Challenging common notions on how eggs break and the role of strength versus toughness

Abstract

One experiment commonly used to teach young students about the response of structures to dynamic loading is the “egg drop challenge”, in which students design a device to protect an egg from cracking after a fall from a specified height. Relevant to this activity is the choice of orientation of the egg to decrease the probability of fracture. In this study, we contest the commonly held belief that an egg is strongest when dropped vertically on its end. Through hundreds of experiments and a set of static and dynamic simulations, we demonstrate a statistically significant decrease in the likelihood that an egg breaks when oriented horizontally as opposed to vertically, and offer a concrete and intuitive explanation as to why this is the case. These results and the associated analysis demonstrate the importance of specificity of language and the dangers of appealing to “common sense” in the physics classroom while having wide-ranging implications due to the ubiquity of shell structures in nature and in the man-made world.