英国皇家科学院圣诞讲座：让火花飞（2014）

我们喜欢尝试
We like just trying things.
-你试那个 -好的
- So you try that one. - Ok.
我来试这个
And I will try this one.
看到了吗
Now you see,
我们让灯转了起来
we are definitely moving it.
在切换这些灯
We are definitely switching that light.
如果我们转动得足够快
And maybe if we switched fast enough,
或许会看到一个画面
we might see an image.
我觉得我们转不了那么快
But I don't think we will be able to switch fast enough, aren't we?
我需要点其它的东西来帮忙
I think I will need something else to help me.
我需要一辆自行车来帮忙
I will need a bicycle to help me explain this.
非常感谢 查理
Thank you very much, Charlie.
真是个智能的"电脑"
You were an excellent computer!
我和查理刚才所谈到的
Now what Charlie and I were just talking about there,
非常快速地切换这些灯
about switching the light very very fast
这种现象叫做视觉暂留
is a phenomenon that is commonly called persistence of vision.
或闪光融合
Or flicker fusion.
我要用这辆自行车来解释这个现象
And I'm going to use this bike to help me explain.
我们可以看到 这辆自行车有点不同
Now you can see that this bike is slightly different -
后轮这里被改装了
the back wheel has been hacked here.
它的主人将后轮变成了一个屏幕
and basically the owner has turned the back wheel into a screen.
那么这里装有
So what we have are
一排小LED
a bunch of our LEDs,
也就是发光二极管
our light emitting diodes down here.
一个微型控制器
A little microcontroller,
也就是个小电脑
so a little computer in here.
我们在里面预装了
And we also just have a bit of software
一些软件
that's already been pre-loaded.
在后轮上我们一共装了三条这种装置
And we have three of these strips on our back wheel.
我知道你们在想什么
Now I know what you are thinking.
这肯定不够成为一个屏幕的对吧
Surely that's not enought to form a screen, is it?
我们想要看到一幅图像
We want to be able to see an image.
如果我慢慢转动这个轮子
So if I spin this wheel slowly,
我可以看到
I can see,
我正在进行某种信♥号♥♥输入
I am having some sort of input.
我在影响着它
I am affecting that.
我不知道前排的你们看到了什么
I don't know about you guys in the front there
但我还没有看到图像
but I'm not seeing an image yet.
你们呢 没有
Are you? No.
我觉得我转得还不够快
I don't think I'm going quite fast enough.
所以我觉得我们需要转得快一点
So I think we need to go a little bit faster.
我现在骑不了这辆自行车
Now I'm not going to get onto this bike,
但我的朋友安迪会来骑
but Andy, my friend is.
你好 安迪
So, hi Andy.
你先骑上去
Get yourself on there.
布拉德利·威金斯为英国著名自行车运动员
皇家科学院自己的布拉德利·威金斯
The Royal Institution's very own answer to Bradley Wiggins
要为我们骑车了
is going to ride for us.
看看我们能不能看到图像
and see if we can see an image.
快快骑起来 安迪
So, nice and fast, Andy.
好极了
Brilliant.
现在我们能看到什么了吗
Now can we see something?
我从这里可以看到一些东西
I can see something from here.
写了"圣诞讲座"
Says Christmas lectures.
你们能看到吗
Can we see it, yeah?
好极了
Brilliant.
这现象的原理是
So what's happening there is
所有的像素点不在同时发光
all of the pixels are not lit up at the same time,
但它们闪烁得非常快
but they flash so quickly,
好极了 还出现了一个灯泡
Oh brilliant, a light bulb as well.
而我们却感觉灯光是连续的
That we're getting that perception of continuous light.
所以看上去好像所有像素点都在同时发光
So it looks like all of them are lit up at the same time.
太棒了 非常感谢 安迪
That's brilliant, thank you very much, Andy.
通过轮流点亮小灯
So, by turning on the lights in turn,
我们成功创造出了静态图像的视觉效果
we've managed to create that illusion of a static image.
这就是LED屏幕的工作原理
And this is exactly how LED screens work.
从我们这里非常小的屏幕
From the very small screens that we have here,
到很大的屏幕
to the very large screens,
例如在伦敦电视塔顶的那块
screens like on top of the BT Tower, for example,
皇家科学院
它今晚也被我们控制了
which we've also taken over tonight.
太棒了 我们控制了整个伦敦的屏幕
This is great! We're taking over all the screens in London.
看上去所有的灯都亮着
Now, it looks like all of the lights are on here
科学与生活同在
才显示出美妙的圣诞信息
to display wonderful Christmas messages.
但其实只有一部分灯是点亮的
But actually only some of them are on.
我们感知到的是连续的灯光
But we're creating this perception of continuous light.
我们可以将刚刚学到的知识
But can we apply what we've just learned here
运用在摩天大楼上吗
to our skyscraper?
还是那个问题
I've still got that question:
该如何将整栋楼变成一块大屏幕呢
how do you turn a whole building into a screen?
幸好我们选楼选的好
Well, thankfully, we chose well with out building.
你们可以看到这栋楼是规整的长方形
So you can see our building is very rectangular.
它的窗户就跟像素点一样
So it has windows which are like pixels,
也就是我们的图像元素
so our picture elements.
这栋楼我们选了13层
And we have 13 floors,
每层有14个窗户
and 14 windows on each floor.
13乘14等于多少
So 13x14 is?
182.
我们当然都知道答案
We all knew that, of course we did.
我也确信家长们都知道
And all the parents knew it, I'm sure.
所以我们一共有182个像素点
So we have 182 pixels.
和这里的小屏幕一样
And like our small screen here,
我们需要很多灯
we need lots of lights.
我们还需要控制这些灯的方法
But we also need ways of controlling those lights,
控制它们的开关
of turning them on and off.
壳牌中心已经有很多灯了
Now, the Shell building already has lots of lights,
但它们都是分层控制的
but they are all controlled floor by floor.
而我们需要以窗户为单位进行控制
And we need to be able to control them window by window.
所以不巧的是 我们得从头来
So unfortunatly we have to start from scratch.
我们得在182扇窗户上
We have to put a lamp and a bulb
都装上灯座和灯泡
in each of our 182 windows.
它们都被运到了皇家科学院
And they are all delivered to right here at the RI.
我们可以看到
And we can see here -
182个盒子即182个灯座被送来了
182 boxes and 182 lamps being delivered.
所有人都去拿箱子
It took everybody to try in get all of these boxes
并开始拆箱拿出所有的灯座
and start unpacking all of our just simple lamps here.
现在我们还需要182个灯泡
But now we need 182 light bulbs.
让我们再回到斯万的白炽灯上
So, let's go back to Swan's incandescent light bulb.
我们能用它吗
Could we use these?
斯万发明的灯泡优点是
Now, the great thing about Swann's light bulb is
它们的工作原理很容易理解
it is really easy to see how these work.
看第一个灯泡
If we just take our first bulb here,
我们可以看到里面的钨丝
we can see just our normal tungsten filament inside,
我们使用金属钨
and the metal is tungsten
因为它的熔点非常高
because it has a very high melting point.
这点很重要
And that's important.
当我将这个灯泡通电
So, when I plug this bulb in,
我们可以看到的是
what we see is
电流通过灯泡里的金属丝
the current has been passed through the metal in our light bulb,
使其温度升高
and that heats up the metal,
并发光
which makes it glow.
这里的玻璃罩对灯泡其实很重要
The glass is actually quite important for our light bulbs here.
但别光听我的话
But don't just take my word for it.
如果我们将玻璃罩移除
If we remove our glass,
像这里的第二个灯泡一样
like we've done in our second bulb here,
你们觉得会发生什么呢
what do you think is going to happen?
拿掉玻璃后 它还能亮吗
Is this going to work when we remove the glass?
这个和旁边的灯泡完全一样
So it is exactly the same as this one.
我看到有人摇头了
A few shaking of heads.
有人点头吗
Anyone nodding their heads?
也有一些人点头了
A few nod their heads as well. OK,