On 5/24/2013 3:31 PM, Eisboch wrote:


"F.O.A.D." wrote in message
...


We had "projects" in 5th and 6th grade that required work at home, but
mostly at the library or the museum or some other venue. Real homework
started in junior high, 7th, 8th, and 9th grade, at least a couple of
hours a night every weeknight. I got an A+ on a junior high science
class project, a working cloud chamber, made from a glass cylinder cut
down from a jug, two bands of copper, wire, a cookie sheet painted flat
black, dry ice, a spark coil from an old ford, a battery, radium scraped
off an old alarm clock dial, and use of the class filmstrip projector. I
spent a lot of time researching and building that one. Got a dad from my
scout troop who worked at a Yale bio lab to cut the glass cider jug into
a cylinder.

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I helped my son with a "cloud chamber" also except I used an entirely
different approach. Had a small glass "bell jar" to which a vacuum
pump was attached. When you start lowering the pressure within the
bell jar the water vapor contained in the atmosphere cools and expands
almost instantaneously, creating a very visible vapor cloud. Similar
process to what occurs naturally due to transitions from high to low
pressure areas in the weather.

The "cloud" doesn't last long. It's referred to the "Wilson Cloud", I
guess named after some dude or dudette named Wilson who first observed it.

My dad and I built a generator powered city once... and I built a small
computer that could do math based on a game I saw on TV...