Do you know tea and laser pointer have relationship?

The blue laser pointer is more effective (about 200 times) than the red laser pointer. The eyes are much more sensitive to green; In addition, the laser pointer light is more red. With various depths (3-4 kilometers), this pointer is ideal for astronomy. The laser wavelength is 532nm (blue), which presents the continuous emission of radiation. Therefore, its beam can be seen from the air, light or dark.