Interestingly enough, our chosen project has roots in literature!
We decided to make oobleck. What's oobleck? The word, originally coined by Dr. Seuss, describes a non-Newtonian liquid. That means it doesn't conform to the laws of physics as laid out by Newton. It's not really a liquid and it's not quite a solid. When the oobleck is at rest, it acts like a liquid. You can pour it or swish it around and it conforms to the shape of its container. However, when you apply force (i.e. hitting or slapping it) it turns into a solid. There are videos on youtube of people running across pools of oobleck. If they go fast enough, they can run along the top, but if they slow down, the oobleck reacts like a liquid and they sink into the goopy mess.
Here's a quick video I made of our results:
The recipe is very simple. 2 cups cornstarch to 1 cup water.
The box of cornstarch I bought was 16 oz, so I figured, hey, 8 oz to a cup so the whole box plus one cup water. WRONG! I forgot there was a difference between solid and liquid ounces, so I ended up with a mess that was very much a solid and impossible to stir.
Silas was terribly unimpressed with the so-called "science experiment" that his daft aunt was trying to make. He ate dinner while my boyfriend and I desperately tried to mix the concoction, eventually gradually adding water. I also discovered that a material designed to repel force is terribly difficult to mix. When you push a spoon through it, it pushes back. But eventually, we got a successful result.
After the video, I showed Silas that you could put your whole hand in and lift up a chunk of the goo. While you squeeze it in your hand, it remains solid, but as soon as you let go, it turns back into a liquid and appears to melt out of your hand. His eyes lit up. He wanted to try too! So we moved the party to the bathtub...
...where we proceed to make a huge mess and have lots of fun. After we splashed all the oobleck out of the bowl, we simply turned on the shower and washed it down the drain. Messy science and an easy clean-up!
Everyone should try this inexpensive and fun project, even if you don't have a four year old nephew as an excuse! Let me know if you have any questions.