What caused these strange dust patterns?

No, unless you want me to disassemble one of my LCD calculators in the interest of science. :smiley: I built a polariscope once, and that was pretty neat, but that was years ago.

scr4, the tube is made of hard, rigid plastic about 1/8th of an inch in thickness. The whole tube is about 6 inches across. It was put away detached from the electric blower itself and has been sitting in a cardboard box with no wrapping or padding.

Squink, I admit “sealed from the elements” may have been an exaggeration. :slight_smile: It has been kept indoors and above freezing, however.

Q.E.D. - wow! You’re certainly hands-on! :wink: Did the pattern appear instantly, or did it gradually appear over time?

JRR, I don’t know the precise time frame for the development of the pattern. I allowed the charge to build up for about a half hour before flicking dust on the area, whereupon the pattern was immediately revealed. I would say that it took time to build up in this case, since a brief exposure on a previous trial did not appear to create enough of a charge to cause the dust to adhere in any coherent pattern.

Can you shed any light on the makeup of the material the patterns are composed of? Does it appear to be dust? Does it wipe or blow off easily, or is it fairly well bonded to the plastic?

The dust just seems to be just plain Kansas dirt.

As the smear on the photo shows, it wipes off quite easily.