原题:How GPS was invented?
作者:Raj Arjit 工程师、企业家
翻译:张一震
校对:丁礼元
题图:spaceflightnow.com
Story of how this beautiful thing came to the world!
这是一个伟大的发明诞生的故事!
It is 4th October, 1957 and Sputnik has just launched. We are in Laurel, Maryland, at the applied physics lab associated with Johns Hopkins University. It is Monday morning and news has broken about a satellite orbiting around the planet.
1957 年 10 月 4 日是 Sputnik(俄语: 人造卫星)一号发射的日子。当时我们在位于马里兰州 Laurel 市的约翰 · 霍普金斯大学应用物理实验室里。这是一个星期一的早晨,卫星绕地球旋转的消息不胫而走。
All the physics geeks are thinking, "Oh my gosh! This is incredible, I can't believe this has happened." And two of them, Guier and Weiffenbach are having a discussion with their colleagues at cafeteria table. One of them says,"Hey has anyone tried to listen to this thing? There is a man-made device in space that is obviously broadcasting some type of signal, probably we could hear it, if we tune in. Colleagues say, "Not tried, but seems an interesting idea".
所有的物理极客心里都在想「我的天!这太不可思议了,真想不到这样的事会成为现实。」其中就有两个人,叫做 Guier 和 Weiffenbach。他俩在餐桌上和同事讨论这件事。其中一人说「嘿,有人尝试收听它发出的信号吗?很明显位这个人造装置在太空中广播一些信号。如果我们调到适合的频率,也许能够听到这些信号。」同事们说「还没试过,但貌似是个有趣的想法。」
Now, Weiffenbach is an expert in microwave reception and has got a little antenna setup with an amplifier in his office. After working a few hours, they actually start picking up the signal, because the Soviet made Sputnik was very easy to track. It was up there at 20 MHz, so you could pick it up really easily (as they were afraid people might think it was a hoax).
如今,Weiffenbach 成为了微波接收领域的一位专家。在他的办公室里有一个带有放大器的小型天线装置。由于苏联产的 Sputnik 非常容易追踪,经过数小时的工作,他们真的开始收到信号。接收频率是20 MHz,所以你可以很容易地捕捉到。(但是他们担心人们会认为这是个玩笑。)
So these two guys are hearing to the signal and their colleagues start pouring in their room amazed with the work. "We are the first people in US to be listening to it. We should record it," says one of the colleagues. Immediately they start recording the "bleeps, bleeps" sound. Plus they start writing down the exact moment - date, time, when each bleeps occur. Now they get another idea, that by using the data and the Doppler effect they can measure the speed that the satellite is travelling.
当这两个家伙收听到了信号,他们的同事都蜂拥进他们的房间,为之惊叹。其中一个同事说「我们是美国第一个收听这个信号的人,我们应该把信号记录下来。」 很快他们开始记录这些哔哔声。还记录下这些哔哔声响的具体日期和时间。现在他们有了另外一个想法——利用记录的数据和多普勒效应能测量出卫星运动的速度。(科普:多普勒效应是波源和观察者有相对运动时,观察者接受到波的频率与波源发出的频率並不相同的现象。来自维基百科)
Tinkering more on this, they get another insight: by using the slope of the Doppler effect graph, they can find out at which points the satellite is closest to the antenna or farthest away. They start working hard and get permission to use the UNIVAC computer to do the calculations and after fewweeks, it turns out they have figured out the exact trajectory of the satellite.
再经过一番计算,他们有了另外一个想法:利用多普勒效应图的斜率,能找出卫星离天线最近和最远的位置。他们开始努力工作并获得了使用 UNIVAC 计算机做计算的许可;数周后,事实证明他们可以计算出卫星运动的准确轨迹。
Bill Guier (左), Frank T. McClure(中), and George Weiffenbach(右)
A couple of weeks later, their boss, Frank McClure, asks them, "Hey you guys, I need to ask something. You've figured out an unknown location of a satellite orbitting around, from a known location on the planet. Could you go the other way? Could you figure out an unknown location on ground if you knew the location of satellite?
几周之后,他们的老板 Frank McClure 询问他们说「嘿,我要问你们几个问题。你们已经根据地球上已知的地点计算出做旋转运动的卫星的位置。你们能不能换一个思路?如果你们知道了卫星的准确位置,可不可以据此计算出地面上点的位置?」
After a bit of check the guys Guier and Weiffenbach come back and say, "It'll be actually easier". And that's how GPS was born!
经过一系列的检测, Guier 和 Weiffenbach 报告「事实上,这实现起来更加简单!」以上就是GPS的诞生过程!
Source - Steven Johnson's Ted Talk: Where Good Ideas Come From.
参考资料:Steven Johnson 的 TED 演讲:Where Good Ideas Come From.
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