patient assessment advanced trauma life support training medical doctors dealing trauma revised trauma score injury severity score abbreviated injury scale triage wound assessment factors assessment wounds nature wound whether laceration abrasion bruise burn size wound length width depth extent overall area tissue damage caused impact mechanical force reaction chemical agents


example fires exposure caustic substances forensic physicians well pathologists may also required examine traumatic wounds people see also ''journal injury violence research'' major trauma polytrauma trauma surgery ''traumatology'' journal references external links http wwweastorg eastern association surgery trauma http wwwefortorg european federation national associations orthopaedics traumatology http wwwjivresearchorg journal injury violence research http wwwtraumaorg traumaorg trauma resources medical professionals surgical specialties


hubble space telescope earth sts mission '''astronautics''' '''cosmonautics''' theory practice travel beyond earth 's atmosphere outer space spaceflight one main applications space science overarching field term ''astronautics'' originally ''astronautique'' french coined j h rosny president goncourt academy analogy aeronautics degree technical overlap two fields term aerospace often used describe robert esnault pelterie published first book new research field

Applied science
Engineering and technology
Mechanical Engineering
Aerospace engineering
Astronautics


term ''cosmonautics'' originally ''cosmonautique'' french introduced ary sternfeld book ''initiation la cosmonautique'' introduction cosmonautics book brought prix rep hirsch later known prix d'astronautique french astronomical society aeronautics restrictions mass temperatures external forces require applications space survive extreme conditions high grade vacuum radiation bombardment interplanetary space magnetic belts low earth orbit space launch vehicles must withstand titanic forces satellites experience huge variations temperature brief periods ref name sellers ''understanding space


introduction astronautics'' sellers nd ed mcgraw hill ref extreme constraints mass cause astronautical engineers face constant need save mass design order maximize actual payload reaches orbit history early history astronautics theoretical fundamental mathematics space travel established isaac newton treatise ''philosophi naturalis principia mathematica'' ref name bmw ''fundamentals astrodynamics'' bate mueller white dover new york ref mathematicians swiss leonhard euler franco italian joseph louis lagrange also made essential contributions th th centuries spite


astronautics become practical discipline mid th century hand question spaceflight puzzled literary imaginations figures jules verne h g wells beginning th century russian cosmist konstantin tsiolkovsky derived rocket equation governing equation rocket based propulsion enabling computation final velocity rocket mass spacecraft math math combined mass propellant spacecraft math math exhaust velocity propellant math v e math math delta v v e ln frac math early robert h goddard


developing liquid propellant rockets would brief decades become critical component designs famous rockets v saturn v prix d'astronautique astronautics prize awarded soci astronomique de france french astronomical society first prize subject international award established aviation astronautical pioneer robert esnault pelterie andr louis hirsch given recognition study interplanetary travel astronautics mid space race ussr us begun subdisciplines although many regard astronautics


rather specialized subject engineers scientists working area must knowledgeable many distinct fields astrodynamics study orbital motion specializing field examine topics spacecraft trajectories ballistics celestial mechanics spacecraft propulsion spacecraft change orbits launched spacecraft variety rocket engine thus research efforts focus variety rocket propulsion chemical nuclear electric spacecraft design specialized form systems engineering centers combining necessary subsystems particular launch vehicle satellite controls


keeping satellite rocket desired orbit spacecraft navigation orientation attitude control space environment although sub discipline physics rather astronautics effects space weather environmental issues constitute increasingly important field study spacecraft designers bioastronautics related fields study aeronautics aerospace mechanical engineering physics see also atmospheric reentry frank malina french space program hermann oberth sergei korolev wernher von braun references reading vehicle operation


'''morale''' also known '''esprit de corps''' capacity group 's members maintain belief institution goal particularly face opposition hardship morale often referenced authority figures generic value judgment willpower obedience self discipline group tasked performing duties assigned superior according alexander h leighton morale capacity group people pull together persistently consistently pursuit common purpose morale important military improves unit cohesion without good

Applied science
Military sciences
Tactics
Morale


morale force likely give surrender morale usually assessed collective rather individual level wartime civilian morale also important esprit de corps considered important part fighting unit definition military history experts agreed precise definition morale clausewitz 's comments subject described deliberately vague modern scholars george francis robert henderson widely read military author pre world war era viewed morale related instinct self preservation suppression


said moral fear turning back words willingness fight bolstered strong sense duty henderson wrote ref name executions ref blockquote human nature must basis every leader 's calculations sustain ''moral e '' men break ''moral e '' enemy great objects ambitious success must always keep view blockquote proceedings southborough committee inquiry concerning shellshock testimony colonel j f c fuller defined morale acquired quality highly trained troops counterbalances


influence instinct self preservation henderson 's moral fear soldier 's sense duty contrasted fear death control one 's troops required commander authoritarian force strategies deployed purpose ref name executions esprit de corps means ' 'spirit body'' french phrase military ref military science two meanings morale primarily means unit cohesion cohesion unit task force military group morale often highly dependent soldier effectiveness health comfort safety belief purpose therefore


army good supply lines sound air cover clear objective typically possess whole better morale one without historically elite military units special operations forces high morale due training pride unit unit 's morale said depleted means close crack surrender well worth noting generally speaking commanders look morale specific individuals rather fighting spirit squadrons divisions battalions ships etc ref august article entitled army


morale declines survey states quarter us army 's officers enlisted soldiers believe nation 's largest military branch headed right direction common reasons cited bleak outlook ineffective leaders senior levels fear losing best brightest decade war perception especially among senior enlisted soldiers army soft lacks sufficient discipline employee morale employee morale proven direct effect productivity one corner stones business see


also collective identity demoralization warfare information warfare motivation pre work assembly psychological warfare rank theory depression references external links matteo ermacora https encyclopedia onlinenet article civilian morale civilian morale https encyclopedia onlinenet homehtml online international encyclopedia first world war psychological warfare psychological attitude motivation group processes


secular usage '' 'religious education''' teaching particular religion although united kingdom term ' 'religious instruction'' would refer teaching particular religion ' 'religious education'' referring teaching religions general varied aspects beliefs doctrines rituals customs rites personal roles western secular culture religious education implies type education largely separate academia generally regards religious belief fundamental tenet operating modality well prerequisite attendance secular concept substantially different societies

Applied science
Divinity
Field ministry
Religious education


adhere religious law wherein religious education connotes dominant academic study typically religious terms teaches doctrines define social customs laws violations thereof crimes else misdemeanors requiring punitive correction free choice religious education parents according conviction protected convention discrimination education religious education controversial worldwide countries united states publicly fund religious education make part compulsory schooling contexts united kingdom 'open' religious education emerged christian confessionalism


intended promote religious literacy without imparting particular religious perspective kind religious education drawn criticism argued neutral perspective study religions kind compulsory schooling likely impact formation student 's religious identity overview since people within given country often hold varying religious non religious beliefs government sponsored religious education source conflict countries vary widely whether religious education allowed government run schools often called public schools allow also vary


type education provided people oppose religious education public schools various grounds one constitutes state sponsorship establishment whatever religious beliefs taught others argue particular religion taught school children belong religion either feel pressure conform excluded peers proponents argue religious beliefs historically socialized people 's behavior morality feel teaching religion school important encourage children responsible spiritually sound adults religious education religion christianity


christianity catechesis refers religious instruction children adult converts church educational system church jesus christ latter day saints lds church provides religious education youth adults countries islam traditional muslim education children taught read sometimes speak arabic memorize major suras qur'an many countries state run schools purpose known madrasah islamiyyah arabic meaning islamic school traditionally settlement may pay mullah teach children historic tradition sufi mullahs


society understanding natural history literature requires sense historical jewish sensibility approaches various regions new zealand new zealand religious education refers academic teaching religious studies religious instruction refers religious faith teaching occurs private religious schools integrated religious state schools sometimes within secular nz state primary schools directed individual schools' board trustees around nz state primary schools carried religious instruction classes officially recognised syllabuses school officially closed


order allow classes go ahead organised groups secular education network nz association rationalists humanists actively lobbying government legislation changed remove classes state primary schools china people 's republic china formal religious education permitted religious education usually occurs scheduled sessions private homes religious teachers usually move weekly monthly circuit staying guests private houses exchange teaching india india number private schools run religious institutions especially


instructional programs scriptural texts standardized iskcon ministry educational development gbc committee vaisnava training education categorized level difficulty india primarily provided mayapur institute higher education training vrindavan institute higher education iskcon also offers instruction archana murti worship devotional ceremony mayapur academy ref name mayapurschool addition regular formal education number religious institutions instituted regular informal religious spiritual education programs children adults japan japan many christian schools universities mandatory


compulsory learn government tries hire teachers kind convincing order teach religious content step step students religions taught public schools private schools recognized minority groups religions zoroastrianism christianity judaism schools supervised ministry education imposes certain curriculum requirements directors private schools must muslim exceptions europe austria austria 's history multinational empire included largely


islamic bosnia sunni islam taught side side roman catholic protestant orthodox classes since th century however children belonging minority religions judaism buddhism latter day saint movement also study religious education various denominations many schools secular classes ethics attended alternatively finland finland religious education mandatory subject comprehensive schools years senior upper secondary schools years finnish students study evangelical lutheran religious education student receive religious education according


religion denomination registered finland since religious education compulsory subject pupils belong religious group taught ethics also non lutheran pupils participate evangelical lutheran religious education france france state recognizes religion fund religious education however state subsidizes private teaching establishments including religious ones strict conditions forcing religion courses students discriminating students according religion exception area alsace moselle historical reasons ruled germany system


instituted rest france specific local law state supports public education religions catholic protestant jewish mostly accord german model germany eschatology used curriculum german religious education historically various confessions germany contributed primary secondary education still education germany still embodies legacy prussian education system introduced frederick great curricula various states germany since included basic technical skills also music singing religious christian education


close cooperation churches led churches assigned specific status legal entity public law k rperschaft des ffentlichen rechts germany legacy weimar compromise still force today federal states germany long history almost even division roman catholicism protestantism arrangement whereby religious bodies oversee training mainline protestant catholic jewish religious education teachers one federal states includes orthodox christian teachers well berlin bremen see bremen


clause brandenburg religious education mandatory eg bremen state authorized bible studies offered supervised specific confession training supposed conducted according modern standards humanities teachers trained mostly state run colleges universities teachers teach religion public schools paid state bound german constitution well answerable churches content teaching children part mainstream religion applies eg jehovah 's witnesses members new apostolic


church still take part classes one confessions want opt attend classes ethics philosophy instead humanistischer verband deutschlands atheist agnostic association adopted legal setup churches allowed offer classes age children may decide want attend religion classes willing attend younger children decision parents state also subsidizes religious


waldorf education schools paying expenses schools follow curricula public schools federal state though introduction islamic religious education germany faced various burdens thresholds introduced currently around three million muslims mostly turkish origin country see islam germany many members legal entity states could arrange matters unlike christian churches' representatives humanists first time german


history state hessen acknowledged muslim community reform oriented ahmadiyya ''k rperschaft des ffentlichen rechts'' germany deemed historical milestone ref name welt ahmadiyya applied status able offer religious education state schools allowed maintain cemeteries members' fees collected state 's church tax system ref name welt https wwwweltde politik deutschland article der islam gehoert nun offiziell zu deutschlandhtml der islam geh rt nun offiziell zu deutschland islam part germany quoting famous speech president christian wulff freia peters ''die welt'' ref greece greece students


public primary secondary schools typically ages learn basics greek orthodox faith using official curriculum accordance eu 's religious freedom rules parents opt religious classes requesting paper without additional justification students age opt students opt attend alternative non religious courses universities mostly public n't religious content unless 's related studies italy italy catholic religious education curricula subject students attending primary secondary school ages


though students opt religious classes attend alternative courses instead ref name giorda ref alternatively religious class takes place first last hour non attending students enter late school go early consists optional hour week primary secondary school curriculum data shows percentage students choose attend religious class steady decline percentage religious education first introduced mandatory activity italy fascist regime following lateran treaty became


optional law n instituted possibility national public recruiting religion professors enrolled within italian primary secondary schools teachers become public servants waged directly minister public education removable working place specific norm enforced right enrolled religion professors destinated different teaching matters compatible academic degrees denied needy diocesan license effect personal request job transfer admitted public recruiting selection


teachers need specific teaching license released diocesan bishop held first national public recruiting selection type another forecasted december agreement signed cardinal gualtiero bassetti italian minister public education lucia azzolina february italian minister marco bussetti cardinal giuseppe versaldi prefect congregation catholic education signed agreement mutual recognition academic qualifications issued universities holy see italy agreement increased significantly number degree titles recognized


religion belief ref name onderwijsnl ref public primary schools strongly represented followed roman catholic schools protestant christian primary schools primary schools denomination category 'other special' relationship schools different denominations remained stable recent years government pays types education schools must meet conditions example education must sufficient quality also requirements example minimum number pupils competence teachers number hours education ref name onderwijsnl poland


first drafted preserved subsequent legal reforms constitutional changes due secular revolution previous practices ottoman education system abandoned newer unity education law interpreted totally excluding religious instruction public schools newly established republic turkey aimed secular western rule atat rk changes acceptance latin alphabet taught pupils national schools gregorian calendar took place new established country closure madrasas ref name journalibsueduge ref


provided society religious knowledge education classes religion also abolished schools religious education quran courses religious activities controlled government separated regular education ref name journalibsueduge situation changed one party period came end faculty divinity introduced ankara university educate raise train imams carry scientific research religion mostly islam ref name journalibsueduge result multiparty democracy new government led former democratic


party established government introduced religion course secondary schools democrat party religion started show lecture schools name culture religion knowledge ethics parents give permission furthermore imam hatip schools established cities turkey limited number students following years coup number imam hatip schools religious education increased turkey ref name journalibsueduge military coup religious education school transformed became


compulsory part curriculum culture religion knowledge ethics course content religious education prepared state ensured children first exposed accepted interpretations islam exposed religious teachings late right students graduated imam hatip schools limited education reform bill moreover middle school imam hatip schools converted regular high schools students continue higher education fields rather theology dignity faculties wish


besides beginning 's new law led decrease number quran courses law introduce students attend quran courses finished eight year education rather five ref name journalibsueduge united kingdom united kingdom catholic church england england jewish schools long supported within state system state funded schools duty provide compulsory religious education introduction national curriculum religious education compulsory subject state schools state school religious education


non proselytising covers variety faiths although legislation requires include christian content faiths church scotland schools although often presence scottish non denominational institutions national curriculum religious education state schools england england wales content syllabus state schools agreed local education authorities leas ratification standing advisory council religious education sacre comprising members different religious groups teachers local councillors parents children state schools


withdraw part lessons religious sex relationship education want small scale research suggests religious education may unpopular students minority religious backgrounds distorts misrepresents religious traditions adherents academics noted become overburdened expectations uk including acquiring developing knowledge understanding christianity principal religions developing ability make reasoned informed judgements religious moral issues enhancing pupils' spiritual moral cultural social development developing positive attitudes towards others


university birmingham project examined personal perspectives professional beliefs teachers england project article three dominant moral assumptions teachers identified historical literature moral assumptions explained using metaphor rhizome appear regular intervals time education act present day first universalist assumption universal truths behind major world 's religions study religion identify present pupils


second vicarious assumption idea teaching religion one build pupils world views also therefore moral belief structures final instrumentalist assumption posits studying religion pupils instrumentally become moral time four major findings final report project based interviews survey respondents firstly personal world views found inform teachers vision subject underpinning motivation teach subject historically debate whether teachers strive


manner teachers faith non faith schools approach virtue knowledge understanding also identified north america canada canada religious education varying status one hand publicly funded organized separate schools roman catholics protestants mandated provinces circumstances various sections constitution act hand growing level multiculturalism particularly ontario debate emerged whether publicly funded religious education one group permissible example newfoundland withdrew funding protestant roman catholic schools


constitutional amendment quebec abolished religious education funded state ''education act '' took effect july year constitutional amendment quebec organized schools along linguistic rather religious lines ontario however move abolish funding strongly resisted provincial election topic funding faith based schools catholic became major topic provincial conservative party defeated due part support idea united states united states religious education often provided voluntary


supplementary sunday school hebrew school catechism classes taught children families' places worship either conjunction worship services time week weekday school classes families believe supplementary religious education inadequate send children private religious schools called parochial schools catholic day schools yeshivas jewish many faiths also offer private college graduate level religious schools seminaries accredited colleges us law religious education forbidden public schools except neutral academic perspective however


minority communities released time granted week make religious education convenient without violating separation church state teacher school administration endorse one religion considered infringement establishment clause first amendment boundaries rule frequently tested court cases challenging treatment eastern religion meditation programs students traditional religious holidays displays religious articles documents ten commandments recitation pledge allegiance since described us one nation god


whether prayer accommodated classroom see also character education christian views classics freedom education islamic studies jewish day school parochial school private school religion children religious school religious studies state religion tripi aka references reading https wwwchurchofjesuschristorg study ensign news church four seventies releasedlang eng four seventies released ''ensign'' november http wwwaasianstorg absts abst china c htm association asian studies session chinese lay buddhists early twentieth century question secularization four case studies association asian studies inc mar web sept http webarchivenationalarchivesgovuk http wwwgovernornetcouk linkattachments faith systempdf faith system crown copyright web sept http wwwedgov policy gen guid religionandschools prayer guidancehtml department


education overview governing constitutional principles sept web sept http cohss paper pdf cultural study religious education america feng chia journal humanities social sciences pp nbsp jun author grace hui chin lin external links


'''online business''' '''e business''' kind business commercial transaction includes sharing information across internet commerce constitutes exchange products services businesses groups individuals seen one essential activities business electronic commerce focuses use information communication technology enable external activities relationships business individuals groups businesses e business refers business help internet electronic business differs electronic commerce deal online transactions selling


buying product service also enables conduct business processes inbound outbound logistics manufacturing operations marketing sales customer service within value chain internal external networks term e business coined ibm 's marketing internet team market participants electronic business electronic business take place large number market participants business consumer private individuals public administrations organizations ngos various market participants divided three main groups business b consumer c


administration either buyers service providers within market nine possible combinations electronic business relationships b c b b belong e commerce b belong e government sector also part electronic business supply chain management e business development e commerce industry business activities becoming complex coordinate efficiency business crucial success e commerce hence well developed supply chain management key component e commerce e commerce industry


focusing building appropriate web site also focuses suitable infrastructure well developed supply chain strategy etc definition supply chain management refers management flow goods services activities connected transforming raw materials final products goal business maximize customer value gain competitive advantage others supply chain management e commerce industry mainly focuses manufacturing supplying raw materials managing supply demand distribution etc effective supply chain management e commerce often gives advantage


companies positively leverage new opportunities maximizing profit satisfying meeting customer 's expectations well developed supply chain management company chance better success forming right partnership supply network automating business etc enabling role e business technologies supply chain organizations development intra inter organizational collaboration impact performance discussed depth article nada sanders sum effective supply chain management e commerce industry needed three main reasons ensuring high service levels stock


availability encouraging positive customer experience reviews building brand reputation cost efficiency history one founding pillars electronic business development electronic data interchange edi electronic data interchange system replaced traditional mailing faxing documents digital transfer data one computer another without human intervention michael aldrich considered developer predecessor online shopping entrepreneur connected television set transaction processing computer telephone line called teleshopping meaning shopping distance


loosely interchangeable become part common vernacular according us department commerce estimated retail e commerce sales q representing almost total us retail sales q business model transformation toward e business complex order succeed need balance strategy adapted business model e intermediary marketplaces right processes sales marketing technology supply chain management customer relationship management organizations go online decide e business models best suit goals


business model defined organization product service information flows source revenues benefits suppliers customers concept e business model used online presence revenue model key component business model revenue model profit model framework generating revenues identifies revenue source pursue value offer price value pays value key component company 's business model primarily identifies


product service created order generate revenues ways product service sold without well defined revenue model clear plan generate revenues new businesses likely struggle due costs able sustain revenue model business focus target audience fund development plans product service establish marketing plans begin line credit raise capital e commerce e commerce short electronic commerce trading products


services using computer networks internet electronic commerce draws technologies mobile commerce electronic funds transfer supply chain management internet marketing online transaction processing electronic data interchange edi inventory management systems automated data collection modern electronic commerce typically uses world wide web least one part transaction 's life cycle although may also use technologies e mail customer relationship management e business customer relationship management crm strategy used build relationships interactions customers potential future customers crm provides better customer service


allowing companies analyze past current future customers variety levels one elements essential business including e commerce allows companies grow succeed cannot done without technology formation bonds customers company crm impacts e commerce sites becoming essential part business successes interactively collecting considering customer data helps build company 's e crm capability leads company 's corporate success goal crm establish profitable long term


location aware services may serve reinforce economic inequality digital divide electronic commerce may responsible consolidation decline mom pop brick mortar businesses resulting increases income inequality author andrew keen long time critic social transformations caused internet recently focused economic effects consolidation internet businesses since businesses employ much fewer people per dollar sales traditional retailers security e business systems naturally greater security risks traditional business systems therefore important e business systems fully protected risks


far greater number people access e businesses internet would access traditional business customers suppliers employees numerous people use particular e business system daily expect confidential information stay secure hackers one great threats security e businesses common security concerns e businesses include keeping business customer information private confidential authenticity data data integrity methods protecting e business security keeping information secure include physical security measures well data storage data transmission anti virus


e businesses specifically keep information secure means protecting electronic records files unauthorized access well ensuring safe transmission data storage information tools encryption firewalls manage specific concern within e business ref name canada authenticity e business transactions pose greater challenges establishing authenticity due ease electronic information may altered copied parties e business transaction want assurance party claim especially customer places order submits payment electronically one


common way ensure limit access network trusted parties using virtual private network vpn technology establishment authenticity even greater combination techniques used techniques involve checking something know ie password pin something need ie credit card something ie digital signatures voice recognition methods many times e business however something pretty strongly verified checking purchaser 's something ie credit card something know ie card number ref name canada data integrity data integrity


answers question information changed corrupted way leads assurance message received identical message sent business needs confident data changed transit whether deliberately accident help data integrity firewalls protect stored data unauthorized access simply backing data allows recovery data equipment damaged ref name canada non repudiation concern deals existence proof transaction business must assurance receiving party purchaser cannot deny


authorized individuals business customers must assurance one else access systems information variety techniques address concern including firewalls access privileges user identification authentication techniques passwords digital certificates virtual private networks vpn much ref name canada availability concern specifically pertinent business 's customers certain information must available customers need messages must delivered reliable timely fashion information must stored retrieved required


availability service important e business websites steps must taken prevent disruption service events power outages damage physical infrastructure examples address include data backup fire suppression systems uninterrupted power supply ups systems virus protection well making sure sufficient capacity handle demands posed heavy network traffic ref name canada cost structure business internet supports e business cost maintain trillion outsourced dollars united states alone website custom crafted


maintained code maintenance burden enormous twenty first century look new businesses help standardize look feel internet presence business uniform nature help reduce cost maintenance cost structure e businesses varies lot industry operate two major categories commune characteristics first group fully digital businesses n't provide product services outside digital world includes example software companies social networks etc


significant operational cost maintenance platform costs almost unrelated every additional customer business acquires making marginal cost almost equal zero one major advantages kind business second group businesses provide services products outside digital world like online shops costs much harder determine common advantages traditional businesses lower marketing cost lower inventory cost lower payroll lower rent etc security solutions comes security solutions sustainable electronic business requires support data


integrity strong authentication privacy numerous things done order protect e business starting basic things like switch https old outdated http protocol vulnerable attacks furthermore things require full attention securing servers admin panels payment gateway security antivirus anti malware software using firewalls also must regular updates back data access data integrity several different ways prevent access data kept online one way use anti virus software something


people use protect networks regardless data '''e businesses''' use sure information sent received system clean ref name canada second way protect data use firewalls network protection firewall used restrict access private networks well public networks company may use firewall also ability log attempts network provide warnings happening beneficial keep third parties


network businesses use wi fi need consider different forms protection networks easier someone access look protected access virtual private networks internet protocol security ref name canada another option intrusion detection system system alerts possible intrusions companies set traps hot spots attract people able know someone trying hack area ref name canada encryption encryption actually part cryptography involves transforming texts messages code


software company purchase company needs sure keys registered certificate authority ref name canada digital certificates point digital certificate identify owner document way receiver knows authentic document companies use certificates several different ways used replacement user names passwords employee given access documents need wherever certificates also use encryption little complicated


normal encryption however actually used important information within code order assure authenticity documents well confidentiality data integrity always accompany encryption ref name canada digital certificates commonly used confusing people implement complications using different browsers means need use multiple certificates process adjusted easier use ref name canada digital signatures final way secure information online would use digital signature document


digital signature one else able edit information without detected way edited may adjusted reliability fact order use digital signature one must use combination cryptography message digest message digest used give document unique value value encrypted sender 's private key ref name canada advantages disadvantages advantages looking e business many advantages mostly connected making business easier benefits


implementing e business tools streamlining business processes much use technology easy set electronic business easy set even home requirements software device internet connection flexible business hours time barriers location based business encounter since internet available everyone time products services accessed everyone internet connection cheaper traditional business electronic business less costly traditional business


instead lower costs marketing sales e commerce allows actors industry advertise product service offer ie house rental generally lower costs promoting physically business disadvantages despite advantages also disadvantages need address common limitations electronic business lack personal touch products cannot examined felt final purchase traditional model personal customer experience electronic business mostly case another missing factor personal touch


could also online transactions delivery time traditional business enables instant satisfaction obtain product moment purchase electronic business possible always waiting period receive product example amazon assures one day delivery resolve issue completely improvement security issues scams could mentioned factor people 's distrust electronic business hackers easily get customers' financial personal details customer still finds hard trust electronic businesses lack


computer science '''imperative programming''' programming paradigm uses statements change program 's state much way imperative mood natural languages expresses commands imperative program consists commands computer perform imperative programming focuses describing ''how'' program operates term often used contrast declarative programming focuses ''what'' program accomplish without specifying details ''how'' program achieve result imperative procedural programming procedural programming type imperative programming program

Formal science
Computer science
Programming languages
Imperative programming


built one procedures also termed subroutines functions terms often used synonyms use procedures dramatic effect imperative programs appear constructed heavily procedural programming state changes localized procedures restricted explicit arguments returns procedures form structured programming onwards structured programming modular programming general promoted techniques improve maintainability overall quality imperative programs concepts behind object oriented programming attempt extend approach


procedural programming could considered step toward declarative programming programmer often tell simply looking names arguments return types procedures related comments particular procedure supposed without necessarily looking details achieves result time complete program still imperative since ''fixes'' statements executed order execution large extent rationale foundations imperative programming hardware implementation almost computers imperative ref group note reconfigurable computing notable exception ref nearly


computer hardware designed execute machine code native computer written imperative style low level perspective program state defined contents memory statements instructions native machine language computer higher level imperative languages use variables complex statements still follow paradigm recipes process checklists computer programs also familiar concepts similar style imperative programming step instruction physical world holds state since basic ideas


imperative programming conceptually familiar directly embodied hardware computer languages imperative style assignment statements imperative paradigm perform operation information located memory store results memory later use high level imperative languages addition permit evaluation complex expressions may consist combination arithmetic operations function evaluations assignment resulting value memory looping statements loops loops loops allow sequence statements executed multiple times loops either execute


statements contain predefined number times execute repeatedly condition met conditional branching statements allow sequence statements executed condition met otherwise statements skipped execution sequence continues statement following unconditional branching statements allow execution sequence transferred another part program include jump called ''goto'' many languages switch subprogram subroutine procedure call usually returns next statement call early development


high level programming languages introduction block enabled construction programs group statements declarations could treated one statement alongside introduction subroutines enabled complex structures expressed hierarchical decomposition simpler procedural structures many imperative programming languages fortran basic c abstractions assembly language ref name ref history imperative object oriented languages earliest imperative languages machine languages original computers languages instructions simple made hardware implementation easier hindered creation


complex programs fortran developed john backus international business machines ibm starting first major programming language remove obstacles presented machine code creation complex programs fortran compiled language allowed named variables complex expressions subprograms many features common imperative languages next two decades saw development many major high level imperative programming languages late algol developed order allow mathematical algorithms easily expressed even served operating system 's target language


computers mumps carried imperative paradigm logical extreme statements relying purely commands even extent making else commands independent connected intrinsic variable named test cobol basic attempts make programming syntax look like english pascal developed niklaus wirth c created dennis ritchie working bell laboratories wirth went design modula oberon needs united


concepts another object oriented language simula considered world 's first object oriented programming language developed bjarne stroustrup designed c object oriented language based c design c began first implementation completed late notable imperative languages drawing object oriented concepts perl released larry wall python released guido van rossum visual basic visual c included microsoft foundation class library mfc released microsoft respectively php released rasmus lerdorf


programming languages'' rd ed reading mass addison wesley publishing company ''originally based article 'imperative programming' stan seibert nupedia licensed gnu free documentation license'' programming paradigms


'''public transport''' also known '''public transportation''' '''public transit''' '''mass transit''' simply '''transit''' system transport passengers group travel systems available use general public unlike private transport typically managed schedule operated established routes charge posted fee trip rigid definition ''encyclop dia britannica'' specifies public transportation within urban areas air travel often thought discussing public transport dictionaries use wording like buses trains etc uk government covid guidance lists operators mention air

Applied science
Transportation
Mass transit


walking catching bus services access train stations ref name ref share taxis offer demand services many parts world may compete fixed public transport lines complement bringing passengers interchanges paratransit sometimes used areas low demand people need door door service ref name ptorg https webarchiveorg web http wwwpublictransportationorg aboutus defaultasp ref urban public transit differs distinctly among asia north america europe asia profit driven privately owned publicly traded mass transit real estate conglomerates predominantly operate public transit systems north america municipal transit authorities commonly run mass transit operations europe