An ultra-sensitive motion sensor placed next to the washer detected the movement and sent the signal up to an oscilloscope, or the headphones. As the membrane slowly returned to its original shape, the pressure difference slowly decreased. This explains why it was so hard to see the signal on the oscilloscope. The group is still working out a complete theoretical model for its whistling superfluid, but that hasn't stopped them seeking applications. Eventually, they hope to incorporate it into the world's most sensitive gyroscope.
Gyroscopes use rotating bodies to sense shifts in the direction of movement.
They are essential for navigation on board ships and aeroplanes, providing an absolute reference for their orientation and movement. The design of a superfluid gyroscope is based on the fact that these quantum liquids like to remain perfectly motionless. More specifically, they prefer to remain in a state of zero angular momentum. If you push one part of a superfluid one way, another part will move in the opposite direction to compensate. This removes excess energy from the fluid by pinching all the rotation down into a tiny tube.