Instructables
Build your own avalanche disk to observe granular physics in action.  A single granule is a solid but when it interacts with many, it may behave as a solid, liquid, or gas.

I first saw one of these a while back in some science museum that I took Caitlin to.  It was more of an art installation where I thought the inside was like one of those lava lamp fluid things.   I recently saw a related video to an avalanche disk and it looks like  The Museum of Science and Industry - Chicago has one on display.  Theirs is 20 ft in diameter and weighs several tons.  This one scaled way down. It's one of those things - "How did they do that?" but more importantly, "Can you make it at home?"  Other than that, there is a field of science that applies to this.

Learning Objective: Build and use an avalanche disk to observe the behavior of granular solids as granules flow, shear, mix, separate and freeze.

Knowing how granular solids act is pertinent to helping you predict/prevent snow avalanches to designing machines to package your cereal.  Computer modelling can be quite complex.

Video of the Avalanche Disk in action (overdub with your best Carl Sagan impression on the creation of the universe):

 
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That's pretty cool! Thanks for showing me this. So the different sands have a different specific gravity and never really mix. I like the idea of the stargate table too :)

caitlinsdad (author)  --= Excogitate =--8 months ago

Thanks. It's great fun to figure out how things work and see science in action.

iproberry12 years ago
I suggest adding a motor to the avalanche disk! ;P
For your "Apparatuses or apperatii?" question, the plural of the noun apparatus is apparatuses, although in this context just apparatus should suit you fine!
caitlinsdad (author)  anonymouse1973 years ago
I do that for the fun anonymousii comments.
And so you should, commenti such as that are inspirational, and we need more inspirati in our lives.
SHIFT!3 years ago
Sweet! I remember seeing one of these at the Tec Museum but I never knew what the scientific name was for them. Thanks for the info!
caitlinsdad (author)  SHIFT!3 years ago
I thought it might have also been some kind of ferro-fluid. One more mystery of the universe revealed.