【英语时差8,16】为什么一天有24小时？

If you drop the ball, gravity will pull it toward the center of the earth, but will not diminish that extra eastward¹ speed. So as the ball falls it’ll outrun the ground and land slightly east of the straight-down point. Edwin H. Hall, a Harvard University physicist², looked for this effect in 1902. Working in an enclosed tower, he dropped one-inch bronze balls from a height of 75 feet into a pan of tallow. Hall was careful. He built a mechanism³ to release the ball without jiggle or spin, and a cloth tube to protect the path of fall from breezes. He used high-precision surveying telescopes to measure the position of a plumb⁴ line before each drop, and the position of the ball afterward⁵. He made a total of 948 drops. The average eastward deflection was just as predicted by Newton’s laws for a 75-foot tower at the latitude⁶ of Cambridge, Massachusetts: about one-seventeenth of an inch.

1 eastward   

adv.向东；adj.向东的；n.东方，东部

参考例句：

• The river here tends eastward.这条河从这里向东流。
• The crowd is heading eastward,believing that they can find gold there.人群正在向东移去，他们认为在那里可以找到黄金。

2 physicist   

n.物理学家，研究物理学的人

参考例句：

• He is a physicist of the first rank.他是一流的物理学家。
• The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。

3 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

4 plumb   

adv.精确地，完全地；v.了解意义，测水深

参考例句：

• No one could plumb the mystery.没人能看破这秘密。
• It was unprofitable to plumb that sort of thing.这种事弄个水落石出没有什么好处。

5 afterward   

adv.后来；以后

参考例句：

• Let's go to the theatre first and eat afterward. 让我们先去看戏，然后吃饭。
• Afterward,the boy became a very famous artist.后来，这男孩成为一个很有名的艺术家。

6 latitude   

n.纬度，行动或言论的自由(范围)，(pl.)地区

参考例句：

• The latitude of the island is 20 degrees south.该岛的纬度是南纬20度。
• The two cities are at approximately the same latitude.这两个城市差不多位于同一纬度上。