Is a person lighter, heavier, or the same weight after they fart? Does it matter if the person is in Denver or Death Valley?
Lighter. Which is why tabloids are constantly touting “flatulence diets.” Those are more or less effective. You’re better sticking with “eat more fruits/vegetables and exerice.”
Quand les talons claquent, l’esprit se vide.
Maréchal Lyautey
Hmm… Flatulance contains methane and probably some air, so it is slightly lighter than air. So if it’s under one atmosphere pressure, having it inside your body gives you some lift, and getting rid of it makes you heavier. I’m not too sure if it IS at one atmosphere, but I’d guess it’s pretty close.
Interesting. You would lose mass, which should make you lighter, but if the mass you lost was bouyant, the loss then would make you heavier.
My guess is, overall, you’d get lighter by a fraction.