古老的貝殼完全揭示瞭短短的七千萬年前

#大學英語聽力#

古老的貝殼完全揭示瞭短短的七千萬年前

A chunk of rock that had been buried in the ground for millions of years has become a new clock for understanding Earth’s rotation.

一塊被埋在地下數百萬年的巖石已經成為瞭解地球自轉的新時鐘。

Analysis of a fossilised Cretaceous-era bivalve shell has revealed that our planet’s days were half an hour shorter 70 million years ago.

對白堊紀雙殼類化石的分析表明,7000萬年前,我們星球的日子比以前短瞭半個小時。

In turn, knowing this can now help scientists to more accurately piece together the rate at which the Moon is slowly moving away from our planet.

反過來,瞭解這一點現在可以幫助科學傢更準確地拼湊出月球正在慢慢遠離我們的星球的速度。

Understanding how Earth’s rotation has changed over time is a pretty interesting challenge.

瞭解地球的自轉是如何隨著時間的推移而改變的是一個非常有趣的挑戰。

We can’t exactly go back and experience it or record it; instead, we have to rely on how our planet has recorded those changes over time.

我們不能確切地回到過去體驗或記錄它;相反,我們必須依賴於我們的星球是如何記錄這些變化的。

For instance, by studying how changes in solar radiation recorded in ancient rock matched up with the Sun’s cycles over tens of thousands of years, scientists were recently able to determine that Earth’s days were just 18 hours long around 1.4 billion years ago.

例如,通過研究在古老巖石中記錄的太陽輻射變化如何與數萬年來太陽的周期相匹配,科學傢最近能夠確定地球的日子大約在14億年前隻有18小時長。

But obtaining information on a more granular scale has proven somewhat challenging.

但事實證明,在更細粒度的規模上獲取信息具有一定的挑戰性。

This is where an extinct bivalve called Torreites sanchezi comes into play.

這就是一種被稱為Torreites sanchezi的已滅絕的雙殼類動物發揮作用的地方。

T. sanchezi comes from a group of bivalves called rudists that were wiped out in the Cretaceous-Palaeogene extinction event 66 million years ago, and nothing like them exists today.

T.sanchezi來自於一組被稱為rudists的雙殼類動物,它們在6600萬年前的白堊紀-古近紀滅絕事件中被消滅,今天沒有像它們這樣的生物存在。

They were sort-of shaped like a vase, with a lid at the wider end; these bivalves dominated reef ecosystems.

它們的形狀有點像花瓶,在更寬的一端有一個蓋子;這些雙殼類主導著珊瑚礁生態系統。

But they did have a few things in common with modern clams – one of which is that their shells grew at the rate of a layer per day.

但它們確實與現代蛤蜊有一些共同之處-其中之一是它們的貝殼以每天一層的速度生長。

You can probably guess where this is going.

你大概可以猜到這是怎麼回事。

Just as tree rings contain information about the year in which they grew, those shell rings can be analysed, too.

正如樹木年輪包含它們生長年份的信息一樣,這些貝殼年輪也可以被分析。

Published in News by Awesome.

發佈留言

發佈留言必須填寫的電子郵件地址不會公開。 必填欄位標示為 *