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小实验:如何使光弯曲

How to Bend Light

Hi I’m Jared, welcome to Fun Science Demos.
大家好 我是Jared 欢迎来到《趣味科学演示》
You know, here at Fun Science Demos, we like to say that
你知道的 在《趣味科学演示》中 我们常说
science is at work all around us.
科学无处不在
You just have to slow down and take a closer look to find it.
你只要慢下脚步 仔细观察就能发现
Something as simple as a pencil, a glass of water,
一些简单事物 如一根铅笔 一杯水
has a lot of science in it.
都包含很多科学
Check this out.
我们一起来看看
I’m going to take the pencil, put it in the glass of water
我要把这根铅笔放进这杯水里
and take a closer look at what happens.
然后仔细瞧瞧会发生什么
So take a look at my glass and my pencil,
现在 看一下杯中的铅笔
it almost looks like the pencil’s cut in half.
看着像被折成了两半
So what’s going on?
到底发生了什么?
Well, science is going on!
原来 科学正在起作用!
The pencil hasn’t changed
铅笔并没有变化
So why does it look like it’s been broken in half?
但为什么它看上去像被折断了呢?
Well, first we have to figure out how we see things.
首先 我们要弄清 我们是如何看到物体的
Through science, we’ve discovered that we are able to see objects around us
通过科学 我们发现 我们能看到周围的物体
because light bounces off of those objects and goes into our eye.
是因为光照射到物体上 并反射进入人眼中
We see things because of light.
因为光 我们看到了物体
When light travels through air, it travels really, really fast
光在空气中传播时 速度非常非常快
but when light travels through something like water,
但当它在某些物体 比如水中传播时
that water actually slows the light down
水会使它速度变慢
and it does something to that light when it slows it down.
在减缓光速的同时 水也对光产生了作用
Well, through science we’ve discovered that
通过科学 我们发现
when light travels through water it gets slowed down
光在水中传播时速度减慢
and because it slows down it actually bends.
而因为速度减慢 它实际上弯曲了
That’s why this pencil seems to be broken.
这就是为什么铅笔看起来像是断的
So to take a closer look at the idea that
我们来仔细审视一下这个想法
light slows down and bends when it goes through water
光穿过水时 速度减慢并发生弯曲
Well, we got ourselves a bigger container of water
我们这儿有个更大的容器 里面装了水
and we’re going to let this pencil act like light.
我们用这支铅笔来模拟光的行动
We’re going to hold it above and drop the pencil.
我们把它举起来 在容器上方 扔下铅笔
We’re going to see how the pencil moves through the air
看看铅笔是如何在空气中运动的
and then how it moves throught the water
然后看看它又是如何在水中运动的
and see if there’s a difference between the two.
同时观察两者是否有所不同
So I’m standing up above our container
现在我站在容器上方
I’m going to drop the pencil straight
我会垂直地丟下铅笔
take a close look at how the pencil travels through the air
仔细观察铅笔如何在空气中运动
and then watch what it does when it hits the water.
然后观察它碰到水时 又是如何运动的
Here we go
现在我们开始
so as the pencil fell through the air it fell straight
当铅笔在空气中下落时 它是垂直下落的
and when it hit the water it slowed down
当碰到水时 其速度减慢
and when it slowed down the path of the pencil bent in the water
而当它减慢时 在水中下落的路径弯曲了
That’s exactly what light does
这正是光所做的事情
Next we’re actually going to try and show you light being bent
接下来 我们将尝试向你展示 光弯曲的现象
but to do that we need to use a special kind of light.
但是为了做到这一点 我们要用到一种特殊的光
Scientists call it a laser.
科学家们称其为激光
Remember that most light, like sunlight or light from light bulbs,
还记得最常见的光 比如阳光或者灯光吗
is scattered, scattered all around
它们都是分散的 无处不在
but this light is focused into a single beam
但激光是聚焦成一束的光
so it’s really important to never point this in your eye
所以要牢记的是 永远不要用它对着你的眼睛
because the light from this laser isn’t scattered
因为激光产生的光不是分散的
and it’s focused in a single beam.
而是聚焦成一束的
We can actually see its path if we shine it through the right material
如果我们把它照在合适的材料上 就可以真实的看到它的路径

and the right material happens to be lemon flavored jello.
而这合适的材料恰好是柠檬果冻
We are going to turn the lights off and zoom in
我们将关灯并放大镜头
and take a closer look
仔细观察
and see what happens to the path of this light in this laser
看一下激光的路线发生了什么变化
when we pass it through the lemon jello
当它穿过柠檬果冻时
So we’ve zoomed in.
我们放大了镜头
I have my laser. I have my lemon jell.
这是激光 这是柠檬果冻
Let’s see if we can see the path the light travels
我们来看看 是否可以看到光传播的路径
And you can see my red laser goes right through the jello
现在你可以看到红色激光穿过了柠檬果冻
Now let’s see if we can actually bend this light
现在看一下 这束激光是否弯曲了
because it slows down as it goes through the jello
因为它穿过果冻时速度变慢
and take a closer look
我们近距离看看
and see if we can get to see the light actually being bent
是否能看到光发生弯曲了
So we’ve zoomed in, and I have my laser,
我们放大了镜头 这是激光
and I have my dish of jello
这是一盘果冻
And now to show you the bending of that light
现在我就向你们展示光的弯曲
I’m going to first shoot the laser above the jello on a straight line
首先 我会朝果冻上面垂直照射激光
and hit somewhere around this arrow
照到这个箭头附近
Then I’m going to shine that laser through the jello
然后我会将激光穿过果冻
and that jello should slow that light down
果冻应该会使光变慢
and bend it and move it over somewhere around here
并发生弯曲 使光线照射到这附近
So here we go
现在我们开始吧
I’m going to shine the laser at the dot
我打开了激光照在这个点上
not through the jello
没有穿过果冻
Now I’m just going to drop it down through the jello
现在我把它往下移动 穿过果冻
and you can see it move over back and forth.
可以看到它来回移动
Through the jello, the light bends
穿过果冻 光线产生了弯曲
and now it’s hitting over here
然后它照到了这里
It’s hitting there in a straight line
它垂直地照到了这里
but when it goes through the jello, you can see it bending
但当它穿过果冻时 你可以看到它发生弯曲了
Its path bends and the light has actually moved over
它的路线弯曲了 实际上产生了移动
That’s exactly why the pencil seemed broken
这就是铅笔看起来像折了一样的原因
The water was bending the light by slowing it down
通过减缓光的速度 水使光产生了弯曲
As this light travels through the jello,
就像这束光线在穿过果冻时
it slows down and bends and gets moved over
速度减慢了 产生了弯曲并发生了移动
If we look even more carefully
如果我们看得更仔细一点
we’re going to notice there’s a whole lot of bending going on
我们将注意到 多处弯曲现象的产生
It gets bent once as it goes into the jello as I follow that line
当我沿着这条线进入果冻时 光线会弯曲
but then as it exits the jello it gets bent again
但是接下来 光线从果冻中出来 又一次弯曲了
That’s a lot of bending going on and that light is being bent
有大量的弯曲现象产生 而光线弯曲了
as it slows down as it travels through the jello
是因为它穿过果冻时速度减慢
Something as simple as a pencil and a glass of water
一支铅笔 一杯水 一些像这样的简单现象
can teach us an awful lot about the science behind light
可以教我们很多光学背后的科学知识
Science is all around us. Light is all around us.
科学无处不在 光无处不在
Sometimes we just need to stop and try to wonder why
有时我们只需要停下脚步 尝试思考背后的原因
If you wanna learn more about light check our links
如果你想学习更多关于光的知识 请查询我们的链接
Thanks for watch
多谢观看

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视频概述

铅笔为什么在水中看起来像被折断了一样?平常生活中也能学到的光学小知识。

听录译者

收集自网络

翻译译者

midorishen

审核员

审核员 V

视频来源

https://www.youtube.com/watch?v=cvrH6O_iDN4

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