There is of course a great deal we don't know, and much of what we think we know we haven't known, or thought we've known, for long. 当然，有大量的事情我们不知道，还有大量的事情我们现在或在过去很长时间里以为自己知道而其实并不知道。

Even the notion of the Big Bang is quite a recent one. 连大爆炸理论也是不久以前才提出来的。

The idea had been kicking around since the 1920s, when Georges Lemaitre, a Belgian priest-scholar, first tentatively proposed it, 这个概念自20世纪20年代以来一直很流行，是一位名叫乔治·勒梅特的比利时教士兼学者首先提出了这种假设。

but it didn't really become an active notion in cosmology until the mid-1960s when two young radio astronomers¹ made an extraordinary and inadvertent discovery. 但是，直到20世纪60年代中，这种理论才在宇宙学界活跃起来。当时，两位年轻的射电天文学家无意中发现了一种非同寻常的现象。

Their names were Arno Penzias and Robert Wilson. 他们的名字分别叫做阿诺·彭齐亚斯和罗伯特·威尔逊。

In 1965, they were trying to make use of a large communications antenna² owned by Bell Laboratories at Holmdel, New Jersey³, 1965年，他们在美国新泽西州霍尔姆德尔的贝尔实验室，想要使用一根大型通信天线，

but they were troubled by a persistent⁴ background noise—a steady, steamy hiss⁵ that made any experimental work impossible. 可是不断受到一个本底噪声--一种连续不断的蒸汽般的咝咝声的干扰，使得实验无法进行下去。

The noise was unrelenting and unfocused. 那个噪声是一刻不停的，很不集中的。

It came from every point in the sky, day and night, through every season. 它来自天空的各个方位，日日夜夜，一年四季。

For a year the young astronomers did everything they could think of to track down and eliminate the noise. 有一年时间，两位年轻的天文学家想尽了办法，想要跟踪和除去这个噪声。

They tested every electrical system. 他们测试了每个电器系统。

They rebuilt instruments, checked circuits, wiggled wires, dusted plugs. 他们重新组装了仪器，检查了线路，察看了电线，掸掉了插座上的灰尘。

They climbed into the dish and placed duct tape over every seam and rivet⁶. 他们爬进抛物面天线，用管道胶布盖住每一条接缝，每一颗铆钉。

They climbed back into the dish with brooms and scrubbing brushes 他们拿起扫帚和抹布再次爬进抛物面天线，

and carefully swept it clean of what they referred to in a later paper as "white dielectric material," 小心翼翼地把他们后来在一篇论文中称之为"白色电介质"的、

or what is known more commonly as bird shit. 用更通常的说法是鸟粪的东西扫得干干净净。

Nothing they tried worked. 可是他们的努力丝毫不起作用。