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1、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.Butintheacousticar
2、msracebetweenpredatorandprey,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
3、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:ThatsThomasNeiloftheUniver
4、sityofBristol.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.Andtheyresonateatfrequenciesthatprettymuchperfectlymatchthefrequenciesthatbatsuseforec
5、holocation.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,thatthesescalesaresuchashapeandsizethattheyreresonatingatjusttherigh
6、tfrequenciesthattheycanabsorbsoundenergyfromhuntingbats.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:Thereallycoolthingaboutmothsistheirscalesarealldifferentshapesandsiz
7、es.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:Thatrangecoversthefrequenciesofbatecholocationcallsfind
8、ingsNeilpresentedattheMeetingoftheAcousticalSocietyofAmerica.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
9、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
10、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
11、.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:Audioofbatc
12、allsHopkin:Batsuseecholocationtohuntfortheirmeals,andmothsareoftenonthemenu.Butintheacousticarmsracebetweenpredatorandprey,mothsalsohaveatrickortwouptheirsleeveor,actually,ontheirwings,becauseanewstudyshowsthatmothwingsarecoveredwithscalesthatabsorbsound,particularlytheultrasonicvarietypreferredbyba
13、ts.ThomasNeil:Somothandbutterflywingsarecoveredinlayersofscales.Thesearemadeofanaturallyoccurringpolymercalledchitin,whichisapolymeryoufindinmostinsectandcrustaceanexoskeletons.Hopkin:ThatsThomasNeiloftheUniversityofBristol.Hestartedoutbybombardingbitsofmothwingswithsoundandseeingwhatbouncedback.Nei
14、l:Wediscoveredthatmothscalesactuallyresonateinresponsetobeinghitwithultrasound.Andtheyresonateatfrequenciesthatprettymuchperfectlymatchthefrequenciesthatbatsuseforecholocation.Hopkin:Thatvibrationconvertssoundenergytomechanicalenergy,whichmufflestheechothatgetsbacktothebats.Neil:Thatprobablyhasnthap
15、penedbyaccident,thatthesescalesaresuchashapeandsizethattheyreresonatingatjusttherightfrequenciesthattheycanabsorbsoundenergyfromhuntingbats.Hopkin:Next,Neilandhiscolleaguesmodeledthesound-dampeningcapabilitiesofanarrayofdifferentscales.Neil:Thereallycoolthingaboutmothsistheirscalesarealldifferentsha
16、pesandsizes.Sowhatwefoundisthateachindividualscalewillresonateatslightlydifferentfrequenciesandthat,collectively,theyactuallyabsorbareallybroadbandrangeoffrequencies.Hopkin:ThatrangecoversthefrequenciesofbatecholocationcallsfindingsNeilpresentedattheMeetingoftheAcousticalSocietyofAmerica.Neil:Soitme
17、ansthatthemothsshouldbeprettywellprotectedfromawholehostofbatsthattheymightinteractwithoutinthewild.Hopkin:Butdoesthestrategyactuallywork?Neil:Sowedontactuallyknowhoweffectivethesescalesareatprotectingmothsintherealworld.Butfromeverythingwecanmodelandmeasureandpredict,itseemsliketheywouldhavequiteac
18、onsiderableadvantageintryingtohidethesemothsfrombatshuntingatnight.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