英译汉篇章翻译练习（4）
Thousands of years ago the ancient peoples found out that days were longer in summer than in winter, and nights were shorter. They knew that this had a great deal to do with the changes of the seasons and the growth of plants and animals. They determined through generations of painstaking observation that the day was shortest in the Northern Hemisphere on the 22nd of December, after which it gradually grew longer until the 21st of June, when the day was the longest in the year and the night was the shortest. After that, the day would begin to shorten again gradually. In the beginning, the actual dates of these two days had to be calculated for each individual year, and depended on what kind of calendar was being used.
The first calendar to fix these days on definite dates of the year was the solar calendar, which had 365 days in a year an d—every four year s—a “leap-year”with one extra day.
To an observer on earth, the sun seems to move farther and farther away from the equator to the north until on June 21st it seems to reach its furthest point north. Then it seems to “pause”for one day before it turns around and goes back. Then it goes further and further south until on December 22nd it appears to “pause” again for one day before swerving back north again. These two days are called the Summer Solstice and the Winter Solstice respectively.
Now we know that all this is caused by the movement of the earth around the sun. as the earth journeys around the sun, it spins on its own axis. This can be illustrated by a simple experiment. If you push a sharp stick through a rubber ball and twirl it with two fingers, the ball spins around I much the same way the earth is spinning at this very moment. The points where the stick comes through the ball correspond to the North and South Poles. If you twirl this ball at night directly in front of a bright light, you will notice that half the ball is lighted up while the other half is in the shade. That is just like our night and day. If you keep the stick strictly vertical to the light and twirl it at an even speed, any spot on the ball’s surface will be in the light and in the shade the same length of time.
If the earth were spinning just like this rubber ball, there would only be day and night on earth, but no seasons, and days would always be the same length as night s—12 hours each. But that is not how the earth spins. It spins with its axis tilted. Its axis is always at the angle to the plane of its orbi t—and angle of about 23.5 degrees.
It is this tilting that accounts for our four seasons and the lengthening and shortening of days and nights. For this reason also, the Equator (an imaginary line drawn around the earth at equal distance from the two poles) is not always directly under the sun’s rays. For six months the earth is tilted towards the sun, and the Northern Hemisphere gets more than its share of sunlight every day. Days are longer than nights, and what is more, the sun’s rays come down more perpendicularly instead of slanting down.
