It's true. Part of you knows it's true and wants to accept it
and part of you knows it's false and wants to reject it. In the
end, as long as you have water, you can still drink. I like the
engineer's perspective - the volume in the glass is in a state
of partial equilibrium, consisting of 50% water with dissolved
gases and 50% air with water vapor. Ok, I made that up, but it's
based on something I've heard :) "
