英国皇家科学院圣诞讲座：如何在太空中生存（2015）

很好
Very impressive.
看 我说要把你们变成火箭发射器的
Look, I told you I'd turn you into rocket launchers,
你们可能会期待它们能进入轨道
and you may have expected those to go into orbit.
它们正在努力进入轨道
They were trying to go into orbit.
你扔出去的每一样东西
Everything you throw,
其实都想要进入一个轨道
as it turns out, wants to go into an orbit.
只是地球挡住了它们
It's just that the Earth gets in the way.
当你扔出袋子的时候 亚当
Now, when you threw your bag, Adam,
它落到了这里
it came and it landed here.
弗莱德 当你更加用力扔你的袋子时
Fred, when you threw yours a little bit harder,
弧线较缓 走得更远 最后落到这里
shallower arc, further, and landed here.
它们本应该进入
So it would have gone in orbit
围绕着地球质心的轨道运行
around the centre of mass of the Earth
但地球挡住了它们的路
but the Earth just got in the way.
这是有人在很久之前就发现的一件事
And this is something that someone realised a long time ago.
弗莱德 亚当 非常感谢
Fred, Adam, thank you so much,
请你们回到座位上去吧
why don't you go back to your seats?
科学家们在三百多年前就发现
So what scientists realised more than 300 years ago,
这其中有一位科学家尤为重要
and one scientist in particular,
如果你足够用力地去扔一个物体
was that if you could throw something hard enough
它就会沿着一个足够长且浅的弧线
it would travel in a long enough and shallow enough arc
一直下落 却永远不会落向地面
that it would fall and never again hit the planet.
它会一直绕着地球下落
And it would fall forever around the Earth,
这就是轨道
and that's what an orbit is.
如果你用别的东西来代替你的胳膊
If you take something, instead of your arm,
比如用一门加农炮
you take a cannon,
就像图上的这个
as we have in this diagram here,
你可以想象那是亚当扔出去的
you can imagine that might have been Adam's throw,
那个是弗莱德扔出去的
that might have been Fred's throw,
那是一个合适的火箭发射器
and that is a proper rocket launcher
一路搭载你绕着地球然后进入轨道
getting you all the way around the Earth and into orbit.
对我来说 这一切都很不可思议
Er, and it's incredible, I think, to me,
三百多年前
that more than three centuries ago
有一名科学家就已经得到了
a scientist could have had the kernel of thought
在好几个世纪后将人类及物体
that would get people and objects into space
送入太空的核心思想
so many, many centuries later.
当然那位科学家就是艾萨克·牛顿爵士
That scientist, of course, was Sir Isaac Newton,
我们也清楚他的想法
and we know what he thought
毕竟他都将想法写在了一本书里
cos he wrote that stuff down in a book -
可能是最重要的
possibly the most important,
至少是科学史上
or at least one of the most important,
最重要著作之一
books in the history of science.
其名为《自然哲学的数学原理》
And that book was called Principia.
"原理"正是提姆任务的名字
Principia, with no coincidence, is the name of Tim's mission.
这是他在本次任务期间
This is the patch he wears on him
一直佩戴的臂章
at all times during this mission,
名字出自这部重要的著作
and it's named after that very important book.
今天在皇家科学院的各位十分幸运
And we here are the Royal Institution are extraordinarily lucky,
因为我们保存有这部著作相当早的版本
because we have one of the very early editions of that book,
帮助我向你们展示这本书的是
and to help me show it to you,
向各位介绍我们的馆长 夏洛特
I'd like to introduce our curator, Charlotte.
夏洛特 这本书有多老了
Now, Charlotte this is how old, this book?
1713年出版
Er, 1713.
这本《自然哲学的数学原理》出版于1713年
It comes back to 1713, and this is Principia,
这是第二版吗
it's a second edition...?
-第二版 -在这本书
- Second edition. - Of that textbook.
牛顿在这本书里陈述了他的想法
So this is Newton laying down his thoughts about
关于万事万物运作的方式
how people and objects in the world behave
以及运动定律
and the laws of motion,
运动定律
请走近一点
and if you just come in here,
菲尔 拍一下这里 这是书中的一页
Phil, and take a look at this, this is a page from that book.
我得洗个手
I have to wash my hands
再来拿这本书 不然会弄坏它的
before I touch it otherwise I'll damage it.
-我能拿吗 -能
- May I take it? - Yes.
真是漂亮
It is very beautiful,
能看到这本书 我们真是万分荣幸
and we're very privileged to have it.
你们可以看见
And if you can see there,
这本书的书写语言不是英语
it is written in a language other than English.
这是拉丁语 当时所有学术性文章
This is Latin, as all academic texts
都使用拉丁语
of the time were written.
我完全不会拉丁语
And I don't speak any Latin,
但我得到可靠消息说这一页
but I am reliably informed that this page
讲的是运动三定律
is the three laws of motion.
请看这里的"法则三"
And if you take your eyes down here to Lex III,
或"法则3"
or Lex Tres,
这就是牛顿第三运动定律
that is Newton's Third Law of Motion.
想必大家在学校都认真听讲了
And I know, because you all pay attention at school,
一定知道牛顿第三运动定律指
that you know that Newton's Third Law of Motion is...
每一个作用力都会产生一个大小相等的
For every action there is an equal...
反作用力
..And opposite reaction.
好了
Ok.
我一直都想做这件事
So, uh... I've always, always wanted to do that.
那样使用灭火器
That's possibly the only circumstance
估计只有在这里才可以
in which it's acceptable to use fire extinguishers in that way.
别学我 真的别学我
Don't do that. Really, don't.
好了 300多年前牛顿告诉我们
Um, so! Newton told us over 300 years ago
如果想进入太空 我们需要
that what we need to do if we want to go into space
一 非常用力地抛出物体
is one, throw something really, really hard,
二 朝那边抛出物体
and two, throw something that way
就能让你的运载飞船和船员
so you can propel your vehicle
朝相反方向运动
and your crew in that direction.
现在的问题是 你要抛出什么呢
And the question here is, what is it that you throw?
答案就是火箭燃料
And the answer is fuel out of a rocket.
火箭燃料极其危险
Er, and rocket fuel is extraordinarily dangerous,
但我们设法拿到了一些
but we've managed to get some.
这是火箭燃料 货真价实的
This is rocket fuel, this is real rocket fuel,
非常易燃易爆
and it's pretty explosive.
赶快闻一闻
Have a quick smell of that.
火箭燃料
Rocket fuel.
火箭燃料 闻一闻
Rocket fuel. Have a smell.
非常非常危险的火箭燃料
OK, so very, very dangerous, rocket fuel.
这种物质由碳原子和氢原子组成的长链
So this stuff, long chains of carbon atoms and hydrogen joined together,
而火箭燃料就是依靠
and the energy between those bonds you let go -
长链断开时释放出的能量
oh, yes - before you make it become the stuff
将人类及物体送入太空
that sends people and objects into space.
火箭燃料这种物质
Rocket fuel is the sort of stuff that, you know,
出岔子时
if you're around when it goes wrong,
你绝不会想在旁边
you tend to not be around for much longer.
可以了吗
So...you all right?
准备好了吗 开始吧
Ready? Here we go.
最好还是先把这弄灭
Better stamp that one out.
好了好了 我们再来一次
OK, OK, OK. We'll go again,
再来一次 再来一次
we'll go again, we'll go again.
好 开始了
OK, OK, OK, here we go.
好了 我当然乐意那么做
All right, so of course, I was happy to do that,
因为这种燃料 在当前条件下
because of course, this stuff is engineered to be safe
被设计为安全的
under these circumstances.
火箭燃料需要这样
That's what you want out of your rocket fuel.
这对提姆在太空中生存至关重要
That's a very vital part of Tim's survival in space.
我们希望火箭燃料
This is what you want rocket fuel to do -
在作为燃料点燃
you want it to be safe on the pad under these conditions,
以及释放出所有能量之前
before you light it, and let it be everything it can be,
在发射台上是安全的
before you let it liberate all of its energy.
燃料经过专门设计来达到此目的
And it is engineered very specifically to do that.
将煤油进行精炼
They take kerosene, they refine it very carefully,
剔除掉一些轻质馏分
they take out some of the lighter fractions,
即部分短链分子
so some of the shorter chain molecules,
这样燃料就不易燃
so it's not so volatile,
所以我无法那样将它点燃
which means that I can't get it going like that.
现在的问题是 我要怎样才能