Sunday, 17 November 2013

Playing with Oobleck

Princess loves messy, sensory play, it really calms her and we have been trying to do more of it so today we made Oobleck for the first time. If you have never tried making it before like us, please please do give it a go, its great!

To make oobleck, you will need:
1-2 cups cornflour (also known as cornstarch)
1/2 cup water
Food colouring

Put the cornflour in a bowl and mix in the water, you can either add the food colouring to the water, or put it straight into the oobleck mixture (or a bit of both like we did as Princess kept asking for more pink!) Add more cornflour or water gradually until it feels ready.

You will know it is ready when it is liquid when you sink your hands in slowly but feels solid when you tap it quickly. Here comes the science bit...... Oobleck is known as a non-Newtonian fluids as changes  pressure can change the properties of it. It feels solid when tapped quickly because the pressure forces the cornflour particles together whereas when you put your hand in slowly the particles have time to move out of the way so the oobleck behaves like a liquid.

I gave Princess a pot with a lid to play with and she had a great time scooping up and grabbing the solid oobleck and letting it drip off her hands into her 'cake', then putting on the lid and shaking it.

Next she decided to make some 'tea' which involved grabbing the oobleck and transferring it to the cup. This entertained her for quite a while as she enjoyed feeling the oobleck drip through her fingers. Grapie and I also had a go, Grapie didn't like the feel of it and wanted her hands washed straightaway, but I loved it and actually once Princess had finished playing with it, I kept it for a few hours and couldn't resist poking it every time I passed!

This is what the floor looked like at the end, but it was so easy (and fun!) to clean up. I scooped most of it up an put it back into the bowl, where it 'melted' back into liquid after seeming to have dried up on the floor. The rest cleaned up with a couple of baby wipes. This is definitely something that we will be doing again, it was just so much fun!