上半年SSS125篇.docx

上半年SSS125篇.docx

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上半年SSS125篇

SSS120篇

20080101

ThisisScientificAmericans'60-SecondScience.IamSteveMirsky.Gotaminute?

HappyNewYear!

Anddon’tfeelbadabouttakingtodayoff.Afterall,you’vetraveledfar.AndI’mnottalkingaboutthetriphomefromthepartylastnight.AccordingtoNASA,justbybeingontheplanetearthinthelastyear,you’vezippedabout584millionmilesaroundthesuntogetbackwhereyouwere.Atanaveragespeedofabout67,000milesperhour.Again,nottalkingaboutthedrivehomelastnight.

Ofcourse,thetripwasnotaperfectcircle.AsKeplershowed,theearth’sorbitisanellipse,withthesunatoneofthetwofocalpoints.Healsofiguredouttheplanetgoesfasterwhenit’satperihelion,nearerthesun,thanwhenit’sataphelion,itsfurthestdistance.Whichwouldexplainwhysummerseemstozipby,excepttheseasonsareafunctionofthetiltoftheearth’saxis,notitsdifferentdistancesfromthesun.Andtheearthrotated365andaquartertimesduringitssweeparoundthesun.Thetriptook8,766hours.Or31,557,600seconds.Or525,960minutesjustlikethisone.

ThanksfortheminuteforScientificAmericans'60-SecondScience.I'mSteveMirsky.

20080102

ThisisScientificAmerican's60-SecondScience.I'mKarenHopkin.Thiswilljusttakeaminute.

Ifyoudon’tsubscribetotheDutchjournalEntomologiaExperimentalisatApplicata,youmighthavemissedthenewsaboutfleas:

thebestwaytogetridofahousefullofcatfleasistoreachforthevacuumcleaner.Theolduprightisnotonlylethaltoadultbugs,butitcompletelywipesouttheiryoung.ScientistsfromOhioStateUniversityhadsetouttodeterminewhatadditionalmeasuresmightbeneededtokillabunchofHoovered-upfleas:

burning,freezing,poisoning,maybeevenagoodoldfashionedbootstomping.Butitturnsoutthatgettingsuckedintoavacuumbagdoesthewholejob.

Theresearchersweresosurprisedbytheresults,theyrepeatedthestudyseveraltimes.Ineachexperiment,theysprinkledakitchencarpetwith100catfleas,eitheradultsorjuveniles.Andtheyfoundthatthevacuumsnuffedoutprettymuchallofthem.Whatmakesvacuumingsodeadlyishardtosay.Theresearchersadmitthattheydidnotconductapostmortemonanyofthedeceased.Buttheythinkitwasthephysicaltraumaofbeingsuckedthroughthebrushesthatgavefleasaone-waytickettothechitin-yard.Now,ifonlyscientistscouldcomeupwithasafewaytovacuumthecat.

ThanksfortheminuteforScientificAmerican's60-SecondScience.I'mKarenHopkin.

20080103

ThisisScientificAmericans'60-SecondScience,I'mSteveMirsky.Gotaminute?

Thescientificcommunityneedstobeinvolvedinpromotingscienceeducation,includingevolution.SosaystheJanuaryissueoftheFASEBJournal.FASEBistheFederationofAmericanSocietiesforExperimentalBiology.Sixteenotherorganizationsalsosignedontotherecommendation,includingtheNationalAcademyofSciencesandtheAmericanInstituteofPhysics.Thearticlenotesthattheintroductionofnonscience,suchascreationismandintelligentdesign,underminesfundamentalsofscienceeducation—suchasusingthescientificmethod,understandinghowtoreachscientificconsensusandtellingscientificexplanationsfornaturalphenomenaapartfromnonscientificones.

ThearticleincludedasurveyofathousandlikelyUSvoters.Thoseabletoanswersimplequestionsaboutplatetectonics,properantibioticuseandprehistorywerefarmorelikelytosupportevolutioneducation.SaidjournaleditorGeraldWeissman,“Thebottomlineisthattheworldisround,humansevolvedfromanextinctspecies,andElvisisdead.Thissurveyisawake-upcallforanyonewhosupportsteachinginformationbasedonevidenceratherthanspeculationorhope;peoplewanttohearthetruth,andtheywanttohearitfromscientists.

Thanksfortheminute,forScientificAmericans'60-SecondScience,I'mSteveMirsky.

20080104

ThisisScientificAmerican's60-SecondScience.I'mCynthiaGraber.Thiswilljusttakeaminute.

Bynowwe’veallheardabouttheplaceboaffect:

justbythinkingapillwillhelpcurewhatailsyou,itoftendoes.Well,itturnsoutdoctorssometimestakeadvantageoftheplaceboaffect.Yes,doctors-atleastdoctorsinChicago,-occasionallypurposelyprescribeplacebos.That’saccordingtoastudyintheJournalofGeneralInternalMedicine.

Of231internistsinChicagowhoansweredasurvey,45percentsaythey’veusedplacebosonoccasion.Themedicinesofchoiceincludedantibiotics,vitamins,ibuprofen,andamountsofmedicationtoosmalltobetherapeutic.Allprescribedforsituationsinwhichthosepillsshouldn1thavehadaneffectonthepatient’sparticularcomplaint.

Aboutathirdofthedoctorstoldpatientsthatthepillsmighthelpandcertainlywon’thurt.About20percentsimplytellthemthatit’smedicine.Soeventhoughprescribingplacebosremainscontroversial,clearlysomedocsaredoingit.Decadesago,physiciansprescribedplacebostodistinguishwhohadarealproblemandwhowasfakingit.Today,theyrecognizetherealityofthemind-bodyconnection,andthatplaceboscansometimesbejustwhatthedoctorordered.

Thanksfortheminute,forScientificAmerican's60-SecondScience.I'mCynthiaGraber.

20080107

ThisisScientificAmerican's60-SecondScience.I'mChelseaWald.Gotaminute?

Nooneeversitsinsilencethesedays.Butifwedid,manyofuswouldexperiencetinnitus—thatis,phantomnoise.It’snormallyahighringinglikethis.Butitcansoundlikecrickets,orbuzzing,ormusic.NowaBrazilianstudyhasfoundthatpeoplewon’thearthesenoisesasmuchiftheysimplyaren’tlistening.Volunteerswithnormalhearingwereputinsoundproofedrooms.Whentheyfocusedonlistening,almost70percentheardphantomnoises.Butwhentheyfocusedonseeing,only45percentheardnoises.Andwhensolvingapuzzle,only20percentheardnoises.

Somepeoplehaveconstant,debilitatingtinnitus.Forthem,thisstudysuggeststhattherapiestodivertattentionfromhearingcouldhelp.Foreveryoneelse,well,thebestwaytoavoidtinnitusmightbejustnottolistenveryhard.Infact,youshouldprobablyforgetaboutthisprogramaltogether.Oh,anddon’tthinkaboutpinkelephants.

ThanksfortheminuteforScientificAmerican's60-SecondScience.I'mChelseaWald.

20080108

ThisisScientificAmericans'60-SecondScience.IamCynthiaGraber.This'lljusttakeaminute.

Howfrequentarenightmaresfortoddlersandwhatcausesthem?

ThosearequestionsresearchersattheUniversityofMontrealhopetoanswer.Theyaskedparentsofaboutathousandchildrentoestimatetheoccurrenceoftheirchild'snightmaresfromagetwoandahalfthroughagesix.Theparentswerealsoquestionedabouttheirchild'sdisposition.First,itturnsoutthatnightmaresaren'tsofrequent.Aboutathirdoftheparentsreportednonightmaresatall.Andthenthereisthesecondresult:

kidswhoarecalleddifficultasearlyasfivemonthsweremorelikelytosufferfromnightmaresastoddlers.Andoneswhoatayearandahalfformoreanxious,morelikelytocry,andmoredifficulttocalmdownwerealsomorelikelytohavebaddreams.Thestudyauthorssaythismeanschildrenmaybe,well,likelittleadults.It'salreadywell-establishedthatadultstendtoexpressreallifestressandemotionalproblemsasnightmares.Theresearcherssuggestthatfocusingonthekidsday-timeissuesandonparentingtechniquesmayhelpbanishnight-timedemons.

ThanksfortheminuteforScientificAmericans'60-SecondScience.IamCynthiaGraber.

20080109

ThisisScientificAmericans'60-SecondScience,I'mSteveMirsky,gotaminute?

Ifyou'reinvadingmeat-eatingArgentinianantandyourunoutofprey,there'sonlyonethingtodoifyouwanttokeeponinvading-becomeavegetarian.Andthat'sjustwhatthecarnivorousArgentinianantsthathaveinvadedCaliforniadid,theyswitchedandbegantoeatvegetablematter.No,these2millimeter-longcrittersdidn'tdevelopmoralqualmsabouteatingmeat,theyaren'ttryingtosavetheplanet,theyjustranoutoftheirfirstchoice-nativeants.ResearcherswritingintheProceedingsoftheNationalAcademyofSciencessaythattheseantsgobbledupthenativeants,whichcanbe10timestheirsize.Thenewcomersthenhadnochoicebuttocarbo-load,switchingovertosuchsweettreatsashoneydewnectarproducedbyaphids.TheantswhicharebelievedtohavearrivedinCaliforniaonshipscarryingcoffeeandsugarfromArgentinain1890s,havecausedproblemsforbigcreaturesaswell.Thecoastalhornedlizardwhichdinedondomesticantshasdeclinedthenumbersbyabouthalfrecently,apparentlybecausethelizarddoesn'tparticularlycareforArgentinianfood.

ThanksfortheminuteforScientificAmericans'60-SecondScience,I'mSteveMirsky.

20080110

ThisisScientificAmericans'60-SecondScience.IamCynthiaGraber.This'lljusttakeaminute.

Somegenesthatcontributetodiseasescanbetracedbacktowhat'sknownasafoundermutation.It'sthefirstinstanceofthatspecificmutation,whichthengetscarriedbyallsubsequentgenerations.Mutationsinone'sspecificgeneareknowntogivecarriersa69%greaterriskofcoloncancerbytheageof80.Butitcanbetoughtofigureoutwhohasit.Luckily,theMormonChurchkeepsgreatfamilyrecords.ResearchersattheUniversityofUtahwereabletofigureoutthatthismutationoccurredinonly2extendedfamilies,oneinUtahandoneinNewYork.Sotheysuspectedthatsomewhereinhistorylurkedafounder.Theyusedcolonoscopyinformation,geneticanalysisoffamilymembersandgenealogicaldata,andMormonarchivestotracethemutationallthewaybacktoonecouple.WhenMr.andMrs.GeorgeFrycamet