英国皇家科学院圣诞讲座：如何在太空中生存（2015）

so I am going to get you back on a scrubber,
我们会看到示数会再次下降
so we should see that number fall again.
好了 让我们来看那个示数
OK, so just let's watch that number.
刚刚是6 它立即就下降了
So it was six and it happens instantly.
他每次呼吸 过滤器都会去除二氧化碳
Every time he takes a breath, it removes the carbon dioxide...
它终于起效了
Ehh! It does work eventually.
我可不想在电视上杀了我的朋友
I wouldn't kill my friend... on television.
我们看到示数正在下降
And we're going to see it dropping now
这正是空间站的工作原理
and that's exactly how Space Station works.
丹 我要让你离开这个装置了
Dan, I'm going to take you off that,
因为我可不能在这儿杀了你 好了
cos I might kill you here. All right.
非常感谢 丹·塔尼 谢谢你
Thank you very much, Dan Tani. Thank you.
现在 丹 请你回到座位
Now, Dan, I'm going to let you get back to your seat
-等会儿见 -太棒了
- and I will see you later, I hope. - Great!
这就像件航♥天♥服
This is just like a space suit.
它的工作原理就像件航♥天♥服 真了不起
It works just like a space suit, it's awesome!
你的航♥天♥服可没有它这么大
Er, your space suit doesn't look as big as this.
是 航♥天♥服要小多了
No, yeah, it's smaller.
好吧 待会儿见 丹 掌声
All right. I'll see you later, Dan. Cheers.
我已经告诉你们如何将氧气带到空间站
So, I've told you how you get oxygen up to Space Station,
告诉了你们如何安全地储存它
I've told you how you store it safely,
告诉了你们如何去除二氧化碳
I've told you how you scrub the carbon dioxide out
这样就能对呼出的氧气稍作处理
so you can only top up your oxygen a little bit.
但是二氧化碳过滤器的问题在于
But the problem with a carbon dioxide scrubber is it doesn't work
如果二氧化碳到不了那个过滤器它就不会起效
if your carbon dioxide never gets to the scrubber.
现在 约翰正用一些相当简单的反应物
Now, John is doing a bit of chemistry here,
做一些化学反应
with some pretty simple reactants.
这里是柠檬酸和碳酸氢钠
So this is citric acid and bicarbonate of soda, right,
它们反应会生成二氧化碳
which makes carbon dioxide.
非常多 并会聚集在那个气缸中
Quite a lot, and it's gathering in that cylinder.
我需要一名志愿者
And to help us see how this is going to behave,
来帮我们完成接下来的实验
I need a volunteer.
我从这里上去 可以吗
I'll go all the way up here, shall I?
你来怎么样
And...how about....you?
过来站到这里面对观众
Come and stand here and face the audience.
-你叫什么 -凯特琳
- What's your name? - Caitlin.
凯特琳 凯特琳 好的
Caitlin. Caitlin, OK.
那么 凯特琳 我要给你展示
So, Caitlin, I'm going to show you
受重力影响的气体
that gases are affected by gravity.
通常我们不认为它们会受重力影响
Now, we don't really think of them as being affected by gravity,
但它们确实会
but they really are.
约翰要做一些事
So John is going to do something here.
你能看见他把东西倒进那个烧杯吗
Can you see him pouring that stuff into that beaker?
-你能 -是的
- You can? - Yeah.
我看不见他往那个烧杯里倒任何东西
I can't see him pouring ANYTHING into that beaker.
-你能看见烧杯里有什么吗 -看不见
- Oh. And can you see what's in that beaker? - No.
烧杯里什么也没有
There's nothing in that beaker.
约翰 你在干吗 你疯了吗
John, what are you doing, you crazy person?
但那个烧杯里确实有东西
But there IS something in that beaker.
烧杯里有二氧化碳
There's carbon dioxide in that beaker and...
你也许不信 但里面确实有
You don't believe me, but there really is
因为二氧化碳比空气重
and because carbon dioxide is heavier than air,
我希望它在玻璃杯里别跑掉
I'm hoping that it sits in that glass.
现在 凯特琳 我来点燃这些蜡烛
Now, Caitlin, I'm going to light these candles for you and...
你要拿起那个看上去什么也没有的烧杯
you're going to take that seemingly-empty beaker in a second
然后立刻把它倒在这些蜡烛上
and I just want you to pour it all over these candles.
你确定你倒完了吗 约翰
Are you sure you're done pouring, John?
-是的 -好的 太棒了
- Yeah. - OK, cool.
凯特琳 拿起那个烧杯 慢一点
So, Caitlin, pick up that beaker, just gently,
把它倒在那些蜡烛上 别停
and pour it on those candles, all the way across,
别停 继续 继续 继续 好的
all the way, keep going, keep going, keep going, yes!
我喜欢这个过程 是这样
I love that one. Now, here's the thing...
重力使较重的二氧化碳留在玻璃杯里
Gravity held the heavier carbon dioxide in the glass.
但重力也让杯子里的二氧化碳消失了
But what it also did was clear it away,
因为我能再次点燃这些蜡烛
because I can relight these candles.
而那些二氧化碳不能待在蜡烛上
That carbon dioxide doesn't sit on those candles,
它待不住因为气体对流带走了它
and it doesn't because convection takes it away again,
所以 二氧化碳一接触到蜡烛
so, as soon as the carbon dioxide hits the candles,
蜡烛熄灭了 冷空气
it falls down and cold air
和重空气下沉 热空气上升
and heavy air sinks and hot air rises
它们相互混合 就形成对流
and it mixes up and it ventilates the whole system,
所以 凯特琳 这就是你能倒出二氧化碳
so, Caitlin, that's why you could put it out
但它又没有留下的原因
but why the carbon dioxide isn't there any more.
凯特琳 非常感谢
Caitlin, thank you so much.
请回 谢谢你
Take your seat. Thank you.
在空间站 没有重力
So, on the space station, there is no gravitational force.
一切都是失重的
Everything is weightless,
所以热空气不能上升 冷空气不能下沉
so hot air cannot rise, cold air cannot sink,
所以没有气体混合 没有对流
and so there's no mixing, there's no convection
没有通风
and there are no draughts,
所以你无法把你呼出的空气
so you cannot get your air, your exhaled air,
弄进过滤器 除非有人工通风装置
to the scrubbers, unless you have an artificial draught.
在空间站 通风装置
On Space Station, the draught, like everything else
也是你赖以生存的装置之一
upon which you depend for your life,
通风装置是人工的
the draughts are artificial.
由一直嗡嗡作响的风扇组成
They're generated by fans that hum all the time.
提姆和我们说话时 我们总能听到
That's the humming sound you can always hear in the background
背景中的嗡嗡声
when Tim speaks to us.
约翰 非常感谢 谢谢你
John, thank you so much, thank you.
我们首次将人类送入太空后
Now, when we first started sending people into space,
就开始思考 他们身上会发生什么
we started to think, "Well, what's going to happen to them?"
几乎立刻
And, almost immediately,
我们就意识到他们的肌肉会萎缩
we realised that their muscles would waste.
任何哪怕只是见过健身房♥的人都知道
Now, anyone who's even looked at a gym knows
如果你不用肌肉 你就会失去它
that if you don't use it, you lose it
所以在太空中 你的肌肉会很快萎缩
and so your muscles waste very rapidly in space.
不仅是肌肉
And it's not just your muscles.
肌肉所附着的东西也会这样
It's the things your muscles are attached to.
这是我的朋友 朱丽叶
Now, this is my friend, Juliet,
她不是因为去过太空才这样
and she doesn't look like this because she's gone into space.
她在这里是为了解释太空飞行对骨骼的影响
She's here to explain the effect of space flight on bones.
你们可能认为骨头是
Now, you might think of bones as being one of those solid,
穴居人一度用来互砍的
inert objects that one caveman might
坚硬 没有变化的物质
once have hit another caveman with,
但实际上它是不断变化的动态组织
but actually they're very dynamic tissues.
骨组织沿外力施加方向
They remodel themselves constantly
不停地重组
along the lines of force that you apply to them.
因此多运动很重要
That's why it's important,
至少在你们这个年龄段多运动
at least at your age, to do lots and lots of exercise
就能生长出足够的骨质
so you can make sure that your bones think
以确保今后的骨骼生长
you need lots of bone for later in life.
当你处在站立姿势时
Now, your whole skeleton doesn't bear
整个骨架的荷重是不均匀的
the same sort of weight as you're standing up.
事实上 承重骨头
In fact, the weight-bearing bones,
主要的承重骨头
the principal weight-bearing bones,
承担大部分力量的部位是这里
the bones that bear the most weight are here -
这是跟骨 也就是你的脚跟
this is the calcaneus, your heel -
这里 股骨颈
here, the neck of your femur,
还有这里 你的腰椎
and here in your lower back.
我把朱丽叶转个方向
So I'm going to spin Juliet round.
在这 背部下方的腰椎
Down here, the bones of your lower back.
这几个处骨头承担了体重的绝大部分
So those are the areas that bear the most weight.
在太空中时
And when you go into space,
这些骨头不需要再承担这么多重量了
those bones don't need to bear any more weight
你的身体会认为
and your body says,
"既然不需要
"Well, why do I need to carry around
"干嘛还要留着这些多余的骨质呢"
"this excess bone If I'm not going to use it?"
这就体现了一个原则
And the rule applies -
不用即弃
if you don't use it, you lose it.
你的骨质开始流失
So your bones begin to waste.
这是个大问题