十大科学常识中的谬误十大科学常识中的谬误Thereisnothingbetterthanabitofmythbusting(whichaccountsforthepopularityofthetelevisionprogramofthesamename),sohereweareagain,presentingyouwithanewlistofterriblycommonmisconceptionsandmyths–thistimeaboutscience.没有什么比“揭秘”更能吸引我们了（这也是为什么类似“大揭秘”这样的探索节目能够如此受到欢迎的原因）。所以今天这里将继续为大家介绍一些普遍存在的误解。这一期是关于科学上的误解。EvolutionaryImprovementsTheMyth:Evolutioncausessomethingtogofrom“lower”to“higher”Whileitisafactthatnaturalselectionweedsoutunhealthygenesfromthegenepool,therearemanycaseswhereanimperfectorganismhassurvived.Someexamplesofthisarefungi,sharks,crayfish,andmosses–thesehaveallremainedessentiallythesameoveragreatperiodoftime.Theseorganismsareallsufficientlyadaptedtotheirenvironmenttosurvivewithoutimprovement.Othertaxahavechangedalot,butnotnecessarilyforthebetter.Somecreatureshavehadtheirenvironmentschangedandtheiradaptationsmaynotbeaswellsuitedtotheirnewsituation.Fitnessislinkedtotheirenvironment,nottoprogress.误解十：进化是从“低级”向“高级”发展虽然自然选择将劣势基因从基因库中筛去是事实，但在有些情况下，不完美的基因存活了下来。比如菌类、鲨鱼、小龙虾、苔藓——这些生物在长时间内都保持基本不变。它们对自己的生存环境已经足够适应因此没有什么进化。其他种类的生物也许改变了很多，但并非一定进化得更高级了。有些生物改变了它们自己的生存环境，但它们的进化发展未必适合它们的新环境。适合与否与环境有关，而不是与是否向高级进化有关。HumansPopInSpaceTheMyth:Whenexposedtothevacuumofspace,thehumanbodypopsThismythistheresultofsciencefictionmovieswhichuseittoaddexcitementordramatotheplot.Infact,ahumancansurvivefor15–30secondsinouterspaceaslongastheybreatheoutbeforetheexposure(thispreventsthelungsfromburstingandsendingairintothebloodstream).After15orsoseconds,thelackofoxygencausesunconsciousnesswhicheventuallyleadstodeathbyasphyxiation.误解九：人在真空中会爆炸科幻小说和电影为了加强作品的戏剧性而将这一误解强加给我们。事实上，只要在暴露于真空之前中呼了气（这可以阻止肺部破裂和向血液输入空气），人体可以存活15至30秒。但过了这一时间段，由于缺乏氧气，人体将迅速失去意识，最后窒息而死。BrightestStarTheMyth:PolarisisthebrighteststarinthenorthernhemispherenightskySiriusisactuallybrighterwithamagnitudeof−1.47comparedtoPolaris’1.97(thelowerthenumberthebrighterthestar).TheimportanceofPolarisisthatitspositionintheskymarksNorth–andforthatreasonitisalsocalledthe“NorthStar”.PolarisisthebrighteststarintheconstellationUrsaMinorand,interestingly,isonlythecurrentNorthStaraspolestarschangeovertimebecausestarsexhibitaslowcontinuousdriftwithrespecttotheEarth’saxis.误解八：北极星是北半球夜空中最亮的星星。北极星并不是北半球夜空最亮的星星。最亮的星星是天狼星,它的视星等有-1.47等,北极星则只有1.97等（视星等越低，亮度越高）。北极星的重要性在于可以用来导航。它的位置十分接近北方，所以被称为“北方之星”。北极星是小熊星座最亮的星，更有意思的是，它是目前发现的唯一跟随地球的地轴不断改变位置的的恒星。FiveSecondRuleTheMyth:FoodthatdropsonthefloorissafetoeatifyoupickitupwithinfivesecondsThisisutterbunkumwhichshouldbeobvioustomostreaders.Iftherearegermsonthefloorandthefoodlandsonthem,theywillimmediatelysticktothefood.Havingsaidthat,eatinggermsanddirtisnotalwaysabadthingasithelpsustodeveloparobustimmunesystem.Iprefertohavea“how-tasty-is-it”rule:ifitissomethingreallytasty,itcansittherefortenminutesforallIcare–I...