万物简史 第36期:埃文斯牧师的宇宙(5)

"There's something satisfying, I think," Evans said, "about the idea of light traveling for millions of yearsthrough space and just at the right moment as itreaches Earth someone looks at the right bit of skyand sees it. It just seems right that an event of thatmagnitude should be witnessed."

“我想，这还是挺令人满意的啊，”埃文斯说，“想一想，那个光在太空里走了几百万年，抵达地球的时候恰好有个人在不偏不倚地望着那片天空，结果看到了它。能亲眼目睹这样一个重大事件，这似乎是挺不错的。”

Supernovae do much more than simply impart a sense of wonder. They come in several types(one of them discovered by Evans) and of these one in particular, known as a Ia supernova, isimportant to astronomy because it always explodes in the same way, with the same criticalmass. For this reason it can be used as a standard candle to measure the expansion rate ofthe universe.

超新星远远不止让你产生一种惊奇感。它们分为几种类型(有一种是埃文斯发现的)，其中之一名叫Ia超新星，它对天文学来说尤其重要，因为这类超新星总是以同样的方式爆炸，拥有同样关键的质量。因此，它们可以被用做“标准烛光”--用来衡量其他恒星的亮度(因此也是衡量相对距离)的标准，从而衡量宇宙的膨胀率。

In 1987 Saul Perlmutter at the Lawrence Berkeley lab in California, needing more Ia supernovaethan visual sightings were providing, set out to find a more systematic method of searching forthem. Perlmutter devised a nifty system using sophisticated computers and charge-coupleddevices—in essence, really good digital cameras. It automated supernova hunting. Telescopescould now take thousands of pictures and let a computer detect the telltale bright spots thatmarked a supernova explosion.

1987年，由于需要比目测所能提供的更多的超新星数目，加利福尼亚州劳伦斯·伯克利实验室的索尔•珀尔马特开始寻找一种更加系统的搜寻方法。珀尔马特利用先进的计算机和电荷耦合器件设计了一个绝妙的系统--实质上是一流的数码相机。它使寻找超新星的工作自动化了。现在，天文望远镜可以拍下几千幅照片，然后利用计算机来发现能够说明发生了超新星爆炸的亮点。

In five years, with the new technique, Perlmutter and his colleagues at Berkeley found forty-two supernovae. Now even amateurs are finding supernovae with charge-coupled devices. "WithCCDs you can aim a telescope at the sky and go watch television," Evans said with a touch ofdismay. "It took all the romance out of it."

在5年时间里，珀尔马特和他的同事们在伯克利利用这种新技术发现了42颗超新星。如今，连业余爱好者也在用电荷耦合器件发现超新星。“使用电荷耦合器件，你可以把天文望远镜瞄准天空，然后走开去看电视，”埃文斯不大高兴地说，“那种神奇的味道已经不复存在了。”

I asked him if he was tempted to adopt the new technology. "Oh, no," he said, "I enjoy my waytoo much. Besides"—he gave a nod at the photo of his latest supernova and smiled—"I can stillbeat them sometimes."

我问埃文斯，他是不是想采取这种新技术。“哦，不，”他说，“我很喜欢自己的办法，而且”，他朝新近拍摄的一幅超新星照片点了点头，微微一笑，“有时候我仍能超过他们。”