Flatulance in cold weather...

…Why is it that you don’t see the trail from flatulance in cold weather like you see your breath? I’ve conducted experiments consisting of having friends (with my friends, a few drinks, and they’ll do anything) go out side naked in the snow, bend over, and let 'er rip. Nothing. Why can you see your breath coming from your nose and mouth, but nothing from the arse?

Apparently there’s a lot more moisture in your breathe than your flatulence.

The vapor trail you see is the moisture from your nasal passages, throat, etc. This moisture system is designed to humidify the air before it gets to your lungs. A side effect of this system is that air going out (your mouth, that is) is very humid. No such system is in place for your other end :slight_smile:

Arjuna34

I’s say because of how much surface area water can pass through.
A fart consists mostly of methane and hydrogen, while an exhale contains nitrogen, unabsorbed oxygen, carbon dioxide, and water vapor—due to the large surface area of the lungs aveoli (I think that’s how its spelled).
The rectum and lower intestine has much less surface area, and besides, those areas absorb water, not emit it.

Because the dew point for methane and hydrogen is much lower than for water vapor. :D:D