Boiling an egg perfectly is not easy. Due to its different compositions (成分), the yolk (蛋黄) cooks at 65 C while the egg white at 85 C. A team at the University of Naples Federico II in Italy has found a new way to cook a perfect egg. It's called “periodic (周期性的) cooking”. In their study, the Italian team compared several traditional cooking methods with the newly discovered one.