Particle - Wikipedia

In the physical sciences, a particle is a small localized object to which can be ascribed several physical or chemical properties, such as volume, density, ... Particle FromWikipedia,thefreeencyclopedia Jumptonavigation Jumptosearch Smalllocalizedobjectconsideredinphysicalsciences Forotheruses,seeParticle(disambiguation). Arcweldersneedtoprotectthemselvesfromweldingsparks,whichareheatedmetalparticlesthatflyofftheweldingsurface. Inthephysicalsciences,aparticle(orcorpusculeinoldertexts)isasmalllocalizedobjecttowhichcanbeascribedseveralphysicalorchemicalproperties,suchasvolume,density,ormass.[1][2]Theyvarygreatlyinsizeorquantity,fromsubatomicparticlesliketheelectron,tomicroscopicparticleslikeatomsandmolecules,tomacroscopicparticleslikepowdersandothergranularmaterials.Particlescanalsobeusedtocreatescientificmodelsofevenlargerobjectsdependingontheirdensity,suchashumansmovinginacrowdorcelestialbodiesinmotion. Thetermparticleisrathergeneralinmeaning,andisrefinedasneededbyvariousscientificfields.Anythingthatiscomposedofparticlesmaybereferredtoasbeingparticulate.[3]However,thenounparticulateismostfrequentlyusedtorefertopollutantsintheEarth'satmosphere,whichareasuspensionofunconnectedparticles,ratherthanaconnectedparticleaggregation. Contents 1Conceptualproperties 1.1Size 1.2Composition 1.3Stateofit 2N-bodysimulation 3Distributionofparticles 4Seealso 5References 6Furtherreading Conceptualproperties[edit] Particlesareoftenrepresentedasdots.Thisfigurecouldrepresentthemovementofatomsinagas,peopleincrowdsorstarsinthenightsky. Theconceptofparticlesisparticularlyusefulwhenmodellingnature,asthefulltreatmentofmanyphenomenacanbecomplexandalsoinvolvedifficultcomputation.[4]Itcanbeusedtomakesimplifyingassumptionsconcerningtheprocessesinvolved.FrancisSearsandMarkZemansky,inUniversityPhysics,givetheexampleofcalculatingthelandinglocationandspeedofabaseballthrownintheair.Theygraduallystripthebaseballofmostofitsproperties,byfirstidealizingitasarigidsmoothsphere,thenbyneglectingrotation,buoyancyandfriction,ultimatelyreducingtheproblemtotheballisticsofaclassicalpointparticle.[5]Thetreatmentoflargenumbersofparticlesistherealmofstatisticalphysics.[6] Size[edit] Galaxiesaresolargethatstarscanbeconsideredparticlesrelativetothem Seealso:Particlesize Theterm"particle"isusuallyapplieddifferentlytothreeclassesofsizes.Thetermmacroscopicparticle,usuallyreferstoparticlesmuchlargerthanatomsandmolecules.Theseareusuallyabstractedaspoint-likeparticles,eventhoughtheyhavevolumes,shapes,structures,etc.Examplesofmacroscopicparticleswouldincludepowder,dust,sand,piecesofdebrisduringacaraccident,orevenobjectsasbigasthestarsofagalaxy.[7][8] Anothertype,microscopicparticlesusuallyreferstoparticlesofsizesrangingfromatomstomolecules,suchascarbondioxide,nanoparticles,andcolloidalparticles.Theseparticlesarestudiedinchemistry,aswellasatomicandmolecularphysics.Thesmallestofparticlesarethesubatomicparticles,whichrefertoparticlessmallerthanatoms.[9]Thesewouldincludeparticlessuchastheconstituentsofatoms–protons,neutrons,andelectrons–aswellasothertypesofparticleswhichcanonlybeproducedinparticleacceleratorsorcosmicrays.Theseparticlesarestudiedinparticlephysics. Becauseoftheirextremelysmallsize,thestudyofmicroscopicandsubatomicparticlesfallintherealmofquantummechanics.Theywillexhibitphenomenademonstratedintheparticleinaboxmodel,[10][11]includingwave–particleduality,[12][13]andwhetherparticlescanbeconsidereddistinctoridentical[14][15]isanimportantquestioninmanysituations. Composition[edit] Aprotoniscomposedofthreequarks. Particlescanalsobeclassifiedaccordingtocomposition.Compositeparticlesrefertoparticlesthathavecomposition–thatisparticleswhicharemadeofotherparticles.[16]Forexample,acarbon-14atomismadeofsixprotons,eightneutrons,andsixelectrons.Bycontrast,elementaryparticles(alsocalledfundamentalparticles)refertoparticlesthatarenotmadeofotherparticles.[17]Accordingtoourcurrentunderstandingoftheworld,onlyaverysmallnumberoftheseexist,suchasleptons,quarks,andgluons.Howeveritispossiblethatsomeofthesemightturnuptobecompositeparticlesafterall,andmerelyappeartobeelementaryforthemoment.[18]Whilecompositeparticlescanveryoftenbeconsideredpoint-like,elementaryparticlesaretrulypunctual.[19] Stateofit[edit] Bothelementary(suchasmuons)andcompositeparticles(suchasuraniumnuclei),areknowntoundergoparticledecay.Thosethatdonotarecalledstableparticles,suchastheelectronorahelium-4nucleus.Thelifetimeofstableparticlescanbeeitherinfiniteorlargeenoughtohinderattemptstoobservesuchdecays.Inthelattercase,thoseparticlesarecalled"observationallystable".Ingeneral,aparticledecaysfromahigh-energystatetoalower-energystatebyemittingsomeformofradiation,suchastheemissionofphotons. N-bodysimulation[edit] Mainarticle:N-bodysimulation Incomputationalphysics,N-bodysimulations(alsocalledN-particlesimulations)aresimulationsofdynamicalsystemsofparticlesundertheinfluenceofcertainconditions,suchasbeingsubjecttogravity.[20]Thesesimulationsareverycommonincosmologyandcomputationalfluiddynamics. Nreferstothenumberofparticlesconsidered.AssimulationswithhigherNaremorecomputationallyintensive,systemswithlargenumbersofactualparticleswilloftenbeapproximatedtoasmallernumberofparticles,andsimulationalgorithmsneedtobeoptimizedthroughvariousmethods.[20] Distributionofparticles[edit] Mainarticle:Colloid Examplesofastableandofanunstablecolloidaldispersion. Colloidalparticlesarethecomponentsofacolloid.Acolloidisasubstancemicroscopicallydispersedevenlythroughoutanothersubstance.[21]Suchcolloidalsystemcanbesolid,liquid,orgaseous;aswellascontinuousordispersed.Thedispersed-phaseparticleshaveadiameterofbetweenapproximately5and200nanometers.[22]Solubleparticlessmallerthanthiswillformasolutionasopposedtoacolloid.Colloidalsystems(alsocalledcolloidalsolutionsorcolloidalsuspensions)arethesubjectofinterfaceandcolloidscience.Suspendedsolidsmaybeheldinaliquid,whilesolidorliquidparticlessuspendedinagastogetherformanaerosol.Particlesmayalsobesuspendedintheformofatmosphericparticulatematter,whichmayconstituteairpollution.Largerparticlescansimilarlyformmarinedebrisorspacedebris.Aconglomerationofdiscretesolid,macroscopicparticlesmaybedescribedasagranularmaterial. Seealso[edit] Wikiquotehasquotationsrelatedto:Particle Antiparticle Brownianmotion Corpuscularianism Fluidparcel Matter Particlecounter Particledetector Particlephysics Particlephysicsandrepresentationtheory Wigner'sclassification Particlesegregation Self-propelledparticle Listofparticles Wave–particleduality References[edit] ^ "Particle".AMSGlossary.AmericanMeteorologicalSociety.Retrieved2015-04-12. ^ "Particle".OxfordEnglishDictionary(3rd ed.).OxfordUniversityPress.September2005. ^ T.W.Lambe;R.V.Whitman(1969).SoilMechanics.JohnWiley&Sons.p. 18.ISBN 978-0-471-51192-2.Theword'particulate'means'oforpertainingtoasystemofparticles'. ^ F.W.Sears;M.W.Zemansky(1964)."EquilibriumofaParticle".UniversityPhysics(3rd ed.).Addison-Wesley.pp. 26–27.LCCN 63015265. ^ F.W.Sears;M.W.Zemansky(1964)."EquilibriumofaParticle".UniversityPhysics(3rd ed.).Addison-Wesley.p. 27.LCCN 63015265.Abodywhoserotationisignoredasirrelevantiscalledaparticle.Aparticlemaybesosmallthatitisanapproximationtoapoint,oritmaybeofanysize,providedthattheactionlinesofalltheforcesactingonitintersectinonepoint. ^ F.Reif(1965)."StatisticalDescriptionofSystemsofParticles".FundamentalsofStatisticalandThermalPhysics.McGraw-Hill.pp. 47ff.ISBN 978-0-07-051800-1. ^J.Dubinski(2003)."GalaxyDynamicsandCosmologyonMckenzie".CanadianInstituteforTheoreticalAstrophysics.Archivedfromtheoriginalon2021-11-02.Retrieved2011-02-24. ^ G.Coppola;F.LaBarbera;M.Capaccioli(2009)."SérsicgalaxywithSérsichalomodelsofearly-typegalaxies:AtoolforN-bodysimulations".PublicationsoftheAstronomicalSocietyofthePacific.121(879):437.arXiv:0903.4758.Bibcode:2009PASP..121..437C.doi:10.1086/599288. ^ "Subatomicparticle".YourDictionary.com.Archivedfromtheoriginalon2011-03-05.Retrieved2010-02-08. ^ R.Eisberg;R.Resnick(1985)."SolutionsofTime-IndependentSchroedingerEquations".QuantumPhysicsofAtoms,Molecules,Solids,Nuclei,Ions,CompoundsandParticles(2nd ed.).JohnWiley&Sons.pp. 214–226.ISBN 978-0-471-87373-0. ^ F.Reif(1965)."QuantumStatisticsofIdealGases–QuantumStatesofaSingleParticle".FundamentalsofStatisticalandThermalPhysics.McGraw-Hill.pp. vii–x.ISBN 978-0-07-051800-1. ^ R.Eisberg;R.Resnick(1985)."Photons—ParticlelikePropertiesofRadiation".QuantumPhysicsofAtoms,Molecules,Solids,Nuclei,andParticles(2nd ed.).JohnWiley&Sons.pp. 26–54.ISBN 978-0-471-87373-0. ^ R.Eisberg;R.Resnick(1985)."deBroglie'sPostulate—WavelikePropertiesofParticles".QuantumPhysicsofAtoms,Molecules,Solids,Nuclei,andParticles(2nd ed.).JohnWiley&Sons.pp. 55–84.ISBN 978-0-471-87373-0. ^ F.Reif(1965)."QuantumStatisticsofIdealGases–IdenticalParticlesandSymmetryRequirements".FundamentalsofStatisticalandThermalDynamics.McGraw-Hill.pp. 331ff.ISBN 978-0-07-051800-1. ^ F.Reif(1965)."QuantumStatisticsofIdealGases–PhysicalImplicationsoftheQuantum-MechanicalEnumerationofStates".FundamentalsofStatisticalandThermalDynamics.McGraw-Hill.pp. 353–360.ISBN 978-0-07-051800-1. ^ "Compositeparticle".YourDictionary.com.Archivedfromtheoriginalon2010-11-15.Retrieved2010-02-08. ^ "Elementaryparticle".YourDictionary.com.Archivedfromtheoriginalon2010-10-14.Retrieved2010-02-08. ^ I.A.D'Souza;C.S.Kalman(1992).Preons:ModelsofLeptons,QuarksandGaugeBosonsasCompositeObjects.WorldScientific.ISBN 978-981-02-1019-9. ^ USNationalResearchCouncil(1990)."Whatisanelementaryparticle?".Elementary-ParticlePhysics.USNationalResearchCouncil.p. 19.ISBN 0-309-03576-7. ^abA.Graps(20March2000)."N-Body/ParticleSimulationMethods".Archivedfromtheoriginalon5April2001.Retrieved2019-04-18. ^ "Colloid".EncyclopædiaBritannica.1July2014.Retrieved2015-04-12. ^ I.N.Levine(2001).PhysicalChemistry(5th ed.).McGraw-Hill.p. 955.ISBN 978-0-07-231808-1. Furtherreading[edit] "Whatisaparticle?".UniversityofFlorida,ParticleEngineeringResearchCenter.23July2010. D.J.Griffiths(2008).IntroductiontoParticlePhysics(2nd ed.).Wiley-VCH.ISBN 978-3-527-40601-2. M.Alonso;E.J.Finn(1967)."Dynamicsofaparticle".FundamentalUniversityPhysics,Volume1.Addison-Wesley.LCCN 66010828. M.Alonso;E.J.Finn(1967)."Dynamicsofasystemofparticles".FundamentalUniversityPhysics,Volume1.Addison-Wesley.LCCN 66010828. S.Segal(n.d.)."WhatisaParticle?-Definition&Theory".HighSchoolChemistry:HelpandReview.Study.com.Chapter4,Lesson6. "Abasicguidetoparticlecharacterization"(PDF).MalvernInstruments.2015. vteParticlesinphysicsElementaryFermionsQuarks Up(quark antiquark) Down(quark antiquark) Charm(quark antiquark) Strange(quark antiquark) Top(quark antiquark) Bottom(quark antiquark) Leptons Electron Positron Muon Antimuon Tau Antitau Electronneutrino Electronantineutrino Muonneutrino Muonantineutrino Tauneutrino Tauantineutrino BosonsGauge Photon Gluon WandZbosons Scalar Higgsboson Ghostfields Faddeev–Popovghosts HypotheticalSuperpartnersGauginos Gluino Gravitino Photino Others Axino Chargino Higgsino Neutralino Sfermion(Stopsquark) Others Axion Curvaton Dilaton Dualgraviton Graviphoton Graviton Inflaton Leptoquark Magneticmonopole Majoron Majoranafermion Darkphoton Preon Sterileneutrino Tachyon W′andZ′bosons XandYbosons CompositeHadronsBaryons Nucleon Proton Antiproton Neutron Antineutron Deltabaryon Lambdabaryon Sigmabaryon Xibaryon Omegabaryon Mesons Pion Rhomeson Etaandetaprimemesons Bottometameson Phimeson J/psimeson Omegameson Upsilonmeson Kaon Bmeson Dmeson Quarkonium Exotichadrons Tetraquark(Double-charmtetraquark) Pentaquark Others Atomicnuclei Atoms Exoticatoms Positronium Muonium Tauonium Onia Pionium Protonium Superatoms Molecules HypotheticalBaryons Hexaquark Heptaquark Skyrmion Mesons Glueball Thetameson Tmeson Others Mesonicmolecule Pomeron Diquark R-hadron Quasiparticles Anyon Davydovsoliton Dropleton Exciton Fracton Hole Magnon Phonon Plasmaron Plasmon Polariton Polaron Roton Trion Lists Baryons Mesons Particles Quasiparticles Timelineofparticlediscoveries Related Historyofsubatomicphysics timeline StandardModel mathematicalformulation Subatomicparticles Particles Antiparticles Nuclearphysics Eightfoldway Quarkmodel Exoticmatter Masslessparticle Relativisticparticle Virtualparticle Wave–particleduality Particlechauvinism Physicsportal vteElementsofnatureUniverse Space Time Energy Matter particles chemicalelements Change Earth Earthscience History (geological) Structure Geology Platetectonics Oceans Gaiahypothesis Future Weather Meteorology Atmosphere(Earth) Climate Clouds Rain Snow Sunlight Tides Wind tornado tropicalcyclone Naturalenvironment Ecology Ecosystem Field Radiation Wilderness Wildfires Life Origin(abiogenesis) Evolutionaryhistory Biosphere Hierarchy Biology (astrobiology) Biodiversity Organism Eukaryota flora plants fauna animals fungi protista Prokaryotes archaea bacteria Viruses Category Authoritycontrol:Nationallibraries Germany Israel UnitedStates Retrievedfrom"https://en.wikipedia.org/w/index.php?title=Particle&oldid=1073793107" Categories:MatterParticlephysicsHiddencategories:ArticleswithshortdescriptionShortdescriptionisdifferentfromWikidataArticleswithGNDidentifiersArticleswithJ9UidentifiersArticleswithLCCNidentifiersBroad-conceptarticles Navigationmenu Personaltools NotloggedinTalkContributionsCreateaccountLogin Namespaces ArticleTalk English Views ReadEditViewhistory More Search Navigation MainpageContentsCurrenteventsRandomarticleAboutWikipediaContactusDonate Contribute HelpLearntoeditCommunityportalRecentchangesUploadfile Tools WhatlinkshereRelatedchangesUploadfileSpecialpagesPermanentlinkPageinformationCitethispageWikidataitem Print/export DownloadasPDFPrintableversion Inotherprojects Wikiquote Languages AfrikaansالعربيةБеларускаяБългарскиBoarischBosanskiCatalàЧӑвашлаČeštinaChiShonaDanskالدارجةDeutschEestiEspañolEsperantoفارسیFrançaisGaeilge한국어हिन्दीBahasaIndonesiaÍslenskaItalianoעבריתಕನ್ನಡLatinaLombardNederlands日本語NorsknynorskOʻzbekcha/ўзбекчаਪੰਜਾਬੀPolskiRomânăРусиньскыйРусскийScotsSicilianuSimpleEnglishSlovenčinaСрпски/srpskiSrpskohrvatski/српскохрватскиTagalogதமிழ்TürkçeУкраїнськаTiếngViệtVõro粵語中文 Editlinks