55 The Wheel

We often hear, “So-and-so is a big wheel.” We mean, of course, that the person is important. He or she makes things go around. Well, the real wheel also makes things go around. Without the wheel, today’s civilization would be impossible. Over 100 boxcars are loaded with cargo. One locomotive pulls them all. The 747 races down the runway. About 500 people are on a rocket with wheels and wings. How would these vehicles move at all without the wheel?

As children we’d jump on a bicycle or wagon and off we’d go. We never gave these wheeled vehicles a thought. Yet the wheel was a great invention! Who was the genius who thought of it?

There was no single genius. Things happened in bits and pieces. Some happened by chance and some by design. But it took hundreds and perhaps thousands of years of chance and insight.

Think of heavy dugout canoes and boats. They were rolled down to the shores on logs. There was no lifting or carrying. Just rolling chunks of log had moved deners. Putting a tapering through two of these chunks made an axle. After that, it was easy. This was the beginning of the solid wheel. The time was the fourth millennium B.C.

The spoked wheel came next, in about 2000 B.C. The place was along the Tigris River in present day Iraq. Wheels with spokes were for chariots. These were the chariots for racing. These were the wheels for battle.

The solid wheel was first. After that refinements were a sure bet.

55 轮子

我们常听到“某某是个大人物（字面意思：大轮子）”，当然，我们的意思是这个人很重要，他或她能让事情运转起来。嗯，真正的轮子也能让事情运转起来。没有轮子，当今的文明就不可能存在。100多节棚车装满了货物，一台机车就能拉动所有车厢。波音747在跑道上疾驰，大约500人乘坐带有轮子和机翼的火箭。要是没有轮子，这些交通工具怎么能运转呢？

小时候，我们会跳上自行车或马车，然后就出发了。我们从未想过这些带轮的交通工具。然而，轮子是一项伟大的发明！是谁想出这个主意的天才呢？

并没有单一的天才。事情是一点一点发生的，有些是偶然发生的，有些是设计好的。但这花费了数百年，或许数千年的偶然和洞察力。

想想沉重的独木舟和船只，它们是在圆木上被滚到岸边的，不用抬也不用搬，只是滚动圆木的大块就移动了货物。在两块这样的圆木中间穿一根锥形物就做成了车轴。在那之后，就简单了。这就是实心轮的开端，时间是公元前4000年左右。

辐条轮接下来出现，大约在公元前2000年，地点是在如今伊拉克的底格里斯河沿岸。带辐条的轮子用于战车，这些战车用于竞赛，也用于作战。

实心轮是最先出现的，在那之后，改进是必然的。