Stroboscope is issued a flash at regular intervals. Use of human eye persistence of vision, so that a stationary object oriented dynamic. Measurable with stroboscope fan speed, flow rate drops, the vibration frequency of the string and observing a one-dimensional standing wave characteristics, etc., which may reveal some of the formation of a moving object, law, physical characteristics and inherent meaning. 
 
         In fact, rely on visual imaging lens of the eye, sensitive photoreceptor cells, and the optical signal is converted to nerve current return of the brain caused by human visual. Sensitive photoreceptor cells rely on some sensitive pigments, photographic pigment formation is needed for some time, which formed a visual pause mechanism. When fast-moving objects, when the human eye can see the image disappears, the human eye can continue to retain the image of its image 0.1-0.4 seconds or so, a phenomenon known as persistence of vision phenomenon. Is a property of the human eye has. When the human eye object image on the retina, the human brain by the optic nerve input, feel like an object. But when the object is removed, the object of the optic impression not disappear immediately, but to be extended 0.1 -0.4 seconds, the nature of the human eye is called "persistence of vision of the eye." 
          Persistence of vision phenomenon was first discovered Chinese people, according to a revolving door that is the earliest recorded history using persistence of vision. Song has been a revolving door, then known as "Maji light." Followed by Frenchman Paul Lo cover pictured dish invented in 1828, it was a rope through both sides of the disc. A face plate painted a bird, the other side drew a blank cage. When the disk rotates, the bird appeared in a cage. This proves that when the eyes see a series of images, it is time to retain an image.