Slime, oobleck, cloud doughs and the like are all popular fun for most children; they generally delight in the grossness and chance to get mucky. But if, like me, you have children who are reluctant to get their hands dirty, have a go at making out Autumn Oobleck to let them enjoy the sensory science experience without getting a spot on them!
Autumn is just starting to show its colors here. The first few trees are starting to turn and drop a few leaves, squirrels are stocking up on acorns and nuts and there’s a few autumn treasures to be found on the ground for us nature hunters. This week we went out for a short walk, sorry, I mean ‘ autumn scavenger hunt’ to build our hiking prowess and used our finds in a little sensory fun back inside.
As some of you might have heard me say before, my boys are more than happy to dig in the dirt but neither will tolerate finger painting, slime or sticky sensory play. I still like to offer up these experiences though, even if it ends up being me who gets mucky! This time I got smart though and added tweezers to our oobleck experiment so that everyone could get stuck in.
Little Brother loves tweezers for some reason, back when he had just 10 words tweezers was right up there on the list! He’s a dab hand with them too. I’m always looking, short of buying him ‘Operation’ and starting surgical training (just kidding!) for new ways to play with them. Moving small items in and out of ooblack was a great way to up his fine skills because of the resistance it provides and extra effort he had to put in.
Oobleck is a non-Newtonian fluid, it is a liquid until you apply pressure when it feels solid . It doesn’t follow Newton’s laws of viscosity. The name ‘oobleck’ comes from the 1949 Dr Seuss book ‘ Bartholomew and the Oobleck’ where young Bartholomew Cubbins has to save his kingdom from a sticky green substance called oobleck. Not one I ever read in my British childhood but hugely popular here in the US!
The recipe is very simple. Mix 1 part water to 1.5 – 2 parts cornstarch (corn flour); you just need to add that last half part slowly to play around with the consistency. For this activity we used the following:
- 1.5-2 Cups Cornstarch
- 1 cup of water
- A few drops of liquid color (optional) (UK)
- A collection of natural autumn treasures!
- Children’s’ tweezers (UK)
Mix the water and cornstarch in a bowl and pour it onto a baking sheet or into a dish of some kind.
Transfer, or have the children add to the tray a selection of the treasures – leaves, acorns, sticks, seeds – to the oobleck. They can observe how initially the items sit on top of the harden liquid but then sink into the pool of it as the oobleck relaxes.
We played around with the items like this for a while, marveling at how much resistance the oobleck gave and how tricky it made it to pick up our treasures. As the novelty started to wear off we moved on to color mixing.
I added a few drops of yellow and red liquid water color to the surface of the oobleck and asked Little Brother to stir them in to find out if his color mixing predations were correct. Ooh. I’m mean! It is of course pretty tricky to stir a non-Newtonian liquid with tweezers as is becomes solid with pressure. We experimented with different ways of mixing and spreading the colors – lifting the tray too let the oobleck pour being the most effective.
The result was a delightful looking mess and lots of fun hands on learning – but happily still clean hands for those that wanted them. Of course if the children want to stick their hands in that’s great. Be my guests!