Oobleck

i’m no scientist and i don’t really understand these things, but it’s a suspension of starch resulting in this stuff that isn’t solid nor liquid. or it’s both at the same time. it’s kind of hard to explain. the name oobleck comes from dr. seuss’s book. if you leave it in a container, it seems liquid. if you try to stick in your finger or a spoon, it’ hard. if you do it at the right angle, you can penetrate it and pick some up in your hand. you can roll a ball in your hands, but the moment you stop moving it around, it starts oozing through your fingers. when you have it rolled into a ball you can throw it up in the air and it changes shape, but stays intact. my daughter wasn’t particularly interested in this stuff (and i didn’t let my little guy touch it because he would’ve only made a huge mess), but i played with it for quite a while. i couldn’t take pictures because you can’t keep it still in your hands for even a moment, or else it melts. it’s really fascinating.

i used this recipe and i was so intent on taking pictures of my daughter mixing it up that i didn’t realize that there was way too much water! you can see in the image below that it’s too liquidy. you need about half the water in this recipe.

after i found these instructions, which seem more correct. basically you add about half a cup of water to a cup of corn starch. i think it’s best to add the water a little bit at a time, constantly mixing, until you get to a very peculiar consistency. you can also add food coloring to make it even more peculiar/fun. (my daughter did some experimenting, mixing up colors to see what other colors they would make.)

luckily i realized that, if you leave it for a while, the starch and water separate and you can take out the excess water with a ladle. i was therefore able to get a good consistency, as you can see in the first photo. but if you leave it too long, the water evaporates and it dries out (see below). in any case, it’s a very interesting experiment to try out with kids (or grown ups!) and if you’re at all physics-inclined (or chemistry? i’m obviously not either!), you could make a nice lesson out of it.