Of the 1332 posts I have polluted cyberspace with, the most frequently visited is a post on the topic of neutron lethargy written in May of 2008. The post is titled Neutron Lethargy- This Weeks Obscure Dimensionless Quantity. My intent was to write about some of the obscure yet interesting factoids and concepts that I run into in my daily travails.
I’ve been drawn to nuclear topics since junior high school. Sometime in 8th grade I began to to build several scientific projects as described in the Scientific American column The Amateur Scientist written by C.L. Stong. Stong published a collection of articles in a book titled The Scientific American Book of Projects for the Amateur Scientist, 1960, Simon and Shuster. This book was (is) a treasure trove of information on how to assemble equipment for scientific investigation.
In jr high I spent some time trying to assemble an “Atom Smasher” (p 344). It was an evacuated glass tube with filament electron source a meter away from the positively charged target. The target was a 3 x 1/4 inch disk of aluminum with many perforations over which aluminum foil would serve to seal in the vacuum. The aluminum foil was to serve as a window through which electrons could collide with a sample on the exterior. Sadly the project eventually ended due to the lack of access to a McLeod gauge, bulk mercury, and a diffusion pump. The required Van de Graff generator was available for a few hundred dollars. The failure was perhaps fortuitous because even if I had managed to assemble the thing, I might have been exposed to x-rays during the accelerator’s operation.
Turning my attention to more feasible projects I did manage to do some biology experiments. The most interesting was growing protozoans from an infusion of grass and soil in standing water. After several days the water would turn cloudy and fetid. Using a decent Christmas microscope we were able to view a magical world of microorganisms scooting around in their herky-jerky manner. It was mesmerizing.
A glove box project afforded a place for growing microorganisms with petri dishes purchased at a hobby shop. I was able to grow mold and some blend of bacteria on Jello in the petri dishes, but the microscope didn’t have the resolution for bacteria. Since I had no interest in pathogens, the glove box was not really needed. But it looked cool.
By 10th grade I did manage to successfully build the cloud chamber project (p 307). Unfortunately I only witnessed stray cosmic rays and background radiation. As it turned out, the polonium 210 alpha source loaned to me by a physics teacher had long since decayed to inactivity. Building the chamber was a tremendous learning experience made possible through the use of the metal shop at school. It was of sheet metal construction with a dry ice and methanol coolant chamber built in. The actual chamber was made from the bottom quarter of a Folgers coffee can cut and fitted with a glass viewing port and Plexiglass illumination ports. As I recall, the most problematic aspect of the construction was finding an adhesive that would not detach at dry ice temperature.
An electromagnet was built in an attempt to bend the path of the particles by a magnetic field, but was wholly inadequate for the job. Learned another lesson there too.
The book by Stong was something that lit up my curiosity and put a fire in the belly to explore. This was the beginning of what turned out to be life-long career in science. Strangely, the total lack of interest by the adults around me only strengthened my resolve to build and learn.