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这个老水手的谜团可以帮助挽救游泳者 – 译学馆
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这个老水手的谜团可以帮助挽救游泳者

This Old Sailors’ Mystery Could Help Save Swimmers

This episode is sponsored by NordPass.
本视频由NordPass赞助播出
NordPass takes the stress out of remembering your passwords
NordPass不仅可以帮你缓解记住各种密码的压力
and provides secure accessto all your online accounts.
还提供安全可靠的方式登录各种账号
Head to Nordpass.com/SciShow to learn more.
更多详情请登录Nordpass.com或SciShow
Today, if you’ve got somewhere to go, you might hop in a car
现如今 出门都是坐车
or even take a plane
甚至是坐飞机
But for centuries, a boat was your fastest way of getting around.
但几百年间 船才是最快的出行工具
Except when it suddenly wasn’t
除了某些特殊的情况外
for thousands of years, sailors have been telling stories of
几千年来 水手之间流传着一个神秘的故事
a mysterious phenomenon called dead water
关于一种“死水”的奇怪的现象
that could stop a ship in its tracks.
它能让行驶中的船停下来
We now know that dead water is just, well, water
现在我们知道“死水”也只是水而已
and after all these years
多年之后
scientists finally understand why it used to mess with sailors
科学家们终于知道为何这会让水手们困惑了
and how it might still affect swimmers today.
并且为什么现在还会影响游泳者
Fridtjof Nansen, a Norweigian sailor and future Nobel Laureate
挪威的水手兼未来诺奖的获得者Fridtjof Nansen
coined the phrasedead water back in 1893
在1893年创造了死水这一词
but he wasn’t the first to get stuck in it.
但这并不表示他是第一个遇到这种情况的
Stories of ships moving under full power
关于全力行驶的船只
suddenly slowing or even totally stopping
突然减速甚至停下来的故事
date back to at least 600 B.C.E.
要追溯到至少公元前600年
Sailors over the years have tried all sorts of ways to escape
几年来 水手们想尽各种办法逃离
from pouring oil in front of the bow to shooting at the water
从在船头上淋上油去开路
and even banishing monks from their ships.
到甚至赶走船上的僧侣
But, most of the time, if you’re caught in dead water
但是 多数时候 如果到达这片死水水域
you’ve just got to wait it out
你也只能听天由命了
After this had happened many times
这样的现象多次发生之后
people started to notice that dead water was more
人们开始注意到死水水域十分的正常
common where it was cold.
尤其在温度比较低的时候
For instance, Nansen’s ship, Fram, was sailing north of Siberia
例如 Nansen的船Fram在他们驶向西伯利亚时
when it got stuck
就被困在死水水域
This incident helped point to what was really going on
这一事件也帮助弄明白到底发生了什么
Sailors were getting stuck in places where a layer of
水手们被困住的这片水域
cold freshwater was floating on top of the salty sea.
咸海水的上方漂流着一层低温的淡水
Like, maybe meltwater from a nearby glacier.
这淡水是来自于附近冰川融化的水
The two types of water act almost like totally separate fluids
此刻咸水和淡水就像两种不同的液体
and the boundary between them is a lot like the one
它们之间的分界线更像是
between the water and the air.
大海和天空的界线
And that can make things complicated.
这让事情变得复杂起来
In 1904, the oceanographer V. Walfrid Ekman
1904年 海洋学家V Walfrid Ekman
showed mathematically that when a boat runs
用数学的方式指出 当船只行驶到
into this two-layer system, it creates massive waves.
双层水域 就会形成大的海浪
But those waves aren’t at the surface where water meets air
与水和空气在面上形成的浪花不同
they’re at the boundary between saltwater and freshwater.
这是种咸水与淡水汇集处形成的海浪
Which is why, to a sailor, the surface of the water looks perfectly calm
这就是为什么水手们看到海平面如此的平静
Creating these waves takes a lot more energy than
形成这样的海浪需要的能量远远超过
just producing the normal wakes you’re used to seeing around boats
你在船边看到的普通浪花形成需要的能量
especially when the boat is moving slowly
尤其当船只缓慢行驶
close to the speed of the waves themselves.
且速度几乎和浪波动的速度一致时
Those underwater waves will steal the boat’s momentum
这些水下的浪就像会偷走船的动力一样
and slow it down in the water
慢慢让船停下来
And as long as those waves are there
只要这些海浪还在
the boat’s not going anywhere
船哪里也去不了
at least not fast
至少也快不到哪里去
Ships can only escape once those waves dissipate
只有在这些浪消失了船才能逃离
which usually happens when they run into the boat
而这只有浪进了船舱才会发生
Fortunately, if you’re traveling much faster than the underwater waves
幸运的是 如果船行驶的速度比浪波动的频率快
this effect is pretty irrelevant.
对船的影响就微乎其微了
You’ll just outrun the problem in the first place.
那你很快就能逃离这片水域了
So most modern ships don’t have to worry.
所以多数现代的船只是不需要去担心这个问题的
But there is another kind of slow-moving vessel
但仍有一种动作缓慢的“船”
that might still need to worry about dead water: you.
需要担心死水 那就是你
Among open-water swimmers
在开放水域畅游的游泳者间
there are surprising cases of well-trained athletes
惊奇的发现 仍有水性很好游泳选手
drowning of exhaustion in perfectly calm water
在相当平静的水域里因为筋疲力竭而溺水
and some researchers wondered
一些研究者猜想
if dead water could have anything to do with it.
是否有方法可以解答这一问题
In a 2009 study, scientists found that
2009年的一项科学研究发现
swimmers moving through water with a thin, cool upper layer
当游泳者游过稀薄且冷的上层水域时
lost up to 40% of their motion.
会消耗他们大约百分之四十的体力
There’s still work being done in this area
在这种水域里这一理论也同样有效
but it could help explain why even strong swimmers can
也帮助解答为何即使是强壮的游泳者
sometimes get trapped in calm water.
有时也会在平静的水域里陷入困境
So it’s something to keep in mind
这是一件需要时刻谨记的事
if you go for s swim
当你游泳时
and feel water layers of different temperatures
并且感觉水层之间温度不同
We asked an expert and, if you find yourself
我们咨询了一位专家 当你发现自己
trapped in such a situation
陷入这样的境地时
your best bet is probably to stay calm
你最好保持冷静
and use a slow, shallow stroke.
并且慢慢的轻轻的划水
And, you know, maybe don’t swim by any melting glaciers.
或是不要在任何有融化冰川水的水域游泳
Maybe you’re not a swimmer
你也许不擅长游泳
but you still keep getting stuck on simple things in life
但也可能被生活中的琐碎事物所困扰
like remembering your passwords
比如说记住一些密码
or pulling up your credit card details when you need them.
又或者是当你需要关于信用卡的一些详细信息
If that sounds like you
如果前面描述的就是你
you might be interested in using NordPass to make your life easier
那你可能需要Nordpass来帮助你简化你的生活
NordPass is a secure app and browser extension
Nordpass是一个安全可靠的软件及网站
that remembers your complex passwords and credit card details
可以记住你复杂的密码及信用卡详细信息
and lets you access them from anywhere
并让你随时随地都可以使用
so you can work and shop online with ease
这样你就可以在网上轻松工作和购物了
Like say you’re interested in buying SciShow’s
就比如说 你有兴趣从DFTBA.com
pin of the month from DFTBA.com
按月购买Scishow的账号
With NordPass
有了NordPass
you won’t need to enter your credit card information every month.
你就不需要每个月都输入你的信用卡信息
NordPass will also generate secure, complex passwords for you
Nordpass也会为你生成安全复杂的密码
so you don’t have to think about them
这样你就不用费时去考虑这些
It’ll even auto-fill your online forms to
同样NordPass也可以自动填写你的在线表格
save you the trouble of copy-pasting
你就可以省了复印 打印的麻烦
NordPass has native iOS and Android apps
Nordpass 同时具有苹果及安卓系统的软件
and you can add the NordPass extension to your browsers.
也可以保存Nordpass的网页版
With the premium plan, you can securely share your password
Nordpass本着提供优质服务的原则 你可以安全的输入密码
and use the service across 6 devices simultaneously.
并且可以同时在六台设备上使用这一服务
And right now you can get 50% off a two-year plan
现在加入可以获得两年的半价优惠
plus one additional month for free
外加一个月的免费使用期
when you go to nordpass.com/SciShow or use code SCISHOW.
只要你开始进入Nordpass. com或Scishow或者使用SCISHOW密码
[ ♪OUTRO ]
结尾部分 音乐

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视频概述

水手们如果脱离在海上的困境,我们又该如果脱离记住各种各样得密码和信息的困境呢

听录译者

收集自网络

翻译译者

Rachel

审核员

审核员 V

视频来源

https://www.youtube.com/watch?v=Wwoi2BUxvTs

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