Saturday, April 16, 2011

Oobleck

Lydia decided to do her science fair project this year on "Oobleck". Oobleck is basically corn starch mixed with water (not too much water, just enough to make it goopy); it has all sorts of very odd characteristics. The main thing that's interesting about it is that it tends to "seize up" when struck/grabbed/poked/pounded, behaving more like a solid than a liquid. For example, if you slowly push your fingers into the mix and then pull them out, it looks like any other goopy liquid:




On the other hand, if you then take your finger and poke the oobleck hard, it feels as though you are poking a hard piece of plastic. You can punch it and your hand will bounce right back:



If you take a block of wood and put it into the bowl, it will float (of course). You can then take a hammer and bang a nail into it, and at the end, it's still floating (?!?!):



There are all sorts of interesting videos on YouTube; here are a couple:

http://www.youtube.com/watch?v=lDzampa3xrc
http://www.youtube.com/watch?v=r7a84816i_g

Next: Lydia at the science fair herself, with the poster and exhibit that she made (with some help from mom and dad):

  
[Apologies for the focus-- I'm afraid the lens on my camera is in bad shape-- the autofocus is nearly shot; I need to send it off to get it repaired]

The fair was a lot of fun-- it's amazing the stuff that kids can come up with. I spent most of my time hanging out with Lydia, but I did take a stroll around to look at some of the other exhibits (there must have been at least 50 or 60).