時(shí)差N小時(shí):地球引力是否改變

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https://online2.tingclass.net/lesson/shi0529/0009/9697/594.mp3

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唐，為啥你無(wú)精打采?

Don't you know it's bad for you?

你不知道這對(duì)你不好?

Did you know that about 200 tons of debris strikethe Earth every day?

你知道每天大約200噸的碎片來(lái)到地球?

So I was thinking!

所以我在思考。

Although most of this stuff burns up in theatmosphere, the resulting dust still settles and addstothe Earth's mass.

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。

That's about half a million tons per year!

大約每年有50萬(wàn)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?

So if the earth keeps accumulating mass, doesn't that mean that the Earth's gravitationalpull hasbeen increasing?

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?

After all, gravity is directly proportional to mass.

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(shuō)你不能筆直端坐是因?yàn)榈厍蛞Ρ纫郧案鼜?qiáng)了?

Admit it, Yael;l–it's a good one.

承認(rèn)這一點(diǎn)吧，這是件好事。

Earth's mass in metric tons is approximately six followed by twenty-one zeroes.

地球的質(zhì)量按照公制噸位來(lái)衡量大約是6后面加21個(gè)0。

So assuming thatyour estimate is correct, and the Earth accumulates a half a million tons ofdebris every year.

所以假設(shè)你的估計(jì)是正確的，并且每年地球積累50萬(wàn)噸的碎片。

This means that in the sixty million years since dinosaurs existed the Earth would haveaccumulatedapproximately thirty trillion tons of meteoric debris.

這意味著自從恐龍存在以來(lái)的6000萬(wàn)年，地球已經(jīng)積累了大約30萬(wàn)億噸的流星碎片。

That's thirteen zeroes.

那是13個(gè)0。

The point is that a number with thirteen zeroes is minuscule relative to a number with twenty-four zeroes.

關(guān)鍵是13個(gè)零相對(duì)24個(gè)零而言是非常小的。

While thirty trillion tons sounds impressive, it is nothing compared to the Earth's total mass.

雖然30萬(wàn)億噸聽(tīng)起來(lái)很震撼，但是它與地球總的質(zhì)量相比還是微不足道的。

So it' s definitely not all that extra gravity that's making you slouch

所以很明確的是額外的重力不會(huì)使得你無(wú)精打采。