科学理论(Scientific Theories)

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inscience,atheoryisareasonableexplanationofobservedeventsthatarerelated.atheoryofteninvolvesanimaginarymodelthathelpsscientistspicturethewayanobservedeventcouldbeproduced.agoodexampleofthisisfoundinthekiicmoleculartheory,inwhichgasesarepicturedasbeingmadeupofmanysmallparticlesthatareinconstantmotion.ausefultheory,inadditiontoexplainingpastobservations,helpstopredicteventsthathavenotasyetbeenobserved.afteratheoryhasbeenpublicized,scientistsdesignexperimentstotestthetheory.ifobservationsconfirmthescientist＇spredictions,thetheoryissupported.ifobservationsdonotconfirmthepredictions,thescientistsmustsearchfurther.theremaybeafaultintheexperiment,orthetheorymayhavetoberevisedorrejected.

scienceinvolvesimaginationandcreativethinkingaswellascollectinginformationandperformingexperiments.factsbythemselvesarenotscience.asthemathematicianjuleshenripoincaresaid,"scienceisbuiltwithfactsjustasahouseisbuiltwithbricks,butacollectionoffactscannotbecalledscienceanymorethanapileofbrickscanbecalledahouse."

mostscientistsstartaninvestigationbyfindingoutwhatotherscientistshavelearnedaboutaparticularproblem.afterknownfactshavebeengathered,thescientistestothepartoftheinvestigationthatrequiresconsiderableimagination.possiblesolutionstotheproblemareformulated.thesepossiblesolutionsarecalledhypotheses.inaway,anyhypothesisisaleapintotheunknown.itextendsthescientist＇sthinkingbeyondtheknownfacts.thescientistplansexperiments,performscalculations,andmakesobservationstotesthypotheses.withouthypothesis,furtherinvestigationlackspurposeanddirection.whenhypothesesareconfirmed,theyareincorporatedintotheories.