Can You Break a Spaghetti Stick in Two? Probably Not, but These Mathematicians Can

Breaking spaghetti in two is all about how you twist it. Bodhi Peace/Wiki Commons

Have you ever tried the spaghetti challenge? It's a lesser-known party game, mostly played by physicists, that involves holding a spaghetti stick at both ends, bending it until it breaks, and trying to snap it into two. It sounds simple enough, but until now, no one has ever been able to actually pull it off. Spaghetti, when bent to break, always snaps into three or more fragments.

It's such a mysterious phenomenon that famed physicist Richard Feynman spent time tirelessly breaking apart sticks of spaghetti, looking for a theoretical explanation for it, to no avail. In fact, it wasn't until 2005 that physicists from France were able to finally develop a theory that works. It was such a challenge that their solution actually won the 2006 Ig Nobel Prize — yes, for figuring out the mechanics of why spaghetti sticks never break in halves.

So, problem solved. Spaghetti sticks can't break in two. Or can they?

Ronald Heisser and Vishal Patil, mathematics students at MIT, were sure there had to be a way. And with the help of an apparatus they built specifically for the task, on one fateful evening in 2015, the students quite possibly became the first people to ever crack the spaghetti challenge, reports

Their analysis of how to do it can now be found in a new paper in the Proceedings of the National Academy of Sciences.

It turns out that it's all about twisting the sticks as they are bent.

"They did some manual tests, tried various things, and came up with an idea that when he twisted the spaghetti really hard and brought the ends together, it seemed to work and it broke into two pieces," said co-author Jörn Dunkel, who was the students' professor at the time. "But you have to twist really strongly. And Ronald wanted to investigate more deeply."

That's when Heisser built the mechanical fracture device that would allow the students to truly test their methods. The device is capable of controllably twisting and bending spaghetti sticks with mathematical precision, while a high-speed camera records the fracture with incredible slow-motion detail.

What the students found was that if you can manage to bend the spaghetti at almost 360 degrees, and then slowly bring the two clamps together to bend it... (cue sounds of angels singing)... it breaks in two.

The trick is in how the twist affects the forces and waves propagating through a stick as it is bent. Basically, as the spaghetti snaps, the twist unwinds and helps to release energy from the stick that would otherwise force it to shatter into additional segments.

"Once it breaks, you still have a snap-back because the rod wants to be straight," explained Dunkel. "But it also doesn't want to be twisted."

And so, finally we can snap spaghetti into just two pieces. It's one small snap for man, but one giant break for ... well, actually, it's unclear exactly how these results might end up having real world applications outside of the spaghetti challenge. But the experiment helps to advance our general understanding of how twist affects fracture cascades in rod-like structures, and there's no telling what kind of engineering breakthroughs could eventually come from it.

For now, though, it's a very intricate way of impressing friends at your next dinner party.