萬(wàn)物簡(jiǎn)史 第36期:埃文斯牧師的宇宙(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，這還是挺令人滿(mǎn)意的啊，”埃文斯說(shuō)，“想一想，那個(gè)光在太空里走了幾百萬(wàn)年，抵達(dá)地球的時(shí)候恰好有個(gè)人在不偏不倚地望著那片天空，結(jié)果看到了它。能親眼目睹這樣一個(gè)重大事件，這似乎是挺不錯(cuò)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.

超新星遠(yuǎn)遠(yuǎn)不止讓你產(chǎn)生一種驚奇感。它們分為幾種類(lèi)型(有一種是埃文斯發(fā)現(xiàn)的)，其中之一名叫Ia超新星，它對(duì)天文學(xué)來(lái)說(shuō)尤其重要，因?yàn)檫@類(lèi)超新星總是以同樣的方式爆炸，擁有同樣關(guān)鍵的質(zhì)量。因此，它們可以被用做“標(biāo)準(zhǔn)燭光”--用來(lái)衡量其他恒星的亮度(因此也是衡量相對(duì)距離)的標(biāo)準(zhǔn)，從而衡量宇宙的膨脹率。

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，由于需要比目測(cè)所能提供的更多的超新星數(shù)目，加利福尼亞州勞倫斯·伯克利實(shí)驗(yàn)室的索爾•珀?duì)栺R特開(kāi)始尋找一種更加系統(tǒng)的搜尋方法。珀?duì)栺R特利用先進(jìn)的計(jì)算機(jī)和電荷耦合器件設(shè)計(jì)了一個(gè)絕妙的系統(tǒng)--實(shí)質(zhì)上是一流的數(shù)碼相機(jī)。它使尋找超新星的工作自動(dòng)化了。現(xiàn)在，天文望遠(yuǎn)鏡可以拍下幾千幅照片，然后利用計(jì)算機(jī)來(lái)發(fā)現(xiàn)能夠說(shuō)明發(fā)生了超新星爆炸的亮點(diǎn)。

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年時(shí)間里，珀?duì)栺R特和他的同事們?cè)诓死眠@種新技術(shù)發(fā)現(xiàn)了42顆超新星。如今，連業(yè)余愛(ài)好者也在用電荷耦合器件發(fā)現(xiàn)超新星。“使用電荷耦合器件，你可以把天文望遠(yuǎn)鏡瞄準(zhǔn)天空，然后走開(kāi)去看電視，”埃文斯不大高興地說(shuō)，“那種神奇的味道已經(jīng)不復(fù)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."

我問(wèn)埃文斯，他是不是想采取這種新技術(shù)。“哦，不，”他說(shuō)，“我很喜歡自己的辦法，而且”，他朝新近拍攝的一幅超新星照片點(diǎn)了點(diǎn)頭，微微一笑，“有時(shí)候我仍能超過(guò)他們。”