The Law of Gravity

My wife emailed me this morning:

Okay, this morning, one of the people that I work with told me that our balloons are defective. She couldn't believe that when she filled them up (by blowing into them) that they just fell to the floor and didn't float in the air. I told her that her breath is not lighter than the air that surrounds us and the balloon would fall to the floor. That it would need to be filled with something lighter than the air around us in order to float. Like h-e-l-i-u-m.

She swore up and down that balloons float when you blow them up with your own air, and got quite annoyed with me when I disagreed."

Just when I think people can't be any more stupid, one comes along.