Two MIT students just solved Richard Feynman’s famed physics puzzle

Richard Feynman once asked a silly question. Two MIT students just answered it.

Here's a fun experiment to try. Go to your pantry and see if you have a box of spaghetti. If you do, take out a noodle. Grab both ends of it and bend it until it breaks in half. How many pieces did it break into? If you got two large pieces and at least one small piece you're not alone.



Richard Feynman, world-class physicist, bongo player, and writer of letters, once spent an evening trying to break spaghetti into two pieces by bending it at both ends. After hours spent in the kitchen and a great deal of pasta having been wasted, he and his friend Danny Hillis admitted defeat. Even worse, they had no solution for why the spaghetti always broke into at least three pieces.

But science loves a good challenge

The mystery remained unsolved until 2005, when French scientists Basile Audoly and Sebastien Neukirch won an Ig Nobel Prize, an award given to scientists for real work which is of a less serious nature than the discoveries that win Nobel prizes, for finally determining why this happens. Their paper describing the effect is wonderfully funny to read, as it takes such a banal issue so seriously.

They demonstrated that when a rod is bent past a certain point, such as when spaghetti is snapped in half by bending it at the ends, a "snapback effect" is created. This causes energy to reverberate from the initial break to other parts of the rod, often leading to a second break elsewhere.

While this settled the issue of why spaghetti noodles break into three or more pieces, it didn't establish if they always had to break this way. The question of if the snapback could be regulated remained unsettled.

Physicists, being themselves, immediately wanted to try and break pasta into two pieces using this info

Ronald Heisser and Vishal Patil, two graduate students currently at Cornell and MIT respectively, read about Feynman's night of noodle snapping in class and were inspired to try and find what could be done to make sure the pasta always broke in two.

By placing the noodles in a special machine built for the task and recording the bending with a high-powered camera, the young scientists were able to observe in extreme detail exactly what each change in their snapping method did to the pasta. After breaking more than 500 noodles, they found the solution.

(Courtesy of the researchers)

The apparatus the MIT researchers built specifically for the task of snapping hundreds of spaghetti sticks.

The spaghetti will break into two pieces if the snapback is properly dispersed through the noodle by twisting it while it is bent. The twist must be rather severe though, nearly 360°. The two ends of the noodle must then be bought together very slowly.

The twisting adds another wave of energy to the snapback, one which tends to make the noodle straighten out again. When both waves are going through the noodle at the same time, the most intense pressure on the noddle is reduced and the second fracture is prevented.

The results hold true for spaghetti noodles of different diameters, though the scientists note that other pasta noodles might act differently. Having solved the problem of how to properly break spaghetti, they plan to focus on linguine next.

What possible application could this have?

The snapback effect is not limited to uncooked pasta noodles and can be applied to rods of all sorts. The discovery of how to cleanly break them in two could be applied to future engineering projects.

Likewise, knowing how things fragment and fail is always handy to know when you're trying to build things. Carbon Nanotubes, super strong cylinders often hailed as the building material of the future, are also rods which can be better understood thanks to this odd experiment.

Sometimes big discoveries can be inspired by silly questions. If it hadn't been for Richard Feynman bending noodles seventy years ago, we wouldn't know what we know now about how energy is dispersed through rods and how to control their fracturing. While not all silly questions will lead to such a significant discovery, they can all help us learn.


Befriend your ideological opposite. It’s fun.

Step inside the unlikely friendship of a former ACLU president and an ultra-conservative Supreme Court Justice.

Sponsored by Charles Koch Foundation
  • Former president of the ACLU Nadine Strossen and Supreme Court Justice Antonin Scalia were unlikely friends. They debated each other at events all over the world, and because of that developed a deep and rewarding friendship – despite their immense differences.
  • Scalia, a famous conservative, was invited to circles that were not his "home territory", such as the ACLU, to debate his views. Here, Strossen expresses her gratitude and respect for his commitment to the exchange of ideas.
  • "It's really sad that people seem to think that if you disagree with somebody on some issues you can't be mutually respectful, you can't enjoy each other's company, you can't learn from each other and grow in yourself," says Strossen.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less

3 ways to find a meaningful job, or find purpose in the job you already have

Learn how to redesign your job for maximum reward.

Videos
  • Broaching the question "What is my purpose?" is daunting – it's a grandiose idea, but research can make it a little more approachable if work is where you find your meaning. It turns out you can redesign your job to have maximum purpose.
  • There are 3 ways people find meaning at work, what Aaron Hurst calls the three elevations of impact. About a third of the population finds meaning at an individual level, from seeing the direct impact of their work on other people. Another third of people find their purpose at an organizational level. And the last third of people find meaning at a social level.
  • "What's interesting about these three elevations of impact is they enable us to find meaning in any job if we approach it the right way. And it shows how accessible purpose can be when we take responsibility for it in our work," says Hurst.
Keep reading Show less

Physicist advances a radical theory of gravity

Erik Verlinde has been compared to Einstein for completely rethinking the nature of gravity.

Photo by Willeke Duijvekam
Surprising Science
  • The Dutch physicist Erik Verlinde's hypothesis describes gravity as an "emergent" force not fundamental.
  • The scientist thinks his ideas describe the universe better than existing models, without resorting to "dark matter".
  • While some question his previous papers, Verlinde is reworking his ideas as a full-fledged theory.
Keep reading Show less

UPS has been discreetly using self-driving trucks to deliver cargo

TuSimple, an autonomous trucking company, has also engaged in test programs with the United States Postal Service and Amazon.


PAUL RATJE / Contributor
Technology & Innovation
  • This week, UPS announced that it's working with autonomous trucking startup TuSimple on a pilot project to deliver cargo in Arizona using self-driving trucks.
  • UPS has also acquired a minority stake in TuSimple.
  • TuSimple hopes its trucks will be fully autonomous — without a human driver — by late 2020, though regulatory questions remain.
Keep reading Show less