Water droplets flowing backwards

By observing the states of water droplet backflow, stillness, and falling, we can understand the principle of visual persistence in the human eye. The exhibit consists of strobe lights and water pumps. By pressing the start button and adjusting the knob, you can observe that the water droplets are in a state of backflow, stillness, and falling. Due to the principle of visual persistence in the human eye, the impression of water droplets on the optic nerve does not immediately disappear when the eye observes them. It takes 0.1-0.4 seconds to see the effect of water droplets falling together. When the gap time of the strobe light is equal to the time interval when the water droplet falls to each position, it can create a visual effect of the water droplet being stationary. When the gap time of the strobe light is less than the time interval for water droplets to fall to various positions, it can create a visual effect of water droplet backflow. Target audience: Adolescents aged 6-15. Display format: Electromechanical demonstration device operation instructions (audience experience) 1 Press the start button and adjust the knob.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

Visual persistence: When the imaging light projected onto the human eye suddenly disappears, the visual image in the human brain will temporarily remain for about 0.1 seconds before disappearing. When the human eye is viewing a scene or image, the light signal projected from the scene or image enters the human eye and forms a clear image at the retina, thereby stimulating the retina to produce visual images in the brain. When the scenery suddenly moves away or the image suddenly disappears, the visual image in the human brain does not immediately disappear. In addition, the duration of visual persistence is related to the brightness of the observed scenery or image. The brighter the scenery or image, the longer the visual persistence moment; On the contrary, the darker it is, the shorter the visual persistence moment. Reference materials.