科学美国人60秒 “灭霸响指”背后的物理原理(1)

（单词翻译）

This is Scientific American’s 60-Second Science. I’m Karen Hopkin.

这里是科学美国人——60秒科学系列，我是凯伦·霍普金。

Doing science isn’t easy.

做科学研究并不容易。

It takes an enormous amount of time and energy to collect and analyze¹ data.

收集和分析数据需要花费大量的时间和精力。

At least, that’s the way it usually works.

至少，科学研究通常是这样运作的。

This is one of those examples that we joke that we can snap our fingers and get data.

这是一个例子，我们开玩笑说，我们可以打个响指就能得到数据。

That’s because Saad Bhamla and his students just wrapped up a study of the physics of finger snapping.

这是因为萨阿德·巴姆拉和他的学生刚刚结束了一项关于打响指的物理研究。

They found that the right amount of friction² is key to a successful snap.

他们发现，适量的摩擦力是成功打响指的关键。

Their work appears in the Journal of the Royal Society Interface³.

他们的研究发表在《英国皇家学会界面杂志》上。

Bhamla’s lab at Georgia Tech focuses on ultrafast motion in nature.

巴姆拉在佐治亚理工学院的实验室专注于自然界中的超快运动。

Organisms can achieve really, really fast motions, and we are curious about how they’re able to do this and how we may extract those principles for perhaps synthetic⁴ systems.

有机体可以实现非常非常快的运动，我们很好奇它们是如何做到这一点的以及我们如何为合成系统提取这些原理。

Their science may be hard-core. But their lab meetings include time to be a bit more playful.

他们的科学可能是硬核的。但他们的实验室会议包括让他们玩得更开心的时间。

We have something called Super Happy Fun Time.

我们有一个叫做“超级欢乐时光”的会议。

And in this, we’ll talk about something typically nonscientific just to kind of defuse the situation after a typically intense scientific discussion that a student presents.

在这个会议中，我们将谈论一些具有代表性的非科学的东西，只是为了缓和一下学生在通常激烈的科学讨论之后的情况。

A couple years back, their talk turned to the movie Infinity⁵ Wars.

几年前，他们的话题转向电影《无尽之战》。

In the climax⁶ of this Avengers flick⁷, supervillain Thanos forever alters the Marvel⁸ Cinematic Universe with a snap of his massive, metal-clad fingers.

在这部《复仇者联盟》电影的高潮部分，超级反派萨诺斯用他巨大的、覆盖着金属的手指打了一个响声，永远改变了漫威电影宇宙。

But something about the scene left Bhamla scratching his head.

但现场的一些事情让巴姆拉摸不着头脑。

And I said, “You know what?

我说，“你知道吗？

I’m willing to make a bet that if you had metallic⁹ gauntlets like Thanos has, I would suspect that it’s actually very difficult to store energy in a controllable way.”

我敢打赌，如果你有像萨诺斯那样的金属手套，我会怀疑实际上很难以一种可控的方式储存能量。”

Energy that then has to get quickly released if you really want to snap.

如果你真的想打响指，那么这些能量就必须迅速释放出来。

So Raghav Acharya, a student in Bhamla’s lab, set up an experiment.

因此，巴姆拉实验室的学生拉格夫·阿查里亚进行了一项实验。

He put some reflective dots on his fingers so he could automatically track the finger movement when you take a side view video with a high-speed camera—just to be able to extract out the velocities¹⁰ and accelerations¹².

他在手指上放置了一些反光点，这样当你用高速摄像机拍摄侧视视频时，他就可以自动追踪手指的移动-只是为了能够提取出速度和加速度。

Because the first thing they wanted to know was: Just how fast is this jazzy hepcat gesture?

因为他们最想知道的是：这个爵士音乐迷手势到底有多快？

We discovered that the finger snap takes about seven milliseconds.

我们发现打响指大约需要7毫秒。

To put that into context, that’s 20 times faster than the blink of an eye.

相比之下，这比眨眼的速度快20倍。

A blink of an eye is glacially slow: it’s like about 150 milliseconds.

眨眼是极其缓慢的:大约150毫秒。

Even more impressive than its speed was its acceleration¹¹, which was three times faster than the throwing arm of a big-league baseball pitcher¹³.

比它的速度更令人印象深刻的是它的加速度，比一个大联盟棒球投手的手臂投球要快3倍。