# 绝知此事要躬行

In the early part of the last century, speculation about ilfe life on Mars was more florid, particularly by the American astronaut astronomer Percival Lowell. Through his telescope in Arizona, Lowell convinced himself he saw swaths sways of vegetation come and go with the seasons. Of course, he didn't. What he really saw was shifted were shifting areas of sand dunes. But he also believed he'd found evidence of an advanced civilizationcivilisation.

" The canals are of various lengthlengths. Some stretch 2,500 miles from end to end. We are looking upon the results result of the world of some sort of intelligent beings.

"

Lowell's canals were just an optical illusion. , the results result of the imperfect image in his telescope and his over-excited imagination.

We got a better feeling for Mars as a life-friendly or unfriendly world. , when the first space probes visited in the 1960s and 70s, . It had a really thin atmosphere, and therefore hardly any shielding against radiation coming from space. It was a desert world with no liquid water on the surface, let alone canals.

But there was evidence that water had in the distant past, float in great volumes, and that it might still be there as ice undergroundunder ground. So even in 1972, scientists like NASA's Gerald Soffen entertained the possibility of quite fancy organisms alive on the surface today.

• Words worth to be remembered:
• speculation [,spekjʊ'leɪʃn]: n. 推测；eg:Every induction is a speculation. 所有归纳推理都是一种猜测。
• florid ['flɒrɪd] adj. 绚丽的 eg: The senator gave a florid speech.议员作了一番词藻华美的演说。
• dune [djuːn] n. （由风吹积而成的）沙丘 eg: Large dunes make access to the beach difficult in places. 在有些地方大沙丘使得靠近海滩很难。

## 譯文

“火星上有不同长度的运河。有些绵延2500英里。我们把这看作是火星世界里存在某种智慧生命才有的结果。”

##### Chaochen Wang 王　超辰
###### Assistant Professor

All models are wrong, but some are useful.