From: Roy Mayeda (roy_mayeda@isd743.k12.mn.us)
Date: Wed Dec 18 2002 - 08:47:47 PST
Date: 18 Dec 2002 10:47:47 -0600 Message-ID: <975569617roy_mayeda@isd743.k12.mn.us> From: Roy Mayeda <roy_mayeda@isd743.k12.mn.us> Subject: Re: grain elevator and questions
Mike,
There's a nice demo of this on the NOVA "Kaboom" video. They show sprinkling a bit of flour into a section of heavy cardboard tubing (probably 5-6 feet long and 3-4 inches in diameter) with a candle at the bottom. The demonstrator seemed to rapidly tap small amounts into the tube to get the mixing effect Paul was talking about. Even though lycopodium powder is plant material, I guess it seems more like the grain elevator if you use flour. (What's really odd about the elevators I see out here is all the huge piles of soybeans and corn that sit outside in the dirt lots around the elevator until they can be shipped!)
About the sublimation thing -- I think water will also do this in the freezer, yes? Not sure about that (whether it sublimates or melts first). Seemed to me that if you leave ice cubes in the freezer a long time, they keep decreasing in size. Also, I think the term "deposition" was also used for the state change from gas directly to solid, though I also use "sublimation" for both processes sometimes as well. I think both were acceptable last time I looked it up.
Good luck.
Roy Mayeda
Sauk Centre HS
Sauk Centre, MN
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