Engineering, Analysis and Design

# How to break spaghetti into two pieces

A study conducted at MIT showed how to break a spaghetti in two pieces. The question, why spaghetti does not break into two, also interested the famous scientist Richard Feynman and the explanation was made in 2005. Mathematicians from MIT have shown how to break it in two pieces. The explanation may be important for the understanding of crack formation.

You have just come back to home from work and decided to cook very delicious spaghetti. Then, you realized that the length of the spaghetti is longer than the optimum height that must be to perfectly fit your famous Sheffield-made fork. Therefore, you wanted to split it into only two pieces and bent it at both ends. But wait! Something went wrong. You did not manage to split it into two pieces and had more than two fragments. Regardless of how many try you attempt, it will end in the same result. This was one of the unresolved questions until 2005.

Courtesy of Ronald Heisser and Vishal Patil/MIT

The question, why do spaghetti not break in half  when it is bent, was explained by French scientists Basile Audoly and Sebastien of the Universite Pierre et Marie Curie*. The explanation caused them to win 2006 Ig Nobel prize for physics. According to their theory, after release, the rod’s curvature initially increases near the just-released end. Then a wave travels along the pasta. The first break occurs somewhere along the rod when the curvature exceeds a critical limit. The shock of the initial break then causes more bending waves to travel along the two newly formed pieces of the spaghetti, where they locally increase the curvature further and cause more breaks, leading to a cascade of cracks. This is the case for not only for a dry spaghetti, but also any long, thin rod. The mystery was revealed but we had still known how to break into two pieces.

The apparatus to test spaghettis,Image Credit: MIT

### How to break into two pieces?

Recently, MIT mathematicians showed how to break a spaghetti into two pieces. In a paper published in the Proceedings of the National Academy of Sciences. researchers report that they have found a way to break spaghetti in two, by both bending and twisting the dry noodles**. They carried out experiments with hundreds of spaghetti sticks, bending and twisting them with an apparatus they built specifically for the task. The team found that if a stick is twisted past a certain critical degree, then slowly bent in half, it will, against all odds, break in two.

Courtesy of Ronald Heisser and Vishal Patil/MIT

The researchers say the results may have applications beyond culinary curiosities, such as enhancing the understanding of crack formation and how to control fractures in other rod-like materials such as multifiber structures, engineered nanotubes, or even microtubules in cells.

Well, life has full of mysteries. Even while you are eating your meal, you can come across one of them. Fortunately, we have mathematics and physics to deal with them.

Sources:

http://news.mit.edu/2018/mit-mathematicians-solve-age-old-spaghetti-mystery-0813
https://www.aps.org/newsroom/pressreleases/ig-nobel-2006.cfm
*Basile Audoly and Sebastien Neukirch “Fragmentation of rods by cascading cracks: why spaghetti do not break in half” Phys. Rev. Lett. 95, 095505 (2005)

**Ronald H. Heisser, Vishal P. Patil, Norbert Stoop, Emmanuel Villermaux, and Jörn Dunkel “Controlling fracture cascades through twisting and quenching” in Proceedings of the National Academy of Sciences Aug 2018

Cover Image Credit: iStockphoto