Traffic light light color scientific reasoning

The earliest time as long as the two colors red, green, later improved, increased a yellow light, red light indicated continuous, yellow marked ready, a green light indicates to traffic. Chose these three colors, using these three kinds of colour as traffic signals and person

 the first time as long as the two colors red, green, later improved, increased a yellow light, red light indicated continuous, yellow marked ready, a green light indicates to traffic. Chose these three colors, traffic signals and also with the three kinds of color people's psychological response of structure and vision. Human retina contains rods and three kinds of cone photoreceptors 【 Photoreceptor cells the study funded by the medical research council, the ophthalmology department at university college London r. robin ali leadership. 】 And rods 【 Rods? 吗? Photoreceptors in the retina, including the ability to start phytochrome in the process of scotopic vision. 】 Very bright yellow light, three types of cones, respectively for red, green and blue light is the most active. Due to this kind of visual structure, most briefly tell red and green. Although the yellow and the blue part is a brief, but as a result of eyeball of blu-ray adjustable photoreceptor cells is less, so know colour, or in the red, green is preferred. Traffic lights are not arbitrarily set. Based on optical principle, the wavelength of red light is very long, penetrating air capability is strong, and more attention than other signals, so as the signal of no thoroughfare, green chosen as the announcement signals, because of the difference of red and green is the most big, easy to determine ( Red and green color blindness' Red green color blindness ( 先天性红绿色盲,红色, 绿色盲,) Is part of the color blindness, divided into red color blindness and green color blindness. 】 After all, is a small amount of) 。 In addition, contains colour also can express a certain meaning, to express the heat or severe, most is red, the second is yellow. The implications of green has a cold and quiet. Therefore, risk people often with red yellow for caution, green for safety. The above content from huasheng new energy, reproduced please indicate.