1974年一列法国列车的时速打破了速度记录
In 1974, a French train smashes through a speed record,
超过250英里每小时
exceeding 250 miles per hour.
但这列火车并不像之前的那样
But this train is unlike any other beforeit.
它没有轮子
It doesn’t have wheels.
由于悬浮在空气轨道上，因此他可以高速高效运行
It hovers on a cushion of air, and because of that, it can travel efficiently at very high speed
也许你从为听说磁悬浮列车
Maybe you ’ ve never heard of hovertrains,
但二十世纪七十年代 已经有人尝试去解决列车速度慢
but by the 1970 ’ s, they were seriously being
和一些国家铁路破旧严重等问题
considered as the solution to slow, antiquatedrailways which in many countries were in
因此20世纪60年代铁路处在麻烦中
In the 1960’s, railways were in trouble.
在发达国家公共交通乘客人数骤然下降 火车乘坐人数当然也处于下降趋势
In developed countries, ridership was plummetingand railways were in decline.
在英国 一些路线仍然在使用蒸汽列车
In Britain, some routes were still servedby steam locomotives.
然而 公众逐渐开始把到列车作为慢的和过时的
And the public was beginning to view rail as slow and outdated.
如今火车不得不与新兴的高速交通工具和城市飞行工具做竞争
Trains now had to compete with newly built superhighways and intercity air travel.
日本甚至最先造出了新的高速列车
And even Japan ’ s newly introduced Bullet Train,
在1964年 这项技术奉为传奇
a technical marvel for 1964, was initially
每小时的时速就可以高达130英里
only running at speeds of up to 130 milesan hour.
然而 部分问题是运行线路
Part of the problem was most rail lines
在发达国家被创建早了半个世纪
in the developed world, were built a half century earlier,
他们有完美的曲线，
with their sharp twists and curves,
他们不仅仅为了速度而建。
they just weren’t built for speed.
但是这些列车也有一些问题。
But the trains also had a problem.
他们的轮子必须造成特定的形状。
And it had to do with the shape of their wheels.
他们轮子不是完美的圆柱形而是圆锥型的。
Train wheels are not perfectly cylindrical,they’re cone-like in shape.
这个能使他们能在轨道上，特别是曲线弯道上。
And this is what keeps them on their track, especially around curves.
尽管车轮有轮缘，
While the wheels also have flanges,
这些其实是作为一个保险
these are really just a backup in case limits of
以限制园锥车轮超速。
that conical shape are exceed.
圆锥型车轮是一个伟大的创新
The conical shape of train wheels is a brilliantinnovation.
但他有一个震荡的问题
But there’s a problem, and it’s called HuntingOscillation.
以高速行驶的话
At higher speeds,
车轮从一边到另一边会越来越摇晃
the cone-like shape causes a train to increasingly rock from side to side.
凸缘会撞到轨道
The flanges start hitting the track,
会增加阻力是速度无法进一步提升
which increases resistance, making higher speeds
导致磨损和损坏
inefficient and causing wear and damage.
如果速度足够
Given enough speed,
震荡作用甚至会造成列车自行脱轨，
Hunting Oscillation can even cause a train to derail itself, on a
即使是在相当笔直的轨道上。
perfectly straight track.
这意味着从火车从本质上就会有速度限制
This meant that trains essentially had a speed limit built right
而这源自于列车的设计基础。
into their basic design.
所以，到了二十世纪九十年代，
So in the 1960 ’ s,
就有人思考也许是时候把火车的轮子给去掉了。
the thinking was that maybe it was time to get rid of wheels all together.
法国人已经修建起悬浮列车。
The French have already built the Aerotrain.
通过去除车轮得设计方法，
Designed to reduce the running
来降低有轮列车的运行时的摩擦问题。
friction problems of wheeled trains by doing away with the wheels.
这就是所谓的悬浮列车。
It’s called a hovertrain.
将高压空气压入托举气垫，
By feeding high pressure air through lifting pads,
列车将会悬浮在气垫上，
the train would float on a cushion of
这非常像气垫船。
air much like a hovercraft.
这种列车的轨道仅仅起到导向作用。
The track would act merely as a guideway.
没有车轮的滚动摩擦，
Without the rolling resistance of wheels,
悬浮列车意味着高效
a hovertrain promised efficiency and much
和更快的速度。
higher speeds.
主导这项目
And leading the way
提供技术支持的是一位名叫简.布丁的法国工程师。
for this promising technology was a French engineer named Jean Bertin.
在1973年，布丁带领他的团队
By 1973, Bertin and his team had
已经建造了一列能运载80个乘客的悬浮列车。
built a hovertrain that could carry 80 passengers.
法国官方以及媒体对列车的速度和良好的乘坐体验惊奇不已。
French officials and the media marveled at its combination of speed and smooth ride.
布丁称他的发明为高速悬浮列车。
Bertin called his designs Aerotrains.
经过几年不知疲倦的工作，布丁又研发出一系列相关车型，
Over the years, he had worked tirelessly to develop several prototypes,
进一步从理论上验证了
proving the viability
悬浮列车的可行性。
of the concept.
随着一系列的成功，他得到了政府基金的支持。
With each success, he secured a healthy doseof government funding.
最先进的悬浮列车是由涡轮发动机驱动。
The most advanced Aerotrain was powered bya turbofan.
这几乎和航空客机一样。
pretty much straight off an airliner.
这能提供一万二千磅的推力。
It produced over twelve thousand pounds ofthrust.
在前面，
At the front,
一台400马力的燃气涡轮提供高压气体
a 400 horse power gas-turbine supplied high-pressure air to hover this twenty
将这载重量20吨的列车抬离导轨四分之一英寸。
tonne loaded train a quarter of an inch offits guideway.
而导轨，由水泥浇筑而成。
And the guideway, was essentially poured concrete.
悬浮列车能轻而易举的在上面悬浮。
An Aerotrain could easily hover over imperfections.
这意味着悬浮列车的导轨
That meant that hovertrain lines were
比传统的铁轨更容易修建
potentially easier to build than conventional rail and
也更加便宜和容易维护。
cheaper to maintain.
在1974年3月5日，
On March 5, 1974,
一列悬浮列车证明了它能以接近260英里
an Aerotrain proved it could travel at nearly two hundred and sixty miles
每小时的速度行驶。
per hour.
并且它可能还能跑的更快，
And it might have gone even faster,
如果测试的轨道能更长的话。
had its test track had been longer.
布丁研发悬浮列车原型的成功
The success of Bertin ’ s prototypes led to plans
使悬浮列车线路链接整个法国的计划得以开展。
for Aerotrain links throughout France.
就在几个月后列车运行速度的记录就被打破了，
And just a couple months after the record breaking speed-run,
一个合同签定了
a contract was signed
开始建设最早的一条线路。
to begin construction of the very first line.
在法国以外，其他国家也对此关注。
Outside of France, the world was also takingnote.
英国，曾经发明了气垫船的国家，
The British, who had invented the hovercraft,
在开发悬浮列车技术上有巨大的
could see the enormous potential of hovertrain
潜能。
technology.
在1970年英国实施了他们自己的悬浮列车测试。
They constructed their own hovertrain testtrack in 1970.
在某些领域，
And in some ways,
英国在悬浮列车上的研究甚至是更加先进。
Britain ’ s research into hovertrains was even more advanced.
他们的原型车，RTV-31有轨气垫船围绕着另外一个重要发明展开设计。
Their prototype, the RTV-31 Tracked Hovercraft was designed around another important innovation.
线型感应发动机。
The Linear Induction Motor.
尽管布丁也尝试线型感应发动机的实验，
Although Bertin also experimented with Linear Induction Motors,
但他大多数的悬浮列车
most of his Aerotrains were
是靠叶轮或喷气推动。
fan or jet propelled.
但线型感应发动机更加高效。
But a Linear Induction Motor is more efficient.
替代传统发动机旋转式运动的方式，
Instead of the rotary movement of a conventional motor,
线型感应发动机提供线型推力
it provides a linear force for forward
运动。
movement.
不产生涡轮发动机在地面运行时的任何噪音或污染。
Without any of the noise or pollution of a turbofan running at ground level.
英国人的目标是建造一套运输
The British were aiming to build a transportation
系统，实现250英里
system that could travel at two hundred and
每小时的速度。
fifty miles per hour.
美国人，尽管没有什么优势但同样在进行悬浮列车技术的研究。
The Americans, not ones to be outdone were also researching hovertrain technologies.
在1965年，地面高速运输法案通过。
In 1965, the High Speed Ground TransportationAct was passed.
这对更高速的铁路引入美国起到了帮助作用。
It was an effort to introduce faster railto America.
开发新技术的基金到位
Funding was put towards developing new technologies and
甚至布丁的悬浮列车设计也被许可。
even licensing Bertin ’ s Aerotrain designs.
各式各样的悬浮列车原型被研制出来，
Various hovertrain prototypes were developed,
有些是用线型感应发动机，
some powered by Linear Induction Motors, others
有些是用喷气发动机。
by Jets.
但大部分研发的原型列车是城市有轨气垫列车。
But the most developed prototype was the Urban Tracked Air Cushion Vehicle.
同时有圆滑无窗的驾驶室设计和流线型样式，看起来就像跑的很快。
With its sleek windowless cockpit and Blade Runner styling, it certainly looks fast.
这被设计实用于
It was designed to operate
交通运输压力比较大的城市区域最高时速达到150
in heavily travelled urban areas and had a top speed of about 150
英里每小时。
miles per hour.
有轨气垫列车
The Tracked Air Cushion Vehicle was
的完全研发原型车经历了
a fully developed prototype that underwent regular
规范的轨道运行测试，在科罗拉多的蒲波地区。
testing on its track in Pueblo, Colorado.
在20世纪70年代初，
At the start of the 1970 ’ s,
气垫火车看着好像是准备了好对传统火车进行革命。
hovertrains looked poised to revolutionize rail.
但仅仅是几年之后，
But just a few years later,
没有一个国家在推行这项技术。
not a single country was pursuing the technology.
贯穿法国的气垫列车雄威计划也没有具体开展。
Ambitious plans for Aerotrain links throughoutFrance never materialized.
到今天还能看到的仅仅是当时测试的几条轨道。
All that’s left today are the abandonedtest tracks.
经历了20世纪70年代的全球大衰退
A global recession in the 1970 ’ s
迫使政府削减了雄威的运输改革项目
pressured governments to cut funding for ambitious transportation
经费。
projects.
造成许多重要的技术公关没有实际开展。
And some critical technical challenges werenever really worked out.
在高速状态，
At high speeds,
悬浮列车比传统火车更高效
hovertrains could travel more efficiently than conventional trains but at
但是在低速状态时，就不如传统火车了。
low speeds, they wouldn’t stand a chance.
但这不是悬浮列车失败的真正原因。
But that’s not really why they failed.
在20实际70年代，第一列磁悬浮列车就已经开发好了。
In the 1970’s, the first maglev train werealready in development.
它们使用电磁铁悬浮
They would use electromagnets to levitate
在导轨上而不是用高压气体
over a guideway instead hovering using high
悬浮。
pressure air.
磁悬浮列车相比与气垫列车更加高效和更快的速度。
And so Maglevs promised even greater efficiencyand speed over hovertrains.
但是磁悬浮列车同样也未能变革传统火车。
But Maglev’s also failed to revolutionizerail.
在接下来的40年里，
After nearly four decades,
只有屈指可数的磁悬浮列车在实际运行。
there ’ s only a handful of them operating in the world.
今下的高铁仍然大部分是以传统轮式火车为开发基础。
High speed rail today is still based largely on conventional wheeled trains.
这展现出来的问题是
It turns out that the problems
铁路的进步不是技术变革式的向前，
of railways were overcome not by one revolutionary leap forward,
只是原有基础上的向前提高。
but by incremental improvements.
现有的铁路网是区域上的轨道现代化
Existing rail networks were modernized with sections
这使得列车时速可以
of track that could handle higher
更快。
speeds.
新信号技术伴随着更先进的暂停技术而进步。
New signaling technologies were developedalong with more advanced suspensions.
高精度的轮子和列车轮子的偏航减震技术发展使得更小的车轮锥形角度成为可能。
Precision machined wheels and yaw dampers allowed for train wheels with less cone angle.
同时也减少了运行时的摆动问题。
And that reduced the hunting oscillation problem.
不同于气垫列车，
Instead of Aerotrains,
法国投资建设他们的高速TGV列车服务，
the French invested in their high speed TGV rail service, which
这就是当下常见的时速200英里每小时的列车。
today routinely travels at 200 miles per hour.
英国人用独特的办法
The British came up with unique solutions
来解决诸如倾斜过急弯
like a train that could tilt into corners
更高速过急转弯。
and take sharp curves more quickly.
而美国人，起码在起初，是被汽车拖了后腿。
The Americans, at least for the time being, mostly stuck with cars.
气垫列车或是磁悬浮列车还是类似的其他
Hovertrains or Maglevs or any other
铁路系统更本性的变革，必须与将近
radical alternative to rail has to compete with nearly
一百万英里的现有铁路线路进行挑战。
a million miles of rail line already in existence.
车站和基础建设在世界上各个城市附近建设。
With stations and infrastructure built-out in nearly every city in the world.
结果是，用新的创意来适应现有的世界
Turns out, it’s easier to adapt
比让世界来适应新的彻底变革
new ideas to the existing world than to have the world
更加容易。
adapt to radical new ideas.
这就是为什么在原基础上的改进经常笑到最后。尽管，
Which is why incremental improvements oftenwin out in the end. Although,
那时解决问题的新方法。
there’s a new solution in theworks.
列车在新式的轨道上运行。
A train runs in a new kind of track.
这实际上是简化的压力管，
It ’ s actually a reduced pressure-tube,
这样可以减少摩擦和空气阻力。
so there ’ s less friction and air resistance.
由线型感应发动机或是空气压缩机驱动。
Driven by linear induction motors and aircompressors.
这让列车时速超过700英里每小时成为可能。
It promises to travel at over 700 miles perhour.
管状轨道即能悬空安装也能埋在地下［能让噪音减弱］。
It’s tube-like tracks could suspended or underground [voice fades out].
在这个视频里我用了一些概念术语，
I used some conceptual terms in this video,
像摩擦，滚动阻力和电磁感应。
like friction, rolling resistance and magnetism.
这些都是基础概念，
These are foundational concepts,
这些都是理解机器怎么运行的重要概念，
the kind that is crucial to understanding how machines work,
不管是悬浮列车，或者是超音速喷气列车。
whether it’s a hovertrain, or supersonicjet.
但这是关于
But it ’ s one thing to be
熟记概念和规则，同时另外
made to memorize a concept and the formulas, and another to
是从直觉上理解正真的发展，
actually develop an intuitive understanding,
这会让你在现实社会中
one that ’ ll actually benefit you in the
得到实际的获益。
real world.
这就是我为什么喜欢杰出组织网站。
And that’s why I love Brilliant.org.
这不仅仅能是高效学习数学
It’snot only a highly effective way to learn math
和科学的渠道，同时这也很有乐趣。
and science, but also a lot of fun.
杰出组织网站能让你投身于
Brilliant gets you engaged
解决问题和学习怎么做，而不是
by letting you solve problems and learn through doing, instead
只会听讲座和记笔记。
of just listening to a lecture and jottingdown notes.
这也能强化你的推理能力，
They strengthen your reasoning,
创造力和解决问题的技巧，这些都是
creativity and problem solving skills, which are essential
日常生活的本质。
to everyday life.
这是一个非常棒的地方
A great place to start acquiring
可以获得解决物理理解力
the critical building blocks for understanding physics
就是“日常生活中的物理知识。”
is ‘Physics of the Everyday’.
马上访问杰出组织网站并且登陆。
Go to Brilliant.org/mustard and sign up toget started.
这样，最先登陆的200名访客将降低20%
And also, the first 200 will get 20 %
的高级会员年费
off the annual premium subscription for a fun and
获得一些有趣和很好的体验。
engaging experience.