Italian mathematician Grimati said that light may be waves. He let a beam of light pass through two small holes and project it on the darkroom screen. As a result, he found bright and dark stripes on the projection screen. This is very similar to the diffraction of water waves, which shows the fluctuation of light. He also believes that objects appear in different colors because they have different light frequencies. British physicist Hooke said that light should be waves. Because he repeated Grimati's experiment with soap bubbles and mica,

He believes that "light is the longitudinal wave of ether", and the color of light is related to its frequency. How can light be waves? British physicist Newton said that this is obviously a particle. 1666, Newton took a vacation at home to avoid the Black Death, so he fiddled with the prism. He found that a beam of white light can be divided into different colors, and different monochromatic lights can also be synthesized and reduced to white light. To this end, he successfully explained the dispersion phenomenon of light. (See [Boiling Physics] (12): Good "color" person) Newton's spectroscopic experiment made optics leap from geometric optics to physical optics. Newton thought that light should be composed of particles and take the fastest straight path. The decomposition and synthesis of light is the result of the separation and mixing of particles of different colors.