I believe that friends often see many foreigners on the Internet watching passers-by "farting" outdoors with thermal imagers. As shown in the figure below, passers-by farting through the thermal imager will be recorded. To be honest, when I saw it for the first time, I thought that it must be very embarrassing if it was me, but can the thermal imager really see us "farting"?

There are many such pictures on the Internet. In fact, infrared thermal imagers cannot see people gasping and farting. So how did this come from? Of course, it is a P picture. Compared with solids and liquids, the density of gas is very low, the radiation intensity emitted will be very low, and the thermal imager is almost negligible, so you can't see "farts", so friends can be outdoors. Feel free to release yourself. At this time, a small friend asked, when the infrared thermal imager looks at the gas, it sometimes sees some black gas, why is this, it is because these gases absorb infrared rays, so they look black.