科学美国人60秒：飞蛾和蝙蝠的故事.docx

科学美国人60秒：飞蛾和蝙蝠的故事MothsHaveanAcousticInvisibilityCloaktoStayunderBatsRadar飞蛾和蝙蝠的故事KarenHopkin:ThisisScientificAmericans60-SecondScience.ImKarenHopkin.凯伦霍普金:这里是科学美国人60秒科学栏目。我是凯伦霍普金。 CLIP:Audioofbatcalls【音频：蝙蝠的叫声】Hopkin:Batsuseecholocationtohuntfortheirmeals,andmothsareoftenonthemenu.Butintheacousticarmsracebetweenpredatorandprey,mothsalsohaveatrickortwouptheirsleeveor,actually,ontheirwings,becauseanewstudyshowsthatmothwingsarecoveredwithscalesthatabsorbsound,particularlytheultrasonicvarietypreferredbybats.霍普金:蝙蝠利用回声定位来捕食，飞蛾也经常出如今它们的食谱上。但在捕食者和被捕食者之间的声音武器竞赛中，飞蛾也有一两个窍门实际上是在它们的翅膀上。由于一项新的研究表明，飞蛾的翅膀上覆盖着能吸收声音的鳞片，尤其是蝙蝠喜欢的各种超声波。ThomasNeil:Somothandbutterflywingsarecoveredinlayersofscales.Thesearemadeofanaturallyoccurringpolymercalledchitin,whichisapolymeryoufindinmostinsectandcrustaceanexoskeletons.托马斯尼尔：飞蛾和蝴蝶的翅膀上都覆盖着鳞片。它们是由一种叫做甲壳素的天然聚合物构成的，这种聚合物存在于大多数昆虫和甲壳类动物的外骨骼中。Hopkin:ThatsThomasNeiloftheUniversityofBristol.Hestartedoutbybombardingbitsofmothwingswithsoundandseeingwhatbouncedback.霍普金:这是布里斯托尔大学的托马斯尼尔。他先用声音轰击飞蛾的翅膀，看看有什么东西反弹回来。Neil:Wediscoveredthatmothscalesactuallyresonateinresponsetobeinghitwithultrasound.Andtheyresonateatfrequenciesthatprettymuchperfectlymatchthefrequenciesthatbatsuseforecholocation.尼尔：我们发现飞蛾的鳞片在被超声波击中时会产生共鸣。它们共振的频率与蝙蝠用于回声定位的频率非常吻合。Hopkin:Thatvibrationconvertssoundenergytomechanicalenergy,whichmufflestheechothatgetsbacktothebats.霍普金:这种振动将声能转化为机械能，进而抑制了传回蝙蝠的回声。Neil:Thatprobablyhasnthappenedbyaccident,thatthesescalesaresuchashapeandsizethattheyreresonatingatjusttherightfrequenciesthattheycanabsorbsoundenergyfromhuntingbats.这可能不是偶尔发生的，这些鳞片的形状和大小使它们能以适宜的频率共振，进而吸收捕猎蝙蝠的声音能量。Hopkin:Next,Neilandhiscolleaguesmodeledthesound-dampeningcapabilitiesofanarrayofdifferentscales.霍普金:接下来，尼尔和同事们模拟了不同程度的减声能力。Neil:Thereallycoolthingaboutmothsistheirscalesarealldifferentshapesandsizes.Sowhatwefoundisthateachindividualscalewillresonateatslightlydifferentfrequenciesandthat,collectively,theyactuallyabsorbareallybroadbandrangeoffrequencies.尼尔：飞蛾最酷的地方是它们的鳞片形状和大小各不一样。因而，我们发现，每一个音阶都会在略微不同的频率上产生共鸣，而总的来讲，实际上，这些鳞片吸收的声音频率范围很宽。Hopkin:ThatrangecoversthefrequenciesofbatecholocationcallsfindingsNeilpresentedattheMeetingoftheAcousticalSocietyofAmerica.霍普金:这个范围涵盖了蝙蝠回声定位呼叫的频率，这是尼尔在美国声学学会会议上提出的发现。Neil:Soitmeansthatthemothsshouldbeprettywellprotectedfromawholehostofbatsthattheymightinteractwithoutinthewild.尼尔：所以，这意味着这些飞蛾应该得到很好的保护，免受在野外与蝙蝠互动的影响。Hopkin:Butdoesthestrategyactuallywork?霍普金：但是这个策略真的有效吗?Neil:Sowedontactuallyknowhoweffectivethesescalesareatprotectingmothsintherealworld.Butfromeverythingwecanmodelandmeasureandpredict,itseemsliketheywouldhavequiteaconsiderableadvantageintryingtohidethesemothsfrombatshuntingatnight.尼尔：所以，我们并不知道现实中这些策略能多大程度上保护飞蛾。但从我们建模、测量和预测的一切来看，这些策略在帮助飞蛾躲避夜间捕食的蝙蝠有很大的优势。Hopkin:Foranybatsthatmightbelistening,Neilsaystheresnotmuchyoucandotothwartthismothmaneuver.霍普金:尼尔讲，对于任何可能在听的蝙蝠来讲，你无法阻止这种飞蛾的行动。Neil:Theonlyrealthingthattheycoulddowouldbetocallathigheramplitudes,sotoincreasethestrengthoftheirownecholocationcallssuchthattheechotheygotfromamothwouldbestronger.尼尔：蝙蝠唯一能做的就是用更高的振幅发出叫声，这样一来，它们本人的回声定位叫声的强度就会增加，这样从飞蛾那里得到的回声就会更强。Hopkin:Inotherwords,youmightcatchmoremothswithashoutthanwithawhisper.霍普金：换而言之，大喊比悄悄讲话能捕捉更多的飞蛾。MothsHaveanAcousticInvisibilityCloaktoStayunderBatsRadarKarenHopkin:ThisisScientificAmericans60-SecondScience.ImKarenHopkin. CLIP:AudioofbatcallsHopkin:Batsuseecholocationtohuntfortheirmeals,andmothsareoftenonthemenu.Butintheacousticarmsracebetweenpredatorandprey,mothsalsohaveatrickortwouptheirsleeveor,actually,ontheirwings,becauseanewstudyshowsthatmothwingsarecoveredwithscalesthatabsorbsound,particularlytheultrasonicvarietypreferredbybats.ThomasNeil:Somothandbutterflywingsarecoveredinlayersofscales.Thesearemadeofanaturallyoccurringpolymercalledchitin,whichisapolymeryoufindinmostinsectandcrustaceanexoskeletons.Hopkin:ThatsThomasNeiloftheUniversityofBristol.Hestartedoutbybombardingbitsofmothwingswithsoundandseeingwhatbouncedback.Neil:Wediscoveredthatmothscalesactuallyresonateinresponsetobeinghitwithultrasound.Andtheyresonateatfrequenciesthatprettymuchperfectlymatchthefrequenciesthatbatsuseforecholocation.Hopkin:Thatvibrationconvertssoundenergytomechanicalenergy,whichmufflestheechothatgetsbacktothebats.Neil:Thatprobablyhasnthappenedbyaccident,thatthesescalesaresuchashapeandsizethattheyreresonatingatjusttherightfrequenciesthattheycanabsorbsoundenergyfromhuntingbats.Hopkin:Next,Neilandhiscolleaguesmodeledthesound-dampeningcapabilitiesofanarrayofdifferentscales.Neil:Thereallycoolthingaboutmothsistheirscalesarealldifferentshapesandsizes.Sowhatwefoundisthateachindividualscalewillresonateatslightlydifferentfrequenciesandthat,collectively,theyactuallyabsorbareallybroadbandrangeoffrequencies.Hopkin:ThatrangecoversthefrequenciesofbatecholocationcallsfindingsNeilpresentedattheMeetingoftheAcousticalSocietyofAmerica.Neil:Soitmeansthatthemothsshouldbeprettywellprotectedfromawholehostofbatsthattheymightinteractwithoutinthewild.Hopkin:Butdoesthestrategyactuallywork?Neil:Sowedontactuallyknowhoweffectivethesescalesareatprotectingmothsintherealworld.Butfromeverythingwecanmodelandmeasureandpredict,itseemsliketheywouldhavequiteaconsiderableadvantageintryingtohidethesemothsfrombatshuntingatnight.Hopkin:Foranybatsthatmightbelistening,Neilsaystheresnotmuchyoucandotothwartthismothmaneuver.Neil:Theonlyrealthingthattheycoulddowouldbetocallathigheramplitudes,sotoincreasethestrengthoftheirownecholocationcallssuchthattheechotheygotfromamothwouldbestronger.Hopkin:Inotherwords,youmightcatchmoremothswithashoutthanwithawhisper.内容来自VOA英语学习网：s:/chinavoa/show-8817-242914-1.html