Cornstarch + Water = Oobleck in the Morning and Sidewalk Paint in the Afternoon
I'm always surprised at the look I get from folks when I mention that we have been playing with oobleck. You know the look, the what did you say, I have no idea what you are talking about look... The one that reminds me time and time again why I love my job and the field of early childhood so much!
If you are giving me that look right now, let me fill you in on the wonderful that is......
Oobleck is simple, soothing, and one of the BEST ways to play with science! It only has 2 ingredients, cornstarch and water. Now, don't ask me for an exact recipe.... because I don't have one. In the tub today, we added 3 boxes of cornstarch and we slowly added and mixed water in until it was... just right!
The great thing about oobleck- is that it is seriously FUN to play with! It oozes and continually switches between the states of solid and liquid. This is what makes it a non-Newtonian fluid or a dilatant.
If you try to quickly grab or tap down on the oobleck, it acts like a solid.
However, if you slowly move your hand down into it, it acts like a liquid.
We tend to try to grab clumps of it as a solid and try to hold it in our hands....
but it doesn't last long because it starts to ooze out just like a liquid!
You can see in our photos that we didn't opt to add any coloring to our oobleck today. If you really want to add color, you can use some food coloring or liquid water color, but in all honesty... it isn't necessary.
Some of the most common questions I have had in regard to oobleck are:
- How do you clean it up? Well- in all honesty, if we play on the carpet, I just let it dry. It turns to powder and then we vacuum it up.
- How long does it keep? Well, I'm not sure. That would be a great science experiment. Oobleck is made with cornstarch, thus it will mold. So, if you keep it you need to dry it out uncovered and watch it closely. I do not recommend this, although I know that some people do it. We tend to play with it in the mornings or for one day and then turn it into sidewalk paint in the afternoon or next day. I also don't like to keep it around long because of the germs from all of those hands playing in it :).
Oobleck is so COOL even Dr Seuss decided to write about it!
When we are done playing with the oobleck,
we turn it into sidewalk paint!
There are many different tools and techniques that can be used to paint the sidewalk. With this paint- we just added some water to our oobleck to make it nice and runny- allowing all of the cornstarch to dissolve in the water. We also decided to use some lime green liquid water color today. You can use any color liquid watercolor (homemade or store bought) or food coloring.
We like to really get into painting our sidewalk....
Sometimes we use our fingers... and our toes...
Sometimes we make a giant puddle of paint and jump in it to "splat" it all around!
Sometimes we use brushes- we have found that regular paint brushes work okay,
but these handy little scrub brushes work so much better.
And... If we want to make nice circles- the best thing to use is a plunger!
How have you been playing with science?
We'd love to hear about it!
Oh, and don't forget- if you are looking for more sensory science fun download my FREE handouts!