天文学英文版PPT资料 (3)

UniverseEighthEditionRogerA.Freedman•WilliamJ.KaufmannIIICHAPTER1AstronomyandtheUniverseHomework1OnlinequizforChapter1(seesyllabusforURL)DUEFriday9/3by5PMByreadingthischapter,youwilllearn1-1Whatdistinguishesthemethodsofsciencefromotherhumanactivities1-2HowexploringotherplanetsprovidesinsightintotheoriginsofthesolarsystemandthenatureofourEarth1-3Starshavealifecycle—theyform,evolveovermillionsorbillionsofyears,anddie1-4Starsaregroupedintogalaxies,whicharefoundthroughouttheuniverse1-5Howastronomersmeasurethepositionsandsizesofcelestialobjects1-6Howtoexpressverylargeorverysmallnumbersinconvenientnotation1-7Whyastronomersusedifferentunitstomeasuredistancesinspace1-8WhatastronomycantellusaboutourplaceintheuniverseWhichofthefollowingstatementsistrue?A.Asolarsystemmaycontainbillionsofstars.B.StarsarespreadoutmoreorlessuniformlythroughouttheUniverse.C.TheMilkyWaycontainsavarietyofsolarsystems,stars,andgalaxies.D.Agalaxycontainsbillionsofstars.E.Asolarsystemcontainsbillionsofgalaxies.Q1.13Whichofthefollowingstatementsistrue?A.Asolarsystemmaycontainbillionsofstars.B.StarsarespreadoutmoreorlessuniformlythroughouttheUniverse.C.TheMilkyWaycontainsavarietyofsolarsystems,stars,andgalaxies.D.Agalaxycontainsbillionsofstars.E.Asolarsystemcontainsbillionsofgalaxies.Q1.13TheseparationbetweenthetwopointerstarsoftheBigDipperis5degrees.Whatisthisseparationinarcminutes?A.50B.60C.300D.500E.18,000Q1.4TheseparationbetweenthetwopointerstarsoftheBigDipperis5degrees.Whatisthisseparationinarcminutes?A.50B.60C.300D.500E.18,000A1.4Whatlengthsaremostconvenientlymeasuredinunitsofnanometers(10−9m)?A.DistancesbetweentheplanetsB.DistancesbetweencitiesonEarthC.DimensionsofthehumanbodyD.WavelengthsofvisiblelightE.DiameterofanatomQ1.6Whatlengthsaremostconvenientlymeasuredinunitsofnanometers(10−9m)?A.DistancesbetweentheplanetsB.DistancesbetweencitiesonEarthC.DimensionsofthehumanbodyD.WavelengthsofvisiblelightE.DiameterofanatomA1.6Whatlengthsaremostconvenientlymeasuredinastronomicalunits(AU)?A.DistancesontheEarthB.DistanceswithinthesolarsystemC.DistancesbetweenstarsinourGalaxyD.DistancesbetweengalaxiesE.OnlythelargestdistancesintheuniverseQ1.5Whatlengthsaremostconvenientlymeasuredinastronomicalunits(AU)?A.DistancesontheEarthB.DistanceswithinthesolarsystemC.DistancesbetweenstarsinourGalaxyD.DistancesbetweengalaxiesE.OnlythelargestdistancesintheuniverseA1.5WhatistheapproximatediameterofourGalaxy,theMilkyWay?A.50×106kmB.50astronomicalunitsC.50light-yearsD.50kiloparsecsE.10millionlight-yearsQ1.8WhatistheapproximatediameterofourGalaxy,theMilkyWay?A.50×106kmB.50astronomicalunitsC.50light-yearsD.50kiloparsecsE.10millionlight-yearsQ1.8KeyIdeasAstronomy,Science,andtheNatureoftheUniverse:Theuniverseiscomprehensible.Thescientificmethodisaprocedureforformulatinghypothesesabouttheuniverse.Thesearetestedbyobservationorexperimentationinordertobuildconsistentmodelsortheoriesthataccuratelydescribephenomenainnature.Observationsoftheheavenshavehelpedscientistsdiscoversomeofthefundamentallawsofphysics.Thelawsofphysicsareinturnusedbyastronomerstointerprettheirobservations.TheSolarSystem:Explorationoftheplanetsprovidesinformationabouttheoriginandevolutionofthesolarsystem,aswellasaboutthehistoryandresourcesofEarth.StarsandNebulae:StudyingthestarsandnebulaehelpsuslearnabouttheoriginandhistoryoftheSunandthesolarsystem.Galaxies:Observationsofgalaxiestellusabouttheoriginandhistoryoftheuniverse.AngularMeasure:Astronomersuseanglestodenotethepositionsandsizesofobjectsinthesky.Thesizeofanangleismeasuredindegrees,arcminutes,andarcseconds.Powers-of-TenNotationisaconvenientshorthandsystemforwritingnumbers.Itallowsverylargeandverysmallnumberstobeexpressedinacompactform.UnitsofDistance:Astronomersuseavarietyofdistanceunits.Theseincludetheastronomicalunit(theaveragedistancefromEarthtotheSun),thelight-year(thedistancethatlighttravelsinoneyear),andtheparsec.KeyIdeas