The Physics of Jumping Popcorn
Have you ever wondered why popcorn "jumps" when it pops? This one-minute video from The New York Times shows the process in slow motion, narrating the key parts of a popcorn kernel's journey into a fluffy snack. It's based on a February research paper by Emmanuel Virot and Alexandre Ponomarenko. The paper is delightfully detailed—among other things, it compares kernels in motion to a gymnast's somersault. It also contains this passage in the Conclusion:
Concerning the jump, we found that a leg of starch is responsible for the observed motion. We note that the popcorn dynamic is twofold: the popping relies on a fracture as for explosive plants, while the jump relies on a leg as for animals. Concerning the ‘pop’ sound, we synchronized acoustic and video recordings: the scenario of an excitation by the water vapour release is consistent with our observations.
Science! Now here's video showing the popping process:
You can read more about the process from the Times.