I did two very simple experiments with my four year old son yesterday. Actually, I set up the experiments, showed him how to do them, and let him run them.

The first experiment was the classic mixing of baking soda and vinegar. I gave him three bowls, one with baking soda, one with vinegar, and a 3rd empty bowl to mix the two. I also gave him two spoons so he could move the baking soda and vinegar into the mixing bowl. I showed him how to mix two small amounts together and watched him giggle as it fizzed. I then walked away and told him to experiment with it, and went to do some dishes. I kind of watched him out of the corner of my eye and noticed that he did the predictable, which was to mix more and more of each of the ingredients, trying to make more bubbles and fizzy sound. Lesson learned? Mix more stuff together and you get a bigger chemical reaction. All I did was give him the language to describe what he was watching, he did the rest.

The second experiment I took 2 different sized salts and some more baking soda and 3 bowls of water. We mixed each bowl of water with the dry ingredients and stirred the bowls. My son was amazed as the baking soda, "disappeared." We stirred and stirred and then the regular salt "disappeared." After much more stirring, we finally got the coarse salt to disappear. We talked about what happened, and my son tasted the water (oops! I told him that he should ask me next time if it is safe to taste our experiments) and said, "Daddy, it’s so salty!"  Lesson learned? Stuff that "disappears" in water doesn’t actually "go away" it dissolves into the water.

We also played with a couple of other simple ideas, like filling up an upside down bowl with water without it pouring it out. We also figured out which makes ice melt faster, warm or cold water.

Basically my son did the work, and I set up the experiments. At the end of our 45 minutes or so playing around with the experiments, he still wasn’t done. He wanted more experiments. I couldn’t think of any more examples off the top of my head, so we sat down and I Googled some more experiments and we decided together on some experiments that we want to run.

Today I watched as my son stacked more and more cookies underneath his fork during dinner. When I asked him what he was doing, he said, "I’m doing an experiment Daddy!"

I’ve got him hooked.