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Science and technology
科學(xué)技術(shù)
Astrochemistry
天體化學(xué)
The great test tube in the sky
空中的大試管
Space is one big chemistry set
宇宙是一個很大的化學(xué)裝置
MOST people think of the empty space between the stars as being, well, empty.
大多數(shù)人們認(rèn)為星星之間就是空無一物，但事實并非如此。
But it is not. It is actually filled with gas.
實際上有氣體彌散其中。
Admittedly, at an average density of 100-1,000 molecules per cubic centimetre, it is a pretty thin gas.
誠然，分子平均密度102-103/cm3的氣體非常稀薄。
But space is big, so altogether there is quite a lot of it.
不過由于空間很廣闊，氣體分子總體數(shù)量是可觀的。
Most of it, about 92%, is hydrogen.
大部分的氣體是氫，另外8%是惰性氣體氦。
A further 8% is helium, which is chemically inert.
還有一小部分由氧、碳、氮等其他元素構(gòu)成的分子。
But a tiny fraction—less than one-tenth of a percent—consists of molecules with other elements, such as oxygen, carbon and nitrogen, in them. Though these other elements are a mere soupon of the interstellar soup, they do give it real flavour.
雖然這些元素僅僅是“星際濃湯”輕微的調(diào)料，但它們確實增添了湯的味道。
Signs of life
生命的跡象
So far about 180 types of these molecular ingredients have been detected in space from their microwave spectra—the energy produced when molecules rotate around their chemical bonds.
到目前為止，人們已經(jīng)通過微波譜線探測出約180種分子成分。分子繞其化學(xué)鍵旋轉(zhuǎn)時，分子能級會發(fā)生改變，從而產(chǎn)生微波譜線。
There are two reasons for wanting to study them.
研究微波譜線有兩個原因。
One is that these molecules are probably the precursors of life.
一是分子可能是生命的預(yù)兆。
The other is that the rarefied nature of astrochemistry changes the way processes work.
二是天體化學(xué)其稀薄的屬性會改變化學(xué)反應(yīng)的過程。
It means the individual steps in chemical reactions can be disentangled from one another in a way that is hard—and sometimes impossible—on Earth.
人們可以用這種方式把化學(xué)反應(yīng)中獨立的一步從彼此步驟間分離出來，有時這在地球上很難實現(xiàn)。
And it allows reactions to happen that are unknown on Earth.
并且還有可能發(fā)生人類未知的化學(xué)反應(yīng)。
Now the astrochemists have a new tool:the Atacama Large Millimetre/submillimetre Array in northern Chile.
現(xiàn)在天體化學(xué)家有了新工具：阿塔卡馬大型毫米/亞毫米波天線陣。
It was officially opened on March 13th but has already been making discoveries, including the most intense bursts of star birth in the early universe.
3月13日ALMA正式運作，到現(xiàn)在已經(jīng)有了發(fā)現(xiàn)，例如宇宙早期恒星誕生最激烈的爆發(fā)。
ALMA consists of 66 dishes and is the world's most powerful radio telescope.
ALMA有66臺天線，是世界上最強勁的射電望遠(yuǎn)鏡。
At a cost of 1.3 billion it should provide a hundredfold increase in sensitivity and resolution over the best older instruments.
花費13億美元想必會使靈敏度分辨率比過去最好的儀器還要好百倍。
Those older telescopes had to focus on nebulae, where the interstellar gas is most concentrated.
以往的望遠(yuǎn)鏡必須關(guān)注星云，那里是星際氣體最集中之處。
And older telescopes can detect only strong, simple signals of the sort emitted by small molecules like carbon monoxide and hydrogen cyanide, which have two and three atoms respectively.
一個可用雙筒望遠(yuǎn)鏡看到的典例是氣體環(huán)繞恒星所形成的獵戶座的”劍”。并且老望遠(yuǎn)鏡只能探測到一氧化碳、氫氰化物等小分子釋放出的強的，簡單的信號。
Spotting more complex substances was almost impossible because their rotational energy is scattered by their numerous bonds across a wide range of frequencies.
而鑒別更復(fù)雜的物質(zhì)幾乎不可能，大量化學(xué)鍵占有很寬的頻率范圍，以至于旋轉(zhuǎn)能被散射掉。
ALMA, by contrast, can detect such things routinely.
相反ALMA可以輕易探測到這些信號：
It has already identified glycolaldehyde and acetone, molecules that have eight and ten atoms respectively.
它已經(jīng)鑒定出了乙醇醛和丙酮。
In particular, ALMA's masters, a consortium of research agencies from Canada, Chile, Europe, Japan, Taiwan and the United States, hope to find simple sugars and organic acids—molecules most researchers in the field believe were needed to get life going on Earth.
特別的，由加拿大、智利、歐洲、日本、臺灣及美國的財團(tuán)組成的研究機構(gòu)掌控ALMA，希望以此尋覓簡單的糖類和有機酸——該領(lǐng)域大多數(shù)研究人員認(rèn)為它們是地球上生命的必需之物。
The ability to study chemical reactions stage by stage will be equally important.
能夠研究化學(xué)反應(yīng)中的每一步同樣很重要。
High-school chemistry lessons, with their neat equations transforming, say, 2H+O into 2HO, miss out a plethora of intermediate steps such as the formation of hydroxyl, OH.
高中化學(xué)課上簡單的反應(yīng)方程式省略了大量的中間步驟。例如 2H? + O? = 2H?O 就沒有體現(xiàn)形成羥基的過程。
In a lab, these intermediates are often too short-lived to be detectable.
實驗室里，這些中間過程非常短暫，人們難以探測。
But in space an intermediate may hang around a long time before it encounters its partner in the next stage of a reaction.
不過在太空中，一個中間過程會持續(xù)很長時間，直到碰到下一步反應(yīng)的搭檔。
ALMA can see the microwave traces of such intermediates, and thus gain a better understanding of them.
ALMA可以看到這些中間過程的微波軌跡，因此研究者可以更好的了解這些過程。
There are also completely new reactions to discover.
還有全新的反應(yīng)有待人們發(fā)現(xiàn)。
Anthony Remijan, of America's National Radio Astronomy Observatory, who is one of the astronomers putting ALMA through its paces, is studying the formation of methyl formate, a compound widely used on Earth in applications from insulation to insecticides.
美國國家射電天文臺的Anthony Remijan是將ALMA引入這個方向的天文學(xué)家中的一員。他正在研究甲酸甲酯的形成過程。從絕緣體到殺蟲劑，可以說地球上到處都是甲酸甲酯。
Usually it is synthesised either from methanol and formic acid, or methanol and carbon monoxide.
通常它由甲醇和甲酸，或甲醇和一氧化碳合成。
But there is, in theory, a third route that uses formic acid and an unstable substance made from methanol and hydrogen.
但是在理論上，還可以使用甲酸和一種不穩(wěn)定的物質(zhì)來制造甲酸甲酯。
This has not been seen in an Earthly laboratory, but Dr Remijan thinks it is an important pathway in space, and ALMA should soon tell him if he is right.
這還沒有在地球上的實驗室中發(fā)現(xiàn)，但Remijan博士認(rèn)為在太空中這是一個重要的過程。ALMA應(yīng)該很快就會告訴他他是否正確。
Probably, that particular discovery will have no practical consequences.
也許，上述特別的發(fā)現(xiàn)不會產(chǎn)生實用效果。
The known syntheses are effective, and methyl formate is already cheap.
甲酸甲酯熟知的合成方法很有效，而且它很便宜。
But it will prove a principle about using the cosmos as a chemistry laboratory, and the hope is that similar findings about other molecules that are harder to make may allow chemical engineers at home to reformulate their processes.
但是，這證明了一個理念：用宇宙充當(dāng)化學(xué)實驗室。希望有關(guān)其他較難制造的分子的類似發(fā)現(xiàn)能夠讓化學(xué)工程師在家里重新制定它們的合成過程。
If that happens, the test tube in the sky really will have proved its worth.
如果可以，天空中的試管確實有其價值。
