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高尔夫球上的坑,小身材大用途 – 译学馆
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高尔夫球上的坑,小身材大用途

Why Do Golf Balls Have Dimples?

运动中会用到各式大小 形状及不同设计的球
There are all kinds of balls used in sports, with different sizes, shapes, and designs,
这取决于运动的要求和历史
depending on the sport’s needs and history.
但高尔夫球比较奇特的是 它们的球面布满凹痕
But there’s something especially weird about golf balls: their dimples.
标准的高尔夫球有超过三百个凹痕
There are more than 300 dimples on a standard golf ball
这些凹痕不仅是为了美感
and they’re there for more than just aesthetics.
有凹痕的高尔夫球能比表面平滑的飞出近两倍远
Dimpled golf balls can fly almost twice as far as they would if they were smooth.
十九世纪中期,运动员注意到
In the mid-19th century, players noticed
破旧的高尔夫球比新的 抛光的飞得更远
that old-scratched up golf balls flew farther than new, polished spheres.
所以 他们为了让高尔夫球飞得更远 就在球上刻满凹痕
So they started carving grooves into their golf balls to make them fly better.
到1930年 经过几年的实验与误差测试
By 1930, after years of trial and error testing
高尔夫球演变为 今天我们所熟悉的有凹痕的球
the golf ball had evolved into the familiar dimpled shape we know today.
表面粗糙的高尔夫球飞得更远 这听起来很奇怪
It might seem kind of strange that a rough surface would make golf balls fly better,
那时候 他们并不知道这样做为什么会奏效
and at the time, they didn’t know why it worked.
但却知道 这样确实管用
They just knew that it did.
但如今我们知道 凹痕的作用在于“权衡”
But these days, we know the dimples work because of a trade-off
即 增大一种空气阻力 导致另一种空气阻力减小
increasing one type of air-resistance leads to a huge decrease in another.
有两种主要的空气阻力 表面摩擦和压差阻力
There are two main kinds of air resistance: surface friction and pressure drag.
表面摩擦的作用原理很像固体间的摩擦
Surface friction works a lot like friction between solid objects — air rubs against
空气摩擦作用于物体的侧面 从而使物体慢下来
the sides of an object, slowing it down.
一般来说 物体的表面积越大 其表面摩擦也越大
Generally, the more surface area something has, the more surface friction it creates,
所以 表面粗糙的高尔夫球会增大表面摩擦
so giving a golf ball a rough surface does increase surface friction.
但这同时也影响了第二种空气阻力 压差阻力
But it also affects the second kind of air-resistance: pressure drag.
球飞起来时 会把空气推开 并在其背面形成尾迹
As the ball flies, it pushes air out of the way, creating a wake
一个圆锥形的低压区
a cone-shaped pocket of low pressure behind the ball
(该低压区)把球向后吸 并使其慢下来
which sucks it backward and slows it down.
用手以不同的角度划水 你就可以感受到尾迹了
You can experiment with wakes if you paddle your hand through water at different angles.
用手掌划水 就会在手的后方看到一个三角形的尾迹
If you lead with your palm, you’ll see a big triangular wake behind your hand, and
你会注意到你的手在水里很难快速移动
you’ll notice that it becomes much more difficult to move your hand through the water at higher speeds.
但如果你侧着手划水 尾迹就会变得很小
But if you turn your hand sideways, the wake becomes much smaller, and your hand passes
你的手也就可以更容易的划水了
through the water much more easily.
在高尔夫球中
In a golf ball
凹痕通过产生所谓的湍流边界层来减小尾迹的大小
dimples reduce the size of the wake by creating a layer of what’s called turbulent flow.
粗糙的表面破坏了球周围空气的平滑路径
The uneven surface messes up the smooth path of air around the ball, making it much harder
这让尾迹很难形成一个完整的圆锥形(低压区)
for the wake to form into a clean cone.
鉴于尾迹的变小 粗糙的高尔夫球不再被向后吸
With its smaller wake, a dimpled golf ball doesn’t get sucked backward as much, so
所以它可以飞得更远
it flies farther.
高尔夫球用凹痕来搅乱球周围的空气从而使尾迹迅速消失
So, golf balls have dimples to mix up the air around the ball causing the wake to collapse
这让球飞得更快更远
more quickly, which allows the ball to fly faster for longer.
当然 文化也是这种平衡中的重要部分
Of course, culture is a big part of the equation too.
受这一作用的启发 网球变成了这样毛绒绒的如果有凹痕的话 橄榄球也会做的更好
Tennisballs get this effect by being fuzzy and Footballs would do better with dimples,
但目前只能勉强接受系带的了
but have to settle for laces.
谢谢大家的提问并特别感谢Patreon上
Thanks for asking, and thanks especially to all of our patrons on Patreon who keep these
所有回答问题的老主顾们
answers coming.
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like access to an exclusive monthly livestream, just go to patreon.com/scishow.
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视频概述

高尔夫球运动是项高雅运动,在绿草如茵的场地上,轻轻挥动球杆,本身就是一种享受。但细心的人会发现,高尔夫球与普通的球有些差别,差别就在高尔夫球的表面。

听录译者

收集自网络

翻译译者

稀甜稀甜的焦糖玛奇朵

审核员

启点—飞雪群山

视频来源

https://www.youtube.com/watch?v=2B_bkDOnwJY

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