ChaseDream

标题: OG18倒数第二篇，这句话实在绞尽脑汁都看不懂，求翻译。 [打印本页]

---

作者: laughingwind    时间: 2018-1-4 15:45
标题: OG18倒数第二篇，这句话实在绞尽脑汁都看不懂，求翻译。

When asteroids collide, some collisions cause an asteroid to spin faster; others slow it down. If asteroids are all monoliths-single rocks-undergoing random collisions, a graph of their rotation rates should show a bell-shaped distribution with statistical “tails” of very fast and very slow rotators. If asteroids are rubble piles, however, the tail representing the very fast rotators would be missing, because any loose aggregate spinning faster than once every few hours (depending on the asteroid’s bulk density) would fly apart. Researchers have discovered that all but five observed asteroids obey a strict limit on rate of rotation. The exceptions are all smaller than 200 meters in diameter, with an abrupt cutoff for asteroids larger than that.

The evident conclusion-that asteroids larger than 200 meters across are multicomponent structures or rubble piles-agrees with recent computer modeling of collisions, which also finds a transition at that diameter. A collision can blast a large asteroid to bits, but after the collision those bits will usually move slower than their mutual escape velocity. Over several hours, gravity will reassemble all but the fastest pieces into a rubble pile. Because collisions among asteroids are relatively frequent, most large bodies have already suffered this fate. Conversely, most small asteroids should be monolithic, because impact fragments easily escape their feeble gravity.
标红的这句话到底是什么意思啊，尤其是最后这个独立主格结构with an abrupt cutoff for asteroids larger than that. 看了两个小时了，始终看不懂！求高人讲解！谢谢！

---

作者: 壹呀    时间: 2018-1-4 22:17
我也不太懂，试着回答一下。研究者发现，除了5个小行星之外，其他的小行星都遵从严格的转速限制。这5个例外小行星直径都小于200m，这个尺寸和比这个尺寸更大的小行星区分。

---

作者: j1imy    时间: 2018-1-11 00:56
本人理解
就是说所有直径大于200m的小行星都严格遵循这一个规律，不遵循规律的都是直径在200m以下的。就是这个规律在直径200m往下断掉了，直径小于200m的小行星不遵守这个规律，和其他大于的明显区分开来。

---

作者: tracy巨巨    时间: 2018-3-6 14:17
感觉这个cut off是形象的说法吧，就说别的都是200以上的，就那5个（好像生生被截断一样）比200小

---

作者: slgbond    时间: 2018-3-7 14:41
cutoff =stop; that =200 meters

---

作者: laughingwind    时间: 2018-5-16 16:56

When asteroids collide, some collisions cause an asteroid to spin faster; others slow it down. If asteroids are all monoliths-single rocks-undergoing random collisions, a graph of their rotation rates should show a bell-shaped distribution with statistical “tails” of very fast and very slow rotators. If asteroids are rubble piles, however, the tail representing the very fast rotators would be missing, because any loose aggregate spinning faster than once every few hours (depending on the asteroid’s bulk density) would fly apart. Researchers have discovered that all but five observed asteroids obey a strict limit on rate of rotation. The exceptions are all smaller than 200 meters in diameter, with an abrupt cutoff for asteroids larger than that.

The evident conclusion-that asteroids larger than 200 meters across are multicomponent structures or rubble piles-agrees with recent computer modeling of collisions, which also finds a transition at that diameter. A collision can blast a large asteroid to bits, but after the collision those bits will usually move slower than their mutual escape velocity. Over several hours, gravity will reassemble all but the fastest pieces into a rubble pile. Because collisions among asteroids are relatively frequent, most large bodies have already suffered this fate. Conversely, most small asteroids should be monolithic, because impact fragments easily escape their feeble gravity.

这一句话的理解要结合上下文，尤其第一句话末尾的rate of rotation。

前面说：行星碰撞之后，有的变快，有的变慢。但是如果是大块的行星随机碰撞之后，它们的旋转速率会呈现一个bell-shaped distribution，即"_n_"这个形状。也就是说，很慢的，和很快的，都很少，中间地带很多。但是如果是碎石群（前文中应该有谈到，行星分成整体单块儿monoliths-single的和小碎石集成的rubble piles）,就不会存在速度非常快的，因为那样就被甩出去了，分崩离析了。然后重点来了：研究者发现了五个行星是遵循一个严格限制的旋转速率的（也就是说这些行星碰撞之后速率不呈现bell-shaped distrubition，而是较为固定的转速），而这些行星都是直径小于200米的，而且相较于那些大于这个直径的行星而言，这个分水岭很明显，也就是但凡大于200米的行星，就都又呈现bell shaped distribution了。

---

作者: 梦季    时间: 2018-6-7 22:03
看一下！               

---

作者: newyork201999    时间: 2018-6-8 07:29

j1imy 发表于 2018-1-11 00:56
本人理解
就是说所有直径大于200m的小行星都严格遵循这一个规律，不遵循规律的都是直径在200m以下的。就是 ...

同意！               

---

作者: VideoHead    时间: 2019-1-24 12:07
后面这个cutoff理解了，这篇文章的第一题就很简单了。N-COUNT        可数名词 截止点;界限 A cut-off or a cut-off point is the level or limit at which you decide that something should stop happening. 理解为分界线或者区别 就很容易理解了。

---

作者: VideoHead    时间: 2019-1-24 12:11

laughingwind 发表于 2018-5-16 16:56
When asteroids collide, some collisions cause an asteroid to spin faster; others slow it down. If a ...

应该是除了这五个，其他的都遵循一个严格的转速限制吧，然后后面的exception是来说明这个五个是怎么回事。这个五个都是直径小于200米的。和那些直径大于200米的有一个明显的区别。

---

作者: 痴人也有梦    时间: 2019-2-16 09:51

VideoHead 发表于 2019-1-24 12:07
后面这个cutoff理解了，这篇文章的第一题就很简单了。N-COUNT        可数名词 截止点;界限 A cut-off or a cut-of ...

同意！
分割线/区分               

---

作者: 城桧吏    时间: 2021-8-17 11:09
Mark一下！               

---

欢迎光临 ChaseDream (https://forum.chasedream.com/)

Powered by Discuz! X3.3