Scientific American October 2003.pdf

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1、CANCER-KILLINGVIRUSES•DANGEROUSMELTINGINTHEARCTICChina:TheNextSpaceSuperpowerOCTOBER2003$4.95WWW.SCIAM.COMStarClustersBornofGalacticCollisionsTheEconomicsofChildLaborProtectingFarmsagainstAgriculturalTerrorism—seepage20COPYRIGHT2003SCIENTIFICAMERICAN,INC.conten

2、tsoctober2003SCIENTIFICAMERICANVolume289Number4featuresASTRONOMY46TheUnexpectedYouthofGlobularClustersBYSTEPHENE.ZEPFANDKEITHM.ASHMANGlobularstarclusterswerethoughttobethestodgyoldcodgersoftheuniverse,butmany,infact,areyoung.MATERIALS52ArtificialMusclesBYSTEVENA

3、SHLEYNewpolymersthatactlikeelectricallycontrolledmusclescouldpowerrobotsandprostheticlimbs,replacespeakerdiaphragmsandliterallychangetheshapeofaviation.ENVIRONMENT60MeltdownintheNorthBYMATTHEWSTURM,DONALDK.PEROVICHANDMARKC.SERREZESeaiceandglaciersaremelting,per

4、mafrostisthawing,tundraisyieldingtoshrubs.HowwillitallaffecttheArctic—andtherestoftheplanet?BIOTECHNOLOGY68Tumor-BustingVirusesBYDIRKM.NETTELBECKANDDAVIDT.CURIELResearchersareinvestigatingtreatmentsforcancerthatwouldinfectthebodywithviruseslethalonlytotumorcell

5、s.HUMANSPACEFLIGHT76China’sGreatLeapUpward52RobotwalksusingBYJAMESOBERGartificialmusclesHowChinahopestobecomethenewestspacesuperpower.ECONOMICS84TheEconomicsofChildLaborBYKAUSHIKBASUCampaignsagainstchildlaborworkbetterwhentheycombinethelongarmofthelawwiththeinv

6、isiblehandofthemarketplace.www.sciam.comSCIENTIFICAMERICAN5COPYRIGHT2003SCIENTIFICAMERICAN,INC.departmentsSCIENTIFICAMERICANVolume289Number48SAPerspectivesBiotechnologyevenEuropecanlove.10HowtoContactUs10OntheWeb10110312Letters1850,100&150YearsAgo42StakingClaim

7、s20NewsScanIfthepatentofficeneedsagood,sharpkick,■Gapsindefendingfoodagainstterrorism.thistinkerercanprovideit.■Sexualityresearchducksaconservativebudgetax.■Theracetofindthesuperconductivitystate.44Insights■Playitagain:Treatingmusicians’repetitivestress.PekkaHaav

8、istooftheUnitedNationsworries■Mappingtheearth’sgravity.abouttheenvironmentalimpactofGulfWarII.■Flawsinstudiesofhormonereplacementtherapy?92WorkingKnowledge■BytheNumbers:Inte