导航

科学美国人60秒: 古代蛤蜊外壳揭开地球秘密

所属教程:科学美国人60秒科学系列 更新:03-21
00:00/00:00
点击单词,可查看发音和词义哦。

Ancient Clam Shell Reveals Shorter Day Length

古代蛤壳揭开地球秘密

Open up a clam, and you might see the making of a tasty snack. You probably wouldn't expect to find the history of our planet. But that's what researchers have been deducing from a 70-million-year-old fossil clam. They opened up this mollusk's secrets by drilling a small hole in its shell with a laser and analyzing the pattern of the growth.

打开一只蛤蜊,你可能会看到一份美味小吃的制作过程。但你可能不会期望找到我们星球的历史。但这是研究人员从7000万年前的蛤蜊化石中推断出来了。他们用激光在这只软体动物的外壳上钻了一个小洞,并分析了它的生长模式,从而揭开了它的秘密。

“So we make a cross section through this shell. You see the growth layers in the shell a bit like the layers in a tree. And that allowed us to count the number of days in the year that far back in time.”

“所以我们在外壳上做了一个横截面。你可以看到外壳中的生长层有点像树的层。这让我们可以计算很久以前一年中的天数。”

Niels de Winter, paleoclimatologist at the Free University of Brussels in Belgium. Using a laser to carefully count the number of growth rings in a 70-million-year-old fossil might seem like quite a laborious way to find out the number of days in a year. After all, we all know the answer is 365—and 366 in leap years—right?

尼尔斯·德·温特,是比利时布鲁塞尔自由大学的古气候学家。他用激光仔细地计算一个7000万年前的化石中年轮的数量,这似乎是一种相当费力的方法来计算一年中的天数。毕竟,我们都知道答案是365——闰年是366——对吧?

“That's interesting, because what we found is that there were actually not 365 days in the year; there were a few more.”

“这很有趣,因为我们发现实际上一年并没有365天;而是多几天。

You see, Earth's spin on its axis gradually slows down over time. The reduction is due to the friction from Earth's tides, which are driven by the moon's orbit.

随着时间的推移,地球自转的速度逐渐减慢。速断减慢是由于月球的轨道驱动产生的地球潮汐的摩擦引起的。

Back to that ancient clam. By measuring the rings on this mollusk's shell, the team was able to put a precise number on the history of this process. Seventy million years ago, the faster rotation of the Earth meant that there were just 23 and a half hours in a day.

回到那个古老的蛤蜊。通过测量这只软体动物壳上的年轮,研究小组能够对这一过程的历史给出一个精确的数字。七千万年前,地球自转速度的加快意味着一天只有23个半小时。

And measuring more shells might reveal more information about our planet's past.

测量更多的外壳可能会揭示更多关于我们星球过去的信息。

“It would also be very interesting to apply this on other shells—maybe also of the same time but also of different times so that we can map much better how this evolution took place.”

“将这一理论应用到其他贝壳上也会很有趣——也许是同一时期,但也可能是不同时期,这样我们就能更好地描绘出这种进化是如何发生的。”

Scientists already use fossilized shells to reveal details of the Earth's ancient climate. And now de Winter is hoping that he can read this preserved weather record in extra fine detail. This work could teach us about the climate of the distant past and maybe even help scientists better understand the climate change happening today.

科学家们已经使用化石外壳来揭示地球古代气候的细节信息。现在,德温特希望他能更详细地阅读这些保存下来的天气记录。这项工作可以让我们了解遥远的过去的气候,甚至可能帮助科学家更好地了解今天正在发生的气候变化。

“We might actually be able to extract things at a very, very high resolution about climate that far back in time. The prospect of being able to get the information at this scale is very exciting for a climate scientist like myself.”

“我们可能真的能够提取出非常高分辨率的关于很久以前的气候的信息。对于像我这样的气候科学家来说,能够获得如此大规模的信息是非常令人兴奋的。”

最受欢迎的教程

下载听力课堂手机客户端
随时随地练听力!(可离线学英语)