Neon is the beautician of the city. When the night falls, the colorful neon lights make the city more beautiful. So, how was neon invented? It is said that the neon light was discovered by the British chemist Ramsay in an experiment. It was one night in June 1898, and Ramsay and his assistants were doing experiments in the laboratory to see if a rare gas was conducting electricity. Ramsay injects a rare gas into a vacuum glass tube, then connects two metal electrodes enclosed in the vacuum glass tube to a high-voltage power supply, concentrating on observing whether the gas can conduct electricity. Suddenly, an unexpected phenomenon happened: the noble gas injected into the vacuum tube not only began to conduct electricity, but also emitted an extremely beautiful red light. This magical red light surprised Ramsay and his assistants, who opened the door to the neon world. Ramsay named the rare gas neon, which can conduct electricity and emit red light. Later, he continued to carry out experiments on the characteristics of conducting electricity and emitting colored light in other gases. He successively found that xenon can emit white light, argon can emit blue light, helium can emit yellow light, krypton can emit dark blue light Different gases can emit different colors and colors, just like a beautiful rainbow in the sky. The neon light also gets its name. The method of making neon lamp is to use sodium calcium silicate glass with low melting point as lamp tube, design different patterns and characters according to needs, process with blowtorch, then sinter electrode, and then vacuum pump, and fill different rare gas according to required color. Modern neon lights are more exquisite, some bend glass tubes into various folded shapes to make more moving graphics; some are coated with phosphor on the inner wall of the tubes to make the colors more bright and colorful; some neon lights are equipped with automatic igniters to make the lights of various colors go out in a bright and colorful way, making the city night more colorful. The neon lamp has been developing for a hundred years since it came out in 1910. It is a special low pressure cold cathode glow discharge light source, which is different from other arc lamps such as fluorescent lamp, high pressure sodium lamp, metal halide lamp, mercury lamp and incandescent lamp. Neon lamp is produced by glow discharge of cold cathode under high voltage electric field by low pressure inert gas filled into glass tube. The light color of neon lamp is determined by the spectral characteristics of inert gas: the light tube neon lamp is filled with neon gas, and the neon lamp emits red light; the fluorescent neon lamp is filled with argon and mercury, and the neon lamp emits blue and yellow light. These two kinds of neon lights are all based on the stimulated radiation of the working gas in the lamp tube.