Whirly Tube

The spiral or corrugated tube, commonly called a whirly tube or sound tube, is a device used in demonstration experiments on wave transmission. When a tuning fork vibrates at one end of the tube, it creates periodic pressure variations inside it, which form a standing wave. It helps us observe the points of sound reinforcement and cancellation, which correspond to compressions and rarefactions, allowing us to understand that sound propagates as a longitudinal pressure wave and not as a transverse oscillation. It is made of aluminum.