Question about flatulence?

Question

Considering that warm air rises, if a man builds up gas and the ambient temperature is less than his body temperature, does he weigh less than when he does not have gas? If he ate a pound of beans, would he weigh more or less? Going further, if one ate enough gaseous food, would they ultimately float off into space?

Answer 1

Flatus, even in a significant volume, will not add significantly to one's weight, irrespective of ambient temperature.  After eating a pound of beans the man would weigh approximately 1 pound more than he did prior to eating said pound of beans.  By conservation of mass, there is no reason for the man to weigh more.  The volume of flatus that would be required to overcome the earths gravitational forces would be so large that it would be incomcapatible with life as such a volume could not be contained within the peritoneum at body temperature.  Even if anatomic factors were excluded, e.g. the man had a container the size of a hot-air balloon which could maitain initial temperature of the flatus, as the density of the atmosphere approaches the gross density of the stored flatus, the man-balloon apparatus simply would not float beyond a given altitude.