Flying Machine (video) American Physical Society Loading video... Caption A jellyfish-like flying machine hovers in air by flapping its four wings 20 times per second. Credit NYU/L. Ristroph Usage Restrictions This video may be used only with appropriate caption and credit. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.