In our daily lives, air appears as an invisible, freely permeable medium, but in reality, air, as a fluid, also possesses viscous properties. The viscosity of a fluid is essentially a form of internal friction, manifesting as resistance to relative motion between adjacent fluid layers. When two surfaces move at different speeds in the air, they pull on the air molecules between them, forming a velocity gradient layer, thus transferring momentum and energy. Our interactive exhibit, "Air Viscous Frisbee," is designed to reveal this invisible physical phenomenon. The exhibit measures 750*750*1500mm, with a simple and clear structure. After participants press the start button, the upper disc begins to rotate steadily under the drive of a motor. Then, by slowly raising the lower disc by turning the handwheel, a fascinating phenomenon occurs: although the upper and lower discs are not in direct contact, as the distance decreases, the lower disc also begins to rotate gradually.
