# MIT researchers do the impossible, break piece of spaghetti into two pieces

## "You never get this second break when you twist hard enough," researcher Jörn Dunkel said.

A twist is the key to besting the spaghetti challenge. Photo by MIT

Aug. 14 (UPI) -- Are you up for the spaghetti challenge?

MIT researchers were. They did what most scientists thought was impossible. Scientists at the research university successfully broke a single strand of spaghetti into two pieces.

Famed physicist Richard Feynman first made the spaghetti challenge popular in the middle of the 20th century, after noticing that spaghetti always seemed to break into several small pieces. Feynman never figured out why, but scientists in France finally explained the phenomenon in 2005.

When slowly bent from each end, scientists showed spaghetti strands initially crack in the middle, where the bend is greatest. The break causes a vibrational wave that triggers additional fractures -- the "snap-back" effect.

The discovery explained why spaghetti always shatters into several small pieces, but scientists still wanted to know whether spaghetti could ever be broken into two pieces.

The latest experiments by MIT researchers prove the feat is possible.

Scientists showed it's possible to break a piece of spaghetti in two by twisting the pasta strand past a specific critical degree. One the pasta has been sufficiently twisted, a bending force can be applied, causing the strand to break into exactly two pieces.

Researchers accomplished the feat with the help of a special apparatus designed for the task of bending sticks of spaghetti. The scientists littered the lab floor with broken spaghetti before finally accomplishing the feat.

Scientists described their accomplishment in the journal PNAS.

The feat was made possible by advanced mathematical modeling. Using the formulas developed to describe the snap-back effect, scientists showed twisting triggers a similar reaction. When the strand breaks, the remaining two pieces still want to straighten, inspiring a snap-back wave, but the pieces also want to untwist.

Because the untwisting wave moves faster than the snap-back wave, it works to dissipate the energy of the snap-back vibration.

"Taken together, our experiments and theoretical results advance the general understanding of how twist affects fracture cascades," Jörn Dunkel, an associate professor of physical applied mathematics at MIT, told MIT News.

Scientists believe the discovery could help material scientists control for the fracturing patterns in other materials.

"It will be interesting to see whether and how twist could similarly be used to control the fracture dynamics of two-dimensional and three-dimensional materials," said Dunkel. "In any case, this has been a fun interdisciplinary project started and carried out by two brilliant and persistent students -- who probably don't want to see, break, or eat spaghetti for a while."