I found two pairs of old and new leather shoes of the same brand and style for comparative observation. I first touched the uppers of two pairs of leather shoes and found that the surface of the new shoes was much smoother than the old ones. Old leather shoes are coated with shoe polish. After careful polishing, it shines a lot, but it is still not as good as new leather shoes. Is there a relationship between the brightness of leather shoes and the smoothness of uppers?
I brought a pair of old leather shoes that were not polished, and the uppers were uneven under the magnifying glass. Then, I circled two rough areas A and B on the leather shoes. Carefully wipe area A with shoe polish, and area B without shoe polish as a blank control. I found that the surface of area A is obviously smoother after wiping, and it is more shiny than area B when placed in the sun. Why is there such a big difference between them?
I think the teacher once said in physics class that the wall of the theater is uneven, so that most of the sound can be absorbed and the audience will not be disturbed by the echo. Similarly, light will be reflected on the surface of any object. If the plane is uneven, light will scatter in all directions. If this plane is smooth, then we can see the reflected light in a certain direction.
The surface of leather shoes is not absolutely smooth. If it is an old leather shoe, its surface is of course more uneven and can't reflect light in a certain direction, so it looks dull. There are some small particles in shoe polish, which can just be filled into the pits on the surface of leather shoes when shining shoes. If you wipe it with a cloth again, the shoe polish will be more uniform, the surface of leather shoes will become smooth and flat, and the reflective ability will be strengthened.
Through the experiment, I finally know the secret of shoes getting brighter and brighter!