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喝一杯重水会发生什么? – 译学馆
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喝一杯重水会发生什么?

What Happens If You Drink a Glass of Heavy Water?

科学秀由Brilliant.org网站支持 教你如何
SciShow is supported by Brilliant.org a problem-solving website that teaches you how to think like
像科学家一样思考
a scientist.
唔 这杯水十分清爽
Mmmm, a refreshing glass of cold water.
如果你认为我说的是H2O 那么你猜对了
If you think I’m talking about H-2-O, then you’re right.
而且我可以同样轻松地喝一点重水 又名氧化氘 分子式为D2O
But I could be sipping on heavy water, or deuterium oxide, aka D-2-O, just as easily.
好吧 没有那么简单 它非常昂贵 你必须到实验室供应商处购买
Well, not just as easily… it’s super expensive, and you have to, like, buy it from lab supply
但是你懂我的意思
stores, but you get my point.
氘是氢的一种形式 或者说是同位素 比氢多一个中子
Deuterium is a form of hydrogen, or isotope, with a bonus neutron, which makes it twice
使氘的重量 是我们所熟知的普通氢的两倍
as heavy as the regular hydrogen we all know and love.
因而当水分子中含有氘时 它会比普通水重10%
That’s why when there’s deuterium in water molecules, it’s about 10% heavier, and we
因此我们称它为重水
call it ‘heavy water.’
Patreon网站一位支持者Kutsop想知道 如果我们喝下一杯重水
And one of our patrons on Patreon, who goes by Kutsop, wanted to know what would happen
会发生什么
if you just drank a glass of heavy water.
喝入少量重水 甚至一两杯 是没关系的
Well, in small amounts — even a glass or two — heavy water is fine.
事实上 在人类很多营养实验中都会用到重水 它包含了一个氢同位素
In fact, in combination with an oxygen isotope, it’s used in lots of nutrition experiments
是一种非常有效的追踪能量消耗的方法
in humans because it’s a useful way to track how much energy you’re spending.
但是不要把所有杯子都装上纯重水
But don’t go filling up all your bottles with pure deuterium oxide, because too much
因为摄入过多重水会危及生命
will almost definitely kill you.
当老鼠体内重水含量达到三分之一时就会死亡
Mice and rats die when about a third of the water in their bodies has deuterium in it.
植物的情况也并不乐观 它会停止生长
Plants also aren’t big fans, and will stop growing.
这种毒性和动态同位素效应有关
The toxicity is related to what’s called the kinetic isotope effect.
就是说 大量额外的同位素将会减缓化学反应的速度
Basically, the extra mass of the isotope slows chemical reactions down — including all the
包括那些保证你生存的非常重要的反应
super important reactions that keep you not dead.
就重水来说 氘和氧之间的联系非常紧密
In the case of heavy water, the bonds between deuterium and oxygen are stronger than those
远超普通水中氧和氢之间的联系
between hydrogen and oxygen in normal water.
这意味着我们需要花费更多的能量来打破这种联系 于是其他的反应就变慢了
That means it takes more energy to break those bonds, which slows everything down.
目前并不完全清楚多少重水会使人死亡
It’s not totally clear how much heavy water would do a person in, but experts estimate
但是专家推测 体内重水含量超过10%将会出现不良反应
that anything more than 10% of your total water intake could start causing problems.
所以小喝一口没关系 但是不要猛灌
So a sip is okay, but don’t push it.
并且重水不会对你有任何帮助 还将产生额外的花费
Also it’s not going to help you at all, and it’s going to cost extra money.
我想不出你会这样做的理由
I don’t really know why you would do this.
此外 还有另一种重水是你一定要避开的 就是氚水
Still, there is a form of heavy water you should avoid: tritium oxide, or super-heavy
又叫超重水
water.
它含有的不是氢或者氘 而是氚 一种含有两个氢原子的
Instead of hydrogen or deuterium, it contains tritium, an isotope of hydrogen that has two
同位素
neutrons.
并且它是放射性的
And is radioactive.
只要放射性成分消失 氚化水就没有那么危险了
Now, as far as radioactive things go, tritiated water is pretty weak.
它会发出一种低能β粒子 这是一种不会穿透皮肤的电子
It emits low-energy beta particles, which are a type of electron that can’t penetrate skin.
但是喝掉氚化水就是另一回事了
But drinking them is another story.
有证据显示 贝塔粒子一旦进入体内将具有非常强的致癌能力
There’s some evidence that once inside the body, beta particles might even be better
远高于来自镭等物质中的高能伽马射线
at causing cancer than the higher-energy gamma rays that come from things like radium.
科学家们实际上并不确切了解氚化水到底有多危险
Scientists don’t actually have a great sense of how dangerous tritiated water is, they’re
他们认为不仅仅是放在杯子中喝掉会有危险 或许暴露在氚化水的环境中也是不好的
not just putting it in cups and having people try it, but they assume exposure is good.
我们天然地都会接到到一些小剂量的氚化水
We all come into contact with a tiny amount of it naturally, which isn’t a big deal.
但是氚化水通常用在核反应堆中 所以真正的担忧来自核泄漏
But because tritiated water is used in nuclear reactors, the real concern is when those reactors
或者可能发生的意外
leak, or if there’s an accident.
所以虽然我不建议你这么做 但是如果你非常想测试一下重水
So, I’m not recommending you do this, but if you really want to test out some heavy
并且不想发生意外 请确保他是氘化水 而非氚化水
water, just make sure we are talking about deuterium oxide,not tritiated oxide,if you don’t want to be a death person
但是对我来说 我坚持喝饮水机里流出来的水
Me however, I’ll just stick with the stuff that comes out of the water cooler at work,
因为它清爽好喝 并且由我所理解的成分组成
because it’s nice and cool and made up of normal things that I understand.
如果你想了解一些关于重水的奇奇怪怪的化学知识
If you liked learning about the weird chemistry of heavy water, you probably like getting
你需要变得聪明 保持敏锐
smart and staying smart.
Brilliant.org是一个问题解决型网站 教你如何像科学家一样思考
Brilliant.org is a problem-solving website that teaches you how to think like a scientist.
并且提供一些概念小测验 作为科学秀节目的补充
Brilliant presents short, conceptual quizzes that supplement what you have seen on SciShow.
记住这些知识的最好方法 就是在Brilliant网站确实用它来解决问题
A great way to retain that information is by actively solving problems on Brilliant.
每门课程都设置了简单并且富有挑战性的问题引导你共同探索 并配有互动性的图片和提问
Each course guides you through easy and challenging problems with interactive graphics and questions.
比如 每日物理课程教你关于冰箱 厕所 大气压力系统 核反应堆等的
One course, Physics of the Everyday, teaches you the science of your refrigerator and toilet,
科学知识
atmospheric pressure systems, nuclear reactors, and more.
在一堂课上 你会计算在地球的原油储存耗尽之前
In one lesson, you math your way through estimating what it would take to build a Dyson sphere
建造一个戴森球需要付出什么
before our oil reserves run out on Earth.
把问题分解为恰当的小概念 仔细思考每个部分 并且得出惊人的结论
By breaking the problem into bite-sized concepts, thinking clearly through each part, and building
你将会更好地理解戴森球背后的工艺
up to the stunning conclusion, You better understand the process behind Dyson spheres.
如果人类保持推动科学和数学进步的热情 一切都将成为可能
If humans keep a keen focus on advancing science and math, anything is possible.
已经有四百万用户加入了brilliant网站 快来加入他们 一起提升你的科学素养吧
4 million people are already using Brilliant, so join them in sharpening your STEM skills.
想要支持科学秀或者更多了解brilliant 可以登录brilliant.org/Scishow
To support SciShow and learn more about Brilliant, go to brilliant.org/SciShow and sign of for
免费注册
free.

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视频概述

喝重水请喝氘化水,保平安

听录译者

收集自网络

翻译译者

王随意

审核员

NL

视频来源

https://www.youtube.com/watch?v=VTLhKTi6_G0

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