An intrepid undergrad led the way to understanding the physics of snapping strands of spaghetti.

一个勇于探索的大学生，开辟了一条求解意面的断裂原理的新思路。

播音撰文：卡伦·霍普金（Karen Hopkin）

翻译：陈美娟

Physicists concern themselves with problems that are profound. The origins of the universe, the nature of time, the composition of matter. And then, there’s spaghetti. A pasta problem has perplexed physicists as celebrated as Richard Feynman, and has even been awarded an Ig Nobel prize. At issue:

物理学家一般会关注深刻的命题。例如宇宙的起源，时间的本质，物质的构成，以及，意面！“意面问题”困住了一群像理查德·费曼（Richard Feynman）一样的著的名物理学家，该领域的研究成果甚至被评过搞笑诺贝尔奖（IgNoble Price）。

“Why spaghetti doesn’t break into two pieces. Why it breaks into three pieces or more.”

“为什么一根意面不能断成两段。为什么它只能断成三段以上。”

Ronald Heisser, now a grad student at Cornell, decided to explore the misbehavior of spaghetti for an undergraduate math course he took at MIT.

罗纳德·海瑟（Ronald Heisser）现在是康奈尔大学的一名研究生，他在麻省理工大学的一次本科数学上并决定研究意面这种“不听话”的表现。

Now, you may never have noticed it, but it’s nearly impossible to break a single, dry piece of spaghetti in half. Feynman allegedly noodled with the puzzle. And Heisser became similarly possessed.

你可能永远不会注意到这个现象，不过想要把一根干意面条折成一半几乎是不可能的。据说费曼一直纠结着这个谜，而海瑟也经历过相似的过程。

“I’m a little bit of a contrarian person. So I thought it would be fun to try and break it into two. ‘Cause no one said you couldn’t do that. They just said why it doesn’t break into two.”

“我是一个有点叛逆的人。我想，试着把面条折成两段会很好玩。因为没人说过你不能把意面折成两段。他们只是说为什么意面折不成两段。”

In fact, the French researchers who were awarded the Ig Nobel prize in 2006 found that when spaghetti is bent evenly from both ends it will crack near the center, where the stick is most curved. But this initial break sets up a vibrational wave that quickly fractures the rod further. So you get multiple fragments.

事实上，2006年获得“搞笑诺贝尔奖”的法国研究者发现，将意面从距离两端点相同的位置弯折的时候裂口离中心很近，此处面条达到最弯。但是折断之后引发的振动波迅速让断裂加剧。这就是最后你得到不止两截面条的原因。

What Heisser wondered was whether he could somehow get around this vibrational “snapback” effect. And he found you have to do the twist. Heisser built a device for torquing his pasta with precision and he observed the resulting fragmentation with a high-speed camera. He discovered that introducing a twist of around 360 degrees to the long strand allowed him to produce the desired single pair of pasta pieces.

海瑟想知道他是否能设法绕开这种震动“反弹”效应。而他发现必须要制造扭曲的状态才可以。海瑟制造了一个装置用来精确地扭转他的意大利面，并用高速摄影机观察由此产生的碎片。他发现当一长条意面扭转到360度时就能制造出他想要的单对意面段。

That’s where Vishal Patil, a grad student in mathematics at MIT, comes in:

这就是另一个麻省理工数学专业研究生维萨尔·帕蒂尔（Vishal Patil）加入的原因：

“So I first heard about this spaghetti problem from coauthors Ronald Heisser and Professor Jörn Dunkel when I first arrived at MIT…and after hearing about this problem, I became interested in developing mathematical models for the fracture of this elastic rod. And in particular, to see if using this model you could find out ways to control the fracture in the rod.”

“当我来到麻省第一次从合著者罗纳德·海瑟和约翰恩·邓克尔（Jörn Dunkel）教授那里听说这个意面问题的时候，我就对建造这种有弹性面条折断时的数学模型非常感兴趣，尤其是想利用这种模型找到控制折断它的方法。”

Controlling fractures is a big issue in materials science and could have applications in everything from the design of highways and bridges to the engineering of nanotubes.

在材料科学上，控制折断反应是一个大的课题，它有从高速公路设计到纳米管的各类工程上的广泛应用。

Patil’s modeling showed that twisting the spaghetti dampens the snapback effect. That’s because once the twisted stick is broken, it will try to unwind. This rapid unwinding creates a “twisting wave” that basically blocks the vibrational snapback wave, leaving the spaghetti in two clean pieces. The work is served up in the Proceedings of the National Academy of Sciences. [Ronald H. Heisser et al., Controlling fracture cascades through twisting and quenching]

帕蒂尔的模型显示，扭转意面能抑制回弹反应。这是因为一旦被扭转的面条破裂，它就会舒展开。这种迅速的舒展反应制造了能阻断振动回弹波的“扭转波”，因此让意面利落地断成两截。这项研究发表在《国家科学学报》上。

VP: “Although the project was a bit of fun I think it’s quite nice when you can find interesting physics and maths lurking behind everyday, mundane objects.”

维萨尔·帕蒂尔说：“尽管这个研究项目听着有点不正经，我觉得能从每天的日常生活中发现隐藏的物理和数学现象还是很棒的。”