Oobleck is simple to make but the most messy fun you can have with your kitchen ingredients. All you need is some cornflour and water, about a cup of water mixed with a cup and a half of cornflour works well. You can add a bit of food colouring if you like. Green is slimetastic but go with any colours you fancy, pink and glittery can be lots of fun.
Now to experiment…
Try to decide if the Oobleck is a solid or a liquid. Try to press it hard, solid or liquid? Try pouring it, solid or liquid? It’s actually neither, it has a fancy scientific name of a ‘non-Newtonian fluid’, this means it can behave like either. Try stabbing it hard with a spoon, suddenly it’s solid, let the spoon rest on top and it sinks. Weird, huh? You can squeeze it into a ball, it feels all hard but as soon as you let go (or hand it to an unsuspecting victim!) it will collapse and go runny. Make up your own experiments, get your hands in it, get gooey and have fun. When you’re done, leave it to dry and keep for another day (don’t use it in the gravy though!).
The Oobleck gets even more odd if you get them vibrating. I’ve put some on an old speaker (covered in clingfilm) and played some loud music through it. If you get the right sounds, the oobleck will start to jump and dance about. There is a video on our Facebook page if you want to see this without risking your speakers! There are also some amazing videos on YouTube of people who have taken the oobleck experimenting to the extreme by filling whole swimming pools with it!
So what’s going on?
The tiny bits of cornflour have jagged edges, when you press them together they get stuck and can’t move past each other, so you have a solid. If you stop pressing, they come unstuck and can flow again like a liquid.