Gravity is a Mystery

Gravity is a Mystery

重力是个谜

Suppose you could dig a hole to the center of the earth. Suppose you dug right past the center. If you dug long enough and deep enough, you would come out in the Indian Ocean.

假设你可以挖一个洞直达地心。假设你挖过了中心。如果你挖得够长够深，你就能在印度洋里挖出来。

Sir Isaac Newton is the first person credited with discovering the force of gravity and how it kept objects in space (the earth and the moon) in their orbits. His theory is called the law of universal gravitational attraction. The Law of Universal Gravitation The attractive force of gravity between two particles is proportional to the product of their masses and inversely proportional to the square of the distance between them.

艾萨克·牛顿爵士被认为是第一个发现万有引力以及它如何使太空中的物体(地球和月球)保持在其轨道上的人。他的理论被称为万有引力定律。 万有引力定律 两个粒子之间的引力与它们质量的乘积成正比，与它们之间距离的平方成反比。

If you jumped into the hole, you would fall down. Down and down you would go. You would fall faster and faster toward the center of the earth. When you reached the center, you would be going so fast you could not stop. You would go right past the center.

如果你跳进洞里，你会掉下去的。你会越陷越深。 你会越来越快地向地心下落。当你到达中心时，你会跑得很快，停不下来。你会越过中心。

Then, on the other side, you would move up and away from the center of the earth. You would fall up for a while. You would go slower and slower. Then you would stop. You would almost get to the Indian Ocean--but not quite.

然后，在另一边，你会向上移动，远离地球的中心。你会跌倒一段时间。你会走得越来越慢。然后你就会停下来。你几乎就能到达印度洋了——但还没到。

Now you would fall back toward the center of the earth. You would go faster and faster, right past the center. But you would not quite reach your starting point.

现在你会落回地球的中心。 你会越来越快，越过中心。 但是你还没有到达你的起点。