初中英語聽力mp3下載:地球的引力改變過嗎

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★英語聽力頻道為大家整理的初中英語聽力mp3下載:地球的引力改變過嗎,供大家參考。更多閱讀請查看本站英語聽力頻道。
    Has Earth’s Gravitational Pull Been Changing?
    地球的引力改變過嗎?
    Don, why are you slouching? Don’t you know it’s bad for you?
    唐,為啥你無精打采?你不知道這對你不好?
    Did you know that about 200 tons of debris strike the Earth every day? So I was thinking! Although most of this stuff burns up in the atmosphere, the resulting dust still settles and adds to the Earth’s mass. That’s about half a million tons per year!
    你知道每天大約200噸的碎片來到地球?所以我在思考。雖然這些東西中的大部分在大氣中燒掉了,但是燒完后的灰塵仍然沉淀并增添地球的質(zhì)量。大約每年有50萬噸。
    All right, but what does all this have to do with your posture?
    好的,但是所有這些與你的儀態(tài)有啥關(guān)系呢?
    Sit Up Straight
    筆直端坐
    So if the earth keeps accumulating mass, doesn’t that mean that the Earth’s gravitational pull has been increasing? After all, gravity is directly proportional to mass.
    所以如果地球持續(xù)累積其質(zhì)量,那不是意味著地球的引力也正在增加?畢竟,引力與質(zhì)量是成比例的
    Are you saying you can’t sit up straight because gravity is stronger now than it used to be?
    你說你不能筆直端坐是因為地球引力比以前更強了?
    Admit it, Yaël–it’s a good one.
    承認這一點吧,耶爾,這是件好事。
    Earth’s Mass
    地球的質(zhì)量
    Earth’s mass in metric tons is approximately six followed by twenty-one zeroes. So assuming that your estimate is correct, and the Earth accumulates a half a million tons of debris every year, this means that in the sixty million years since dinosaurs existed the Earth would have accumulated approximately thirty trillion tons of meteoric debris. That’s thirteen zeroes.
    地球的質(zhì)量按照公制噸位來衡量大約是6后面加21個0.所以假設(shè)你的估計是正確的,并且每年地球積累50萬噸的碎片,這意味著自從恐龍存在以來的6000萬年,地球已經(jīng)積累了大約30萬億噸的流星碎片。那是13個0。
    The point is that a number with thirteen zeroes is minuscule relative to a number with twenty-four zeroes. While thirty trillion tons sounds impressive, it is nothing compared to the Earth’s total mass. So it’ s definitely not all that extra gravity that’s making you slouch
    關(guān)鍵是13個零相對24個零而言是非常小的。雖然30萬億噸聽起來很震撼,但是它與地球總的質(zhì)量相比還是微不足道的。所以很明確的是額外的重力不會使得你無精打采。