Differences in air pressure can lift an airplane, raise a table, or fill a bag.
The challenge: How many breaths of air will it take you to fill a plastic bag that’s 8’ (2 m) long and 10” (25 cm) in diameter? Depending on your size, it may be anywhere from 10 to 50 breaths of air, that is, if you have the stamina for it. However, with a little practice and some knowledge of how to use air pressure differences, you’ll be able to inflate the same bag with only one breath! When you can do that, there’s a whole lot more you can do with the bag, too.