Tonight I was remembering a summer when I was part of an expedition to dig dinosaur bones in South Dakota. We set out tents up on top of the bluff, where we would have a nice view of the area and because it was very close to the bone quarry. While we were at the quarry digging, the wind came up and our tents were blown quite a ways down the hill. It only took us three trys to give up and move our camp down into a ravine. At least we found lots of dinosaur bones.
Quite a bit of my travels involve changes in altitude. Going from sea level to over 7000 feet makes a big difference. As you go higher, the air pressure is less. This can do bad things to the stuff in your suitcase, such as causing shampoo to squirt all over your clothes. It would be nice to fly all of you up into the mountains to do this experiment, but I can't quite afford that right now. Instead, we will cause a change in air pressure by heating and cooling it.
This experiment came as an accidental discovery while working on a different experiment idea. I was playing with ideas for showing how inertia helps remove water from your clothes in the spin cycle of the washing machine. In the process, I saw something interesting, and made a wrong guess about the cause. That led to even more interesting discoveries. There are times when it is more fun to be wrong, because it lets you learn new things.
This experiment comes from a question sent to me a homeschooling mom named Elaine. It is based on a "classic" experiment often seen in textbooks to show that air has weight. While it starts simple, it takes some twists along the way that often cause people to misunderstand what is actually happening.