*giggle*
Friday, February 16th, 2007Average weight of human lungs: 234 g
Average capacity of human lungs: ~6000 cm^3
Density of air: 1.293 g/L
Density of helium: 0.1786 g/L
Weight difference of 6L of air and 6L of helium: 6.686 g
Verdict: No, human lungs will not float if you fill them with helium. :-(