科學(xué)家們剛剛引發(fā)了已知宇宙中最冷的化學(xué)反應(yīng)

Scientists Just Triggered The Coldest Chemical Reaction in The Known Universe

科學(xué)家們剛剛引發(fā)了已知宇宙中最冷的化學(xué)反應(yīng)

Set in the middle of a mass of laser equipment, researchers have managed to trigger the coldest chemical reaction in the known Universe. This feat promises to reveal some essential truths about how the building blocks of matter react at ultra-low temperatures.

在一堆激光設(shè)備中間，研究人員成功地引發(fā)了已知宇宙中最冷的化學(xué)反應(yīng)。這一壯舉有望揭示物質(zhì)在超低溫度下如何反應(yīng)的一些基本事實(shí)。

How cold is the reaction exactly? We're talking in the region of 500 nanokelvin - just a few millionths of a degree above absolute zero. The frigid nature of this set-up is important, since at these sort of temperatures molecules tend to slow to the point of almost stopping.

反應(yīng)到底有多冷?我們說的是500納克爾文的區(qū)域——只比絕對零度高百萬分之一度。這種結(jié)構(gòu)的寒冷性質(zhì)很重要，因?yàn)樵谶@種溫度下，分子往往會減速到幾乎停止的程度。

If you want a chemical reaction to happen, tardy molecules are not what you'd typically be after. But in this case, the reduction in both temperature and speed gave the Harvard University-led team the opportunity to see something that's never been observed before: the moment when two molecules meet together and form... two new molecules.

如果你想要一個化學(xué)反應(yīng)發(fā)生，延遲分子不是你通常想要的。但在這種情況下，溫度和速度的降低讓哈佛大學(xué)領(lǐng)導(dǎo)的研究小組有機(jī)會看到以前從未觀察到的現(xiàn)象:兩個分子相遇并形成……兩個新的分子。

Probably in the next couple of years, we are the only lab that can do this, says physicist Ming-Guang Hu, from Harvard University.

來自哈佛大學(xué)的物理學(xué)家胡明光說:“可能在未來幾年，我們是唯一能做到這一點(diǎn)的實(shí)驗(yàn)室。”

Chemical reactions take just a picosecond, which makes trying to capture what happens in that time frame very tricky indeed. Even ultra-fast lasers acting as cameras can usually capture the start and end of a reaction, not what happens in the middle.

化學(xué)反應(yīng)只需要一皮秒，這使得試圖捕捉在那個時間段內(nèi)發(fā)生的事情變得非常棘手。即使是作為攝像機(jī)的超高速激光通常也能捕捉到反應(yīng)的開始和結(jié)束，而不是中間發(fā)生的事情。

Slowing the reaction in the extremely cold temperatures achieved by the team was therefore the perfect solution.

因此，在極低的溫度下減緩反應(yīng)是一個完美的解決方案。

Because [the molecules] are so cold, now we kind of have a bottleneck effect, says chemical biologist Kang-Kuen Ni, also from Harvard University.

同樣來自哈佛大學(xué)的化學(xué)生物學(xué)家倪康坤(Kang-Kuen Ni，音譯)說:“因?yàn)?這些分子)太冷了，現(xiàn)在我們有了瓶頸效應(yīng)。”

The absolute coldest temperature in the Universe is absolute zero - but it's impossible to achieve, because it means atoms would stop completely. We can, however, get close to it.

宇宙中最冷的溫度是絕對零度——但這是不可能實(shí)現(xiàn)的，因?yàn)檫@意味著原子會完全停止運(yùn)動。然而，我們可以接近它。

Ultra-low temperatures mean ultra-low energy, which in turn means a much slower reaction: two potassium rubidium molecules chosen for their pliability were delayed in the reaction stage for microseconds (millionths of a second).

超低的溫度意味著超低的能量，這反過來又意味著反應(yīng)要慢得多:兩個選擇的具有柔韌性的銣鉀分子在反應(yīng)階段被延遲了幾微秒(百萬分之一秒)。

A technique known as photoionisation detection was then used to observe what was happening to the two molecules, giving scientists invaluable real data to help inform their models and hypotheses.

隨后，一種被稱為光離子檢測的技術(shù)被用來觀察這兩個分子發(fā)生了什么，這為科學(xué)家提供了寶貴的真實(shí)數(shù)據(jù)，幫助他們建立模型和提出假設(shè)。

Being able to observe chemical reactions at such close quarters and at such a fundamental level opens up the possibility of being able to design new reactions too – an almost limitless number of combinations are imaginable, potentially useful in everything from material construction to quantum computing.

能夠在如此近的距離和如此基礎(chǔ)的水平上觀察化學(xué)反應(yīng)，也開啟了設(shè)計新反應(yīng)的可能性——人們可以想象到幾乎無限數(shù)量的組合，從材料結(jié)構(gòu)到量子計算，它們都有潛在的用途。

It's a journey that Kang-Kuen Ni has been on for years – working at incredibly small scales to observe and to control what happens when chemicals react with each other.

這是倪康坤多年來一直在從事的一項研究——在非常小的范圍內(nèi)觀察和控制化學(xué)物質(zhì)之間的相互反應(yīng)。

Now the team is investigating ways in which chemical reactions could be influenced or manipulated to order – either changing the energies involved before the reaction happens, or even nudging the molecules to alter the reaction while it's in progress.

現(xiàn)在，研究小組正在研究如何影響或操縱化學(xué)反應(yīng)以使之有序的方法——或者在反應(yīng)發(fā)生前改變所涉及的能量，或者甚至在反應(yīng)進(jìn)行中輕推分子來改變反應(yīng)。

With our controllability, this time window is long enough, we can probe, says Hu. "Now, with this apparatus, we can think about [influencing reactions]. Without this technique, without this paper, we cannot even think about this."

“由于我們的可控能力，這個時間窗口足夠長，我們可以進(jìn)行探索，”胡說。“現(xiàn)在，有了這個裝置，我們可以考慮(影響反應(yīng))。沒有這項技術(shù)，沒有這張紙，我們甚至無法思考這個問題。”

The research is published in Science.

這項研究發(fā)表在《科學(xué)》雜志上。