英国皇家科学院圣诞讲座：如何在太空中生存（2015）

has some very exotic sources of radiation.
对着这本书
Point it at this book.
夏洛特 这是本什么书
Charlotte, what is this book?
这是1903年威廉·克鲁克斯使用的笔记本
This is notebook from William Crookes from 1903.
我记得他就是首位制♥造♥了
I remember he's the bloke who made the very first medical -
这不太妙啊
this is not good,is it?
-制♥造♥了医用X射线管的人 -是的
- medical X-ray tubes. - Yes.
听起来放射性很强
That sounds very radioactive.
我来拿吧
I might take that.
好 这个笔记本
All right, now this book,
他是在这一页里提到
this is the page where he was talking about
-使用镭盐吗 -是的
- messing around with some radium salts? - Yes.
镭盐具有放射性
That's radioactive stuff.
我觉得他写这一页时
I think he was messing around
就是在乱弄
when he was writing this page.
放射性最强的一处在哪儿
Which is the worst bit on this book?
-在折痕上 -好
- Down the crease. - OK.
一点儿都不好
That's not good at all.
好吧
OK.
放射性非常非常强
It's very, very, very radioactive.
夏洛特 这本书保存在哪儿呢
Where do you keep this book, Charlotte?
在皇家科学院档案馆
In the RI Archives.
是的 还有呢
Yes. But what...
-放在金属盒里 -金属盒子 好的
- In a metal box. - In a metal box. OK.
只要我们不吃掉或舔这本书就没事 懂了吗
Now, it's OK so long as we don't eat or lick the book. OK?
所以 不要吃掉 也不要舔这本书
So, do not eat or lick the book.
它告诉我们放射性的强度 塞莱斯特
Now, all that does is tell us how much radiation, Celeste.
再来做一件更有趣的事
So, to do something rather more interesting,
我们想知道辐射的类别 粒子的数量
we'd like to know the sorts of radiation, how many particles.
就要用上提姆·匹克任务中所用的探测仪
We're going to use the detector that is on Tim Peake's mission.
这是泰姆皮克斯探测仪 你来帮我启动
This is the Timepix detector. You're going to help me start it
走到前面去 来看看
so you're going to go round the front there and let's see
克鲁克斯先生笔记本的状态如何
how Mr Crookes' book does.
我要在这页纸上打开盖子
OK, I'm going to take off the cover now over that page.
每个小点代表一个粒子
So, every spot is a particle.
小点越大 粒子能量越高 开始了
The bigger the spot, the higher the energy. Here we go.
我们来"看一看"
Let's have a look
我们眼前的东西
at what we see.
笔记本突然...
The book has suddenly...
快看
Oh, here we go.
看啊
Here we go.
你们看见的这些小点
And so all of those dots that you can see there
都代表着穿过了探测仪的
are all particles of radiation or photons
放射性粒子或者具有能量的光子
of energy coming through that detector.
我觉得你们看得没有我们那么清楚
I don't think you can see it quite as well as we can see it here
塞莱斯特 粒子可真多啊 是不是
but, Celeste, that's a lot of particles, isn't it?
夏洛特 我不想再靠近这个笔记本了
Charlotte, I don't want to stand near this book any more
你还是拿走吧
so I think you should take it away.
塞莱斯特 现在让你回座位
Celeste, I think your mum would be really happy
你妈妈也会非常乐意的
if I sent you back to your seat as well.
非常感谢 塞莱斯特
Thank you very much, Celeste.
首先学到的是 不要吃含放射性的东西
So, lesson one is don't eat radioactive things,
我们从空间站得到了提姆·匹克使用的仪器
but we have some data from the space station,
所检测出的部分数据 就是这个
from the detectors that Tim Peake is using, and this is it.
为了让我们理解
And to help us understand
所阅图像 我想介绍
what we're looking at, I'd like to welcome
我的客人 太阳物理学家露西·格林教授
my guest, solar physicist Professor Lucie Green.
露西 这是什么 看着很令人担心啊
Lucie, what is that? It looks very worrying.
探测仪不仅向我们展示了辐射强度
That detector tells us not just how much radiation,
还有辐射类别 那这是哪种辐射呢
but the type, so what type of radiation is doing that?
探测仪能收集来自银河系各处
So, this detector's able to pick up electrons, protons and also
几乎是以光速飞行的
heavy atomic nuclei that come streaking in
电子 光子
from all over our galaxy,
及重原子核
travelling at almost the speed of light.
听起来有些凶险
Sounds slightly nasty.
在地球上我们不必担心那些物质
We don't have to worry about those so much here on Earth.
这里有台设备来向我们解释
You've got something here to explain that to us.
没错 这台装置叫做特雷拉机
That's right, so this is a set-up called a Planeterrella
它可以很好地同时演示两个事实
and it's a really nice way to demonstrate both the fact
即地球有磁场
that the Earth has a magnetic field
磁场引导带电粒子的活动
which guides electrically charged particles
以及带电粒子
and also the effect of electrically charged particles
对于地球大气的影响
on the Earth's atmosphere.
我们将要看到的是
And what's happening in here
电子 带电粒子
is that electrons, charged particles,
通过一个不可见的磁场加速
are being accelerated through an invisible magnetic field,
你们可以看到那个小球周围的亮光
and you can see that's around that small sphere, glowing lights.
那亮光就等同于北极光
And that's equivalent to the Northern Lights
和南极光 即极光
and the Southern Lights, the aurora.
从这里看也非常非常漂亮
It's very, very beautiful even here,
但观看极光还有一种更美的方式
but there is a more beautiful way of seeing this
那就是在太空中观看 我想我们有一些
and that's to be in space, and I think we've got some video
从太空拍摄的北极光的视频
of the Northern Lights as seen from space.
看那里
Look at that.
顶部的那缕绿光 就是北极光
That green glow in the top, that's the Northern Lights,
这是从空间站俯瞰的画面
and this is from the space station looking down.
这景象真是叹为观止
It's such a fantastic view.
宇航员有观看北极光的最佳视角
The astronauts have the best view of the Northern Lights.
我很嫉妒他们能看到这样的景象
I'm so envious of what they get to see.
可以看到薄薄的大气层 绿色发光的氧原子
You see the thin atmosphere, the green glowing oxygen.
对我们来说 这个覆盖层非常的重要
But for us, it's incredibly important, cos it acts as a blanket
它阻隔了我们早先看到的那些
to block out the effects of those
来自银河系的带电粒子的影响
galactic charged particles that we saw earlier on.
因此 当我们被地球磁场覆盖时
So, we can protect ourselves from some of the most harmful radiation
可以避开最有害辐射的影响
by sitting inside our blanket of magnetic field,
那我们继续探索太空是否安全呢
so are we all right to keep carrying on exploring?
我们需要克服一些困难
Well, there are difficulties that we have to overcome,
一些相当严峻的困难
really severe difficulties.
那么 我们谈论了来自银河的粒子
So, we've talked about particles coming from the galaxy
以及地球具有磁场
and the fact the Earth has a magnetic field
和大气层的事实
and an atmosphere.
对于这些来自银河的粒子
There is some protection from these galactic particles
太阳同样给了我们一些保护
that we get from the sun as well
我们发现粒子数量因太阳活动周期而不断变化
and we see that the number varies across the solar cycle.
太阳的磁场延伸并包围着地球
The sun's magnetic field extends out and surrounds the Earth
它为我们抵挡了银河中的宇宙射线
and it deflects the galactic cosmic rays from us.
但太阳亦敌亦友
But the sun is both our friend and our foe
太阳本身就是个惊人的粒子加速器
and the sun itself is an amazing particle accelerator
它同样能使诸如电子
and it's able to produce events where particles like electrons
质子之类的粒子在加速到几近光速
and protons get accelerated almost to the speed of light as well,
并且洒落在地球上
and they shower down on the Earth.
由于这些来自银河的粒子具有非常高的能量
So whereas the particles coming from the galaxy have very high energies,
它们形成了一种背景辐射
they form a sort of background radiation.
太阳产生的这些非常强烈的高通量爆发
The sun is capable of these very strong high-flux bursts
对于宇航员十分危险
and they can be very, very dangerous for astronauts.
我会给你们一些
And I'll give you a bit of information
有关太阳风中正常径流粒子的资料
about the normal flow of particles in the solar wind.
太阳时刻都有粒子流
So, the sun all the time has a flow
它们会花费几天 大概四天
that takes a few days, maybe four days, to get from the sun,
穿越一亿五千万千米的太空 来到地球
through 150 million kilometres of space, to us.
当高能粒子事件发生时
When an energetic particle event happens,
粒子半小时内就能抵达地球
they get here within half an hour.
风暴能持续数日
And the storm can go on for days.
很多粒子会照射到宇航员身上
And there are so many of them pouring down onto the astronauts.
一旦处于地球大气层外
Once you're above the Earth's atmosphere and the edges
地磁场的边缘外 你得到的保护就微乎其微了
of the Earth's magnetic field, you have very little protection.
事实上 这些粒子太过高能
In fact, the particles are so energetic,
它们甚至不管我们的磁场
they don't even see our magnetic field,
直接冲进来
they just come rushing in.
那么如果你是宇航员
And so if you're an astronaut
在磁场的保护之外