我們半衰期的日子 | 徐泓

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當我還是鈾-238時，你對我的體重一直挑剔。我期待和祈禱了五十億年，終于進行了一次α衰變。兩個質子、兩個中子離開了我的身體，我變成了钍-234。

在麻省理工學院的公開課《化學原理》上，Catherine Drennan教授分享了一首化學詩Days of Our Half Lives（《我們半衰期的日子》）。視訊可見于https://open.163.com/newview/movie/free?pid=M6TUCF6FT&mid=M6TUL3NFT，從12分40秒至17分50秒。原視訊的中文翻譯基本正确，不過有些地方沒有了解英文的俏皮話，本文作者在下面給出了翻譯和注釋。

這首詩的作者是馬薩諸塞州韋爾斯利學院（Wellesley College）教授Mala Radhakrishnan，她曾經在麻省理工學院獲得化學博士學位。這首詩用一個感情故事的形式，講述了鈾-238衰變成一系列核素的過程。作者下了很大的功夫，使全詩不但韻律工整，而且在化學知識上也是正确的。

該詩選自Mala的化學詩集Chemistry for the Couch Potato。Couch是長沙發，美國人把那些吃飽飯後整天窩在沙發裡看電視的人稱為couch potato（沙發洋芋），非常形象地對應中文的“葛優躺”。閱讀“懶人的化學”，是個不錯的了解化學知識的方法。

Days of our half lives

My dearest love, I'm writing you to tell you all that I've been through.

我的至愛，我寫信告訴你我所經曆的一切。

I've changed my whole identity,

我的身份已經改變徹底，

But loved, I cannot pretend to be.

但曾經愛過，不能掩飾。

When I was uranium 238,

當我還是鈾-238時，

You were on my case to start losing weight.

你對我的體重一直挑剔。【注釋：on sb's case : 不停地指責】

For five billion years I hoped and I prayed,

我期待和祈禱了五十億年，

And finally I had an alpha decay.

終于進行了一次α衰變。

Two protons, two neutrons went right out the door,

兩個質子、兩個中子離開了我的身體，

And now I was thorium 234.

我變成了钍-234。

But my nucleus was still unfit for your eyes,

我的原子核仍入不了你的眼，

Not positive enough for its large size.

尺寸很大卻沒有足夠的正電。

But this time my half-life was really not very long,

但這次我的半衰期并不是很長，

Because my will to change was quite strong.

因為我改變自己的意願非常強。

It took just a month, not even a millennium,

隻用了一個月，不需要千年，

To beta decay into protactinium.

我變成镤，因為一次β衰變。

But you still rejected me right off the bat,

但你馬上拒絕了我：【注釋：right off the bat : （美國俚語）立刻，馬上】

Protactinium—who's heard of that?

镤——有誰聽說過？

So, beta decay, I did much more to become uranium 234.

于是又一次β衰變，我重新變回自己，

Myself again, but a new isotope,

以一種新的同位素，鈾-234。

You still weren't satisfied, but I still had hope.

你仍然不滿，但我心存希望。

Three alpha decays, it was hard, but I stayed on

我又經曆了三次α衰變，盡管艱辛，卻有始有終，

Through thorium, through radium, and then radon.

成為钍，成為鐳，然後成為氡。

I thought I would finally please you,

我想我終于能夠讓你歡愉，

My mass was a healthy 222.

以我健康的222的品質數。

But you said, although I like your mass,

然而你說，雖然你喜歡這個數字，

I do not want to be with a noble gas.

但是不想跟一個惰性氣體在一起。

You had a point, I wasn't reactive,

你說得有道理，我不具備活潑性，

So in order to please you, I stayed proactive.

是以為了取悅你，我保持積極性。

A few days later I found you and said,

幾天後我找到你，告訴你我是鉛，

Two more alpha decays and now I am lead.

為此我又進行了兩次α衰變。

You shook your head,

你搖了搖頭表示，

You were not too keen on my mass number of 214.

你不太喜歡我的品質數214。

I had a bad experience with that mass before,

确實有糟糕的體驗伴随着這個數字，

An unstable astatine walked right out the door.

曾經溜出門外有個不穩定的砹原子。

So in order to change, I went away,

我離開你為了繼續改變，

But all I could do was just beta decay.

可是我隻能進行β衰變。

My hopes and my dreams started to go under,

我的希望和夢想開始辜負，

Because beta decay doesn't change a mass number.

因為β衰變不改變品質數。

To bismuth, then polonium, I hoped and I beckoned,

變成铋，再變成钋，

我期待着，召喚着，

My half-life was 164 microseconds.

以164微秒的半衰期，

And then finally I alpha decayed,

終于α衰變為鉛-210，

And then I was lead with the prize worthy mass of 210.

一個值得稱贊的數字。

I've got to admit I was getting quite tired,

我不得不承認我已十分厭倦，

My patience with you had nearly expired.

我對你的耐心幾乎到了極限。

You were more demanding than any I dated,

你比我約會過的任何人都難滿足，

And much of my energy had already been liberated.

而我的大部分能量都已經釋放出。

But you still weren't happy, but you had a fix,

你仍然不高興，提出了方案以求滿意：

I really like the number of 206.

“其實我喜歡206這個數字”。

So I waited for years until the day,

于是我等待多年，直到這天，

Which began with another beta decay.

我開始再一次β衰變。

And then one more, and finally in the end

接着又一次，終究

I alpha-ed to lead 206, my friend.

我α衰變成了鉛-206。

To change any further I wouldn't be able,

至此，我無力進行任何改變，

No longer active, but happily stable.

不再活躍，變得穩定，我很情願。

It took me billions of years to do,

這花費了我億萬年時間，

And look how I changed and all just for you.

看我完全為你如何改變。

And wait, what did you say?

——等一下，你說什麼呢？

“You've gotten so old,

“你已經這麼老了，

that I'd rather be with a young lass of gold”

而我更願意和年輕的金姑娘在一起。”

Well, I gave up.

好吧，我放棄。

We're through, my pumpkin.

我們結束了，親愛的。【注釋：pumpkin : （口語）親愛的】

Shouldn't all my effort be counting for something?

難道我所做的努力什麼都不值？

Well, you won't be able to rule me anymore,

不，以後你再也不能對我控制，

Because I'm leaving you, not for one atom, but four.

因為我要離開你，不是為了一個，而是四個原子。

That's right. When you were away defusing,

沒錯，正當你在外面無所事事，

I met some chlorines that I found quite amusing.

我遇到了一些很有趣的氯原子。

So we're going to form PbCl4,

我們将要結合成四氯化鉛，

And you won't be hearing from me anymore.

我的情況你再也不會了然。

See, over the years I've grown quite wise,

經年的我已經豁然開朗，

I've learned that love is about compromise.

我明白了愛意味着互讓。

You still have half of your half-lives to live,

你的生命還有半個半衰期，

So now you go out there, it's your turn to give.

現在輪到你去給予和努力。

背景簡介：本文作者徐泓，同濟大學城市規劃系大學，中國石油大學（北京）化學工程與技術專業博士研究所學生。中國科普作家協會會員。作者授權風雲之聲首發。

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