科学理论(Scientific Theories)

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

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

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