investigations and experiments

Sail Fans

I got the idea for this experiment while driving around town. We were driving across the Bridge of Lions in St. Augustine, and I pointed out a sailboat that had a large fan-like propeller sticking up behind the sail. The propeller is attached to a generator, using the wind to recharge the batteries. We joked about it being a fan to provide wind if the breeze died down, which lead to a discussion about what would happen if you tried that. That lead to this experiment.

To find out what would happen if you did mount a big fan to blow on the sails, you will need:

Why We Use Soap

Today I spent some time rebuilding a transformer for my Tesla coil. I got the idea for this experiment as I was cleaning up, trying to get the tar and grease off of my hands. Have you ever wondered why we use soap when we wash things? What is so special about soap?

To find out, you will need:


Today I was so busy having fun that I put off working on this week's experiment. I had several ideas bubbling around in my brain, but nothing quite came together. Then, as I often do when I am looking for an idea, I picked up the first thing I saw and began playing with it. It happened to be a bottle of liquid soap. I turned it over and watched as the bubble rose slowly through the thick liquid. I knew that I had this week's experiment. You will need:

Static Cling?

This experiment comes from a question sent to me by a subscriber and her daughter. They wanted to know why plastic cling wrap clings. I thought I knew the answer until I began experimenting. That lead to more research and all sorts of interesting things. To follow along, you will need:

OJ Ice Crystals

This experiment comes from some of my wife's creativity. Our hotel has breakfast every morning, and she has been putting some extra orange juice in our freezer each morning. By evening, it is nicely frozen and ready to be eaten. Besides being delicious, it also offers a great lesson on the science of freezing. To try this, you will need:

Stirring Sand

I ran across the idea for this week's experiment (which is really more of a challenge), while researching another question. The more I thought about it, the more I liked it. It involves the unusual behavior of sand in a glass of water.

Strange Refrigerator Magnets

This experiment is one that I stumbled upon while working on another idea. That seems to happen to me frequently. I was planning to magnetize a needle, and as I was sorting through all the magnets on our refrigerator, I got sidetracked into playing with the rubber magnets (which are really plastic, not rubber). The more I played; the more interesting it got.

Fish in a Bucket

This week's experiment goes back to fishing trips from my childhood. As we caught fish, we put them into a large tub of water. I loved watching them swim around and around. I was told that if you weighed the tub, that it would not register the weight of the fish, unless they touched the sides or bottom of the tub. Was that right? Let's find out.