Which of the three colors of traffic lights has the longest light wave?

There are three colors of traffic lights, and the red light wave is the longest.

The three colors of traffic lights are red, yellow and green. The length of light wave is related to color, and different colors of light wave have different wavelengths. Generally speaking, the wavelength of red light is the longest, followed by yellow light and green light is the shortest.

Specifically, the wavelength corresponding to red light is longer, about 620-750 nanometers; The wavelength of yellow light is between 565 and 590 nanometers; The wavelength of green light is between 495 and 570 nanometers.

This is also the reason why in traffic lights, the red light is on for a relatively long time, followed by the yellow light and the green light is the shortest. Because of the long wavelength of red light, strong scattering and refraction ability, it has better penetration in distance and can better attract the driver's attention. However, the wavelength of green light is relatively short, and the scattering and refraction are weak, so the distance is relatively close, which is suitable for short-distance signal indication.

It should be noted that the wavelength of light mentioned here refers to the wavelength in the visible spectral range, which may be different for other spectral ranges.

Precautions for observing signal lights

1. Observation: During driving, always observe the traffic lights and pay attention to the changes and instructions of the lights.

2. Confirm the color: traffic lights generally have three colors: red, yellow, green and yellow. Red means parking, yellow means warning and green means traffic. Be sure to understand the meaning of each color accurately.

3. Distance judgment: When looking at the traffic lights, keep a certain distance to ensure that you can clearly see the changes of the lights. Don't get too close, so as not to affect observation.

4. Comprehensive judgment: traffic lights are only a part of traffic rules, and other factors, such as traffic flow, road conditions and pedestrians, need to be comprehensively considered to make correct judgments and decisions.