/kloc-the research results of Scottish physicist J.C. Maxwell, one of the giants of physics in the 0 th and 9 th centuries, came out, and physicists had a clear understanding of the laws of optics. In a sense, Maxwell is the antithesis of michael faraday. Faraday has amazing intuition in experiments but has no formal training at all, while Maxwell, who is contemporary with Faraday, is a master of advanced mathematics. He is good at mathematics and physics at Cambridge University, where isaac newton finished his work two centuries ago.

Newton invented calculus. Calculus is expressed in the language of "differential equation", which describes how things smoothly undergo subtle changes in time and space. The motions of waves, liquids, gases and shells can all be described by the language of differential equations. Maxwell started his work with a clear goal-to express Faraday's revolutionary research results and his position with accurate differential equations.

Maxwell discovered from Faraday that electric field can be transformed into magnetic field, and vice versa. He adopted Faraday's description of the force field and rewrote it in the precise language of differential equations, and got one of the most important equations in modern science. They are a set of eight seemingly very difficult equations. Every physicist and engineer in the world must try to digest these equations when he learns to master electromagnetism at the graduate level.

Later, Maxwell asked himself a decisive question: If magnetic fields can be transformed into electric fields, and vice versa, what will happen if they are transformed into each other forever? Maxwell found that these electromagnetic fields can produce a wave, which is very similar to ocean waves. To his surprise, he calculated the speed of these waves and found that it was the speed of light! After 1864 discovered this fact, he prophetically wrote: "This speed is so close to the speed of light that it seems that we have every reason to believe that light itself is an electromagnetic interference."

This may be one of the greatest discoveries in human history. For the first time in history, the mystery of light was finally revealed. Maxwell suddenly realized that the brilliance of sunrise, the red flame of sunset, the gorgeous colors of rainbow and the twinkling stars in the sky can all be described by the waves he hastily wrote on a page. Today, we realize that the whole electromagnetic spectrum-from TV antenna, infrared ray, visible light, ultraviolet ray, X ray, microwave and gamma ray-is just Maxwell wave, that is, Faraday force field of vibration.

According to general relativity, when light passes through a strong gravitational field, it will be distorted.

Light has wave-particle duality.