How do night vision devices kill the night? You can't see anything outside on a dark and windy night when the moon is high, but if you wear night vision devices, it's different. Not only does it allow you to see things, but it also allows you to see Lao Wang.
So how does the night vision device achieve the night vision function? It was originally achieved through infrared radiation, which is divided into active and passive. The first invention was the active type, which was used in the military operation of the US military in 1945, that is, first irradiating an object with infrared rays, and then imaging according to the infrared radiation reflected from the object. This kind of night vision device not only has clear imaging, but also is simple to make. Unfortunately, it's too easy to expose your goals. Even a blind person can find you.
So, after some refinement, passive night vision devices appeared, which did not require the prior emission of infrared light objects. It is imaged based on the infrared radiation emitted by the object itself. Because clever scientists have discovered that as long as the temperature exceeds absolute zero, it is minus 273At 15°C, all objects produce some degree of thermal radiation.
What is the concept of absolute zero? In fact, everything in the universe is at a temperature higher than that, so this kind of night vision is actually universal to the entire universe, and it wants to peek at you, and you can't find it at all.
However, this night vision imaging is not clear, the resolution is too low, there can be no obstacles in between, or transparent objects. That's why there is today's low-light night vision device, as long as there is weak moonlight, starlight or lights, even if it is so weak that the human eye can't see it, he can also magnify its photoelectric imaging, so this is the king of night vision.