Here’s hoping Humpty Dumpty reads the news. In research out today, scientists have apparently figured out the safest way to drop an egg without it breaking.
Researchers at MIT conducted the study, published Thursday in Communications Physics. After nearly 200 experiments, the team determined that dropping an egg horizontally is more likely to keep it intact than a vertical drop—completely contrary to folk wisdom.
MIT and many other schools regularly host an “egg drop challenge” for their students. The goal is simple enough: use some ingenuity and basic materials like toothpicks and twine to construct a contraption that will keep their eggs from breaking once dropped.
But according to study researcher and engineer Tal Cohen, both teachers and online sources will often also recommend that the egg stays vertical to further lower the risk of cracking. The underlying assumption behind this advice is that the egg’s vertical structure resembles an arch, and arches are very good at redistributing the loads of energy (or force) placed on them.
“After a number of times doing this competition, we started to question the common notion. We weren’t convinced that the static explanation, which applies to an arch, translates to the case of dynamic impact,” Cohen, an associate professor in the Sustainable Materials and Infrastructure department at MIT, told Gizmodo.
Cohen and her team took some of the eggs left behind at the end of a recent MIT challenge to test their hunch in the lab, but their initial experiments were inconclusive. So they decided to start a formal and more extensive project.
In total, they dropped 180 eggs either vertically or horizontally onto a hard surface. The eggs were dropped in rounds of 60 each at three different heights: 8, 9, and 10 millimeters (basically between 0.32 and 0.39 inches). And overall, the vertically dropped eggs fared worse. More than half of the vertical eggs broke when dropped 8 millimeters, for instance, compared to less than 10% of horizontal eggs. Further tests also showed that the horizontally dropped eggs could compress more before breaking than the vertically dropped ones.
The findings might not be world-changing, but they illustrate how our conventional wisdom can sometimes lead us astray, even the kind that’s taught in science classrooms.
“People tend to have better intuition for stiffness and strength, which are important in statics. It is common that they refer intuitively to the redistribution of a load along the arch. However, when dynamics are involved, toughness is also an important quantity,” Cohen said. “For example, consider two balls; one made of glass, and the other of rubber. The glass ball is stiffer and may have higher strength, but when dropped from a height, the glass ball is also more likely to break, while the rubber ball can deform to absorb the kinetic energy, without breaking.”
Cohen notes that there are plenty of things in both nature and engineering like eggs that have thin shells protecting their inner contents. So their research here could very well help “influence how people think about these structures as well,” she said.
Personally, I’m just glad I’ll have another reason to be mad at myself when I inevitably drop my next egg onto the kitchen floor while cooking—I should have remembered to keep it horizontal!
