title: Popcorn: critical temperature, jump and sound.
abstract: Popcorn bursts open, jumps and emits a 'pop' sound in some hundredths of a second. The physical origin of these three observations remains unclear in the literature. We show that the critical temperature 180°C at which almost all of popcorn pops is consistent with an elementary pressure vessel scenario. We observe that popcorn jumps with a 'leg' of starch which is compressed on the ground. As a result, popcorn is midway between two categories of moving systems: explosive plants using fracture mechanisms and jumping animals using muscles. By synchronizing video recordings with acoustic recordings, we propose that the familiar 'pop' sound of the popcorn is caused by the release of water vapour.
authors: CNRS UMR 7646, LadHyX, École Polytechnique, 91128 Palaiseau, France emmanuel.virot@polytechnique.edu.
authors: Emmanuel
authors: E
authors: Virot
authors: LIPhy, CNRS UMR 5588, Grenoble University, 38401 Grenoble, France.
authors: Alexandre
authors: A
authors: Ponomarenko
mesh_terms: D000162:Acoustics; D003296:Cooking; D005502:Food; D008962:Models, Theoretical; D009038:Motion; D013696:Temperature; D014741:Video Recording; D003313:Zea mays
keywords: biomechanics; fracture; thermodynamics