By: lsayre On: Sun Oct 27, 2013 8:32 pm You may not like to hear this, but here is my opinion: Gases tend to mix rapidly through Brownian motion and van der Waals electrostatic forces, else the major components of our air such as nitrogen and oxygen and CO2 would not readily mix (and remain mixed) as uniformly as they do, and they would stratify out due to molecular weight and other differences.