地球自转一天已不足24小时，你的时间还够用吗？

忆清静丫

前段时间，某知名媒体刊登了这么一篇文章：《研究发现：地球的一天曾比现在长2.2小时》。

该报道引用美国一项研究，揭露地球在远古时代的自转速度比现在慢很多，以至于当时地球上的一天比现在长了2个多小时。
地球自转为什么会加快？现在还在加快吗？
答案很复杂。

曾经有研究表明，由于月球引力在地球上引起潮汐作用，地球自转其实正在变慢。
但在2022年6月29日，研究人员记录到地球自转速度创下新纪录，是有记录以来转得最快的一天，那一天地球的实际时间不仅不满24小时，还比以往任何一天都短。
2020年和2022年7月同样出现了差不多的数据，显示地球自转正在加快。
研究人员表示，现在的一天，可能并没有24小时。
在短时间内，我们无法用肉身感受到地球自转加快的微小变化，但如果在更长的时间跨度内，比如50年，地球自转持续加快，会发生什么呢？

下面是关于这个研究的详细报道，感兴趣的同学可以认真看下。
日子越来越短，时间越来越快，并不是我们的错觉，是正在发生的事实。
文章来源：https://www.forbes.com/sites/jamiecartereurope/2022/07/28/earth-is-suddenly-spinning-faster-why-our-planet-just-recorded-its-shortest-day-since-records-began/

Earth Is Suddenly Spinning Faster.

Why Our Planet Just Recorded1 Its Shortest Day Since Records2 Began?

地球自转突然变得更快了。

为什么我们的星球刚刚记录了自记录开始以来最短的一天？

record1 v 记录；记载
record2 n 记录；记载




Our planet set a record for completing one rotation faster than scientists had ever previously recorded, according to TimeAndDate.com. Earth rotated once around its axis on Wednesday, June 29, in 1.59 milliseconds less than 24 hours.
据TimeAndDate.com称，我们的星球创造了完成一次自转比科学家以往记录的任何一次都快的纪录。6月29日星期三，地球围绕地轴自转一次，用时比24小时少了1.59毫秒。
millisecond n 毫秒；千分之一秒（milli- + second）




Hang on! Earth takes exactly 24 hours to rotate once on its axis, right? Almost, yes, but not exactly.
等等！地球绕地轴自转一次正好需要24小时，对吧？几乎是的，但不完全准确。

What about the ‘leap seconds?’

“那‘闰秒’呢？”
Until a few years ago it had been thought that Earth’s rotation was slowing down after several successive (连续的) measurements by atomic clocks since 1973.
直到几年前，人们还认为，自 1973 年以来，经过几次原子钟的连续测量，地球自转正在减缓。
measurement n 测量 （measure + -ment）
atomic adj 原子的




The International Earth Rotation and Reference Systems Service (IERS) had even begun adding leap seconds every now and again to make up for the slower spin (it last happened on December 31, 2016).
国际地球自转和参考系统服务（IERS）甚至开始时不时地增加闰秒，来弥补地球自转减缓的影响（最后一次发生在2016年12月31日）。
every now and again 偶尔
make up 弥补




Over a longer time period that may still be the case — Earth’s rotation may, in general, still be slowing down.
在更长的时间范围内，情况可能仍然如此——地球自转总体上可能仍在变慢。
After all, the Moon is gradually slowing down the Earth’s rotation. Its gravitational pull causes tides and makes the Earth’s orbital path around the Sun slightlyelliptical.
毕竟，月球正逐渐减缓地球的自转。月球引力作用引起潮汐，使地球绕太阳的轨道稍微呈椭圆形。
gravitational adj 引力的；重力引起的（gravity + -ation +-al）
pull n 力；引力

How fast is Earth rotating?

地球自转有多快？
However, in the last few years the atomic clocks have shown that Earth rotation is now speeding up. In fact, we could be beginning a 50 year period of shorter days.
然而，在过去的几年中，原子钟显示地球自转正在加速。实际上，我们可能正迎来一个为期50年的短日长周期。
In 2020 scientists recorded the 28 shortest days since 1960. Last year that trend did not continue, with the shortest day in 2021 being longer than in the previous year.
2020年，科学家录得自1960年以来最短的28天。去年，这一趋势没有继续，2021年最短的一天比前一年最短的一天长。
However, on June 29, 2022 our planet completed its quickest-ever spin, followed quickly by a day that lasted 1.50 milliseconds less on July 26, 2022.
然而，在2022年6月29日，我们的星球完成了有史以来最快的一次自转，紧接着是2022年7月26日，那一天比24小时少了1.50毫秒。
The previous record for the shortest rotation was July 19, 2020, when the Earth’s rotation took 1.4602 milliseconds less than 24 hours.
上一个地球最短自转记录在2020年7月19日，当时地球自转时长比24小时少了1.4602毫秒。

Why is Earth speeding up?

为什么地球在加速？
The cause of the differing speed of Earth’s spin is unknown, but theories abound (有许多):
地球自转速度有差异的原因尚不清楚，但有很多相关理论。
differing adj 有差异的




lThe melting of the glaciers (冰川) means less weight on the poles
lMotions of our planet’s inner molten (熔融的) core
lSeismic (地震的) activity
lThe “Chandler wobble (摇晃)” — the movement of Earth’s geographical poles across its surface
冰川的融化意味着两极重量减轻
我们星球内部熔融态地核的运动
地震活动
“钱德勒摆动”——地球地理极点相对于地球表面的运动
Chandler wobble 钱德勒摆动是地球自转轴相对于地球表面的小幅度运动，由美国天文学家赛斯·卡罗·钱德勒发现于1891年。该运动以433日周期在地球表面摆动。钱德勒摆动和另一个周期一年的运动结合，使地球的极移周期为7年。

Why Earth’s rotational speed is important

为什么地球的自转速度很重要
Earth’s quickening rotation has consequences because atomic clocks — which are used in GPS satellites — don’t take into account the Earth’s changing rotation.
地球自转加速会产生一系列后果，因为用于GPS卫星的原子钟没有考虑到地球自转的变化。
quicken v （使）加快 / 加速
take into account 考虑到；顾及






If Earth spins faster then it gets to the same position a little earlier. A half-a-millisecond equates to 10-inches or 26 centimetres (厘米) at the equator. In short, GPS satellites — which already have to be corrected for the effect of Einstein’s general relativity theory (the curve (曲线) of space and time) — are quickly going to become useless.
如果地球自转加快，那么它将提早一点到达相同的位置。在赤道处，半毫秒相当于10英寸或26厘米。简而言之，早就需要根据爱因斯坦广义相对论（时空曲线）进行校正的GPS卫星——很快就会变得没有用处。
There are also potentially confusing consequences for smartphones, computers and communications systems, which synchronize with Network Time Protocol (NTP) servers. It’s defined as the number of seconds since 00:00:00 UTC on January 1, 1970.
与网络时间协议（NTP）服务器同步的智能手机、计算机和通信系统也可能会出现令人困惑的后果。网络时间协议被定义为协调世界时1970年1月1日零时零分零秒以来的秒数。
potentially adv 潜在地；可能的（potential + -ly）




To solve all this international timekeepers may need to add a negative leap second— a “drop second.” Though Earth may already be spinning as quickly as it ever will, with a slowdown inevitable.
为了解决所有问题，国际计时员可能需要增加一个负闰秒——一个“落差秒”。尽管地球可能已经以最快的速度自转，但减速是不可避免的。
inevitable adj 不可避免地




Only time will tell.
只有时间能证明一切。

检测题
阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
Our planet set a record for completing one rotation faster than scientists had ever previously recorded, according to TimeAndDate.com. Earth rotated once around its axis on Wednesday, June 29, in 1.59 milliseconds less (little) than 24 hours.
Hang on! Earth takes exactly 24 hours to rotate once on its axis, right? Almost, yes, but not exactly.
In the last few years the atomic clocks have shown that Earth rotation is now speeding up. In fact, we could be beginning a 50 year period of shorter days.
In 2020 scientists recorded the 28 shortest days since 1960. Last year that trend did not continue, with the shortest day in 2021 being longer than in the previous year.
However, on June 29, 2022 our planet completed its quickest-ever spin, followed quickly by a day that lasted 1.50 milliseconds less on July 26, 2022.
The previous record for the shortest rotation was July 19, 2020, when the Earth’s rotation took 1.4602 milliseconds less than 24 hours.
The cause of the differing speed of Earth’s spin is unknown, but theories abound (有许多):
The melting of the glaciers (冰川) means less weight on the poles
Motions of our planet’s inner molten (熔融的) core
Seismic (地震的) activity
The “Chandler wobble (摇晃)” — the movement of Earth’s geographical poles across its surface
Earth’s quickening rotation has consequences because atomic clocks — which are used in GPS satellites—don’t take into account the Earth’s changing rotation.
If Earth spins faster then it gets to the same position a little earlier. A half-a-millisecond equates to 10-inches or 26 centimetres (厘米) at the equator. In short, GPS satellites — which already have to be corrected for the effect of Einstein’s general relativity theory (the curve (曲线) of space and time) — are quickly going to become useless.
There are also potentially confusing consequences for smartphones, computers and communications systems, which synchronize with Network Time Protocol (NTP) servers. It’s defined as the number of seconds since 00:00:00 UTC on January 1, 1970.
To solve all this international timekeepers may need to add a negative leap second — a “drop second.” Though Earth may already be spinning as quickly as it ever will, with a slowdown inevitable.
Only time will tell.
1. According to the article, what happened on June 29 that set a new record?
A. Earth rotated faster than ever before.
B. Earth rotated slower than ever before.
C. Earth’s rotation matched exactly 24 hours.
D. Earth’s rotation stopped momentarily.
2. What was the general belief about Earth’s rotation until a few years ago?
A. It was speeding up.
B. It was slowing down.
C. It was remaining constant.
D. It was alternating between speeding up and slowing down.
3. What was the shortest day recorded in 2020?
A. December 31.
B. July 19.
C. June 29.
D. July 26.
4. What is one consequence of Earth’s quickening rotation for GPS satellites?
A. They become more accurate.
B. They need to be corrected for the changing rotation.
C. They start to slow down.
D. They become immune to relativity’s effects.

参考答案：ABBB