If you look at the label of any food, you will probably find that it lists the Calorie content. Calories tell us how much energy you will get by consuming the food. How do scientists measure that energy?
I got the idea for this experiment while working on the rocks we collected recently. When we got home last weekend, we unloaded the 750 pounds of quartz crystals from our Arkansas trip onto the back patio. Then I left for Philadelphia to present some electricity shows. Today, I went out to unpack some of the boxes. We had wrapped the best crystals in newspaper, and all the newspaper that was exposed to sunlight had turned yellow. Cool! A chemical color change that happens fairly quickly, and is caused by exposure to light!
How do you feel? No, I don't mean are you happy or sad? Touch the back of your hand. Did you feel it? How? When you touched your hand, you pressed on nerves in your skin. These nerves reacted and sent a message to your brain, telling you that something touched your hand. Some parts of your skin have more nerves than others. We are going to examine how these nerves are arranged, and see how that can affect the message that your brain gets.
This experiment came from Diane in South-central Pennsylvania. She and her son were discussing ceiling fans, and how they make you feel cooler. They wanted to know if the fan actually cools the room, or does it just feel that way?
There are many things that will float on water: pieces of wood, wax, Styrofoam, and many other things. They float because they are less dense than the water. Now for the question. Can water float on water? Is there a way to make water less dense?
This experiment comes from my neighbors at the Malibu Creek State Park campground. While taking my morning walk, I heard a lady bragging to her husband that she started the campfire with only one match. That made me think of the fellow that I watched the night before as he poured two bottles of charcoal lighter fluid onto a pile of wood and still failed to get the fire going. He would pour on the liquid and get a huge blaze, which quickly died. How could the heat of one match work better than a gallon of blazing lighter fluid?