Light is a kind of energy or external cause , which enters the eye and gives rise to the feeling of vision. Light makes the object visible , but it itself disappears. We do not see the light , but we see the illuminated object. Light is a kind of diffused energy. Red or red is a color or hue. The longest wavelength of visible light (approximately 625-740 nanometers) is the color that gives the sensation of color vision when it is exposed to the eye , red. If the wavelength is greater than this, it is called infrared ray , the human eye is not sensitive to it. Red is a basic color in the RGB color system. Its complementary letter is cyan. The complementary color of red in the general color disc is green. Red is a tragic elemental color in the RYB color system , but not in the CMYK color system. A religion of light is scattering or scattering. The light is scattered by air molecules or dust in its journey i.e. after scattering. How light is scattered depends on its wavelength. scattering = ∞1λ4 That is, the higher the wavelength of light, the less scattering. Of the seven colors of white sunlight (beni a sa ha k la) , purple and blue have the shortest wavelengths and orange and red have the longest wavelengths. As a result, blue light is most prone to scattering (so the sky looks blue) and red light is lowest. So it can go very far in the air, that is, it can be seen from a great distance. The red color is easily seen from a great distance. Due to which red light is used in traffic lights or some dangerous signals. For good reason , red warning lights are lit on high places (such as mobile towers , cooling towers) so that airplanes and helicopters can avoid them. The cooling towers used in nuclear power plants have a height of more than 150 meters. So as a precaution they are also painted red or red colored lights are lit. Also a tower is 100-200 meters from the ground. Which is much higher. When a plane or a helicopter flies through the sky, for some reason it has to go relatively low. If there is a collision with the tower while going down , there is a possibility of great danger. But if the color of these towers is red-white, then the tower can be seen clearly from any direction , above or below. Because the color of the sky is blue. In contrast to blue, red and white are clearly visible. That's why all mobile operators have tower colors and red and white. For this a red light is given on the top of the tower.