38 x 21 x 4

This machine responds - with a dance of moving light - to ionizing radiation. It interprets for the senses some of the form of an invisible activity. Where I live, hits from background radiation average about one-per-second in chaotic intervals. This is my second machine built around a Geiger tube, and I have plans for about fifty more. No attempt has been made to calibrate this machine. It is quiet when a lead shield is around the detector, and it becomes very active when exposed to known radioactive objects.

High-res image

My "standard" is a small blob of uranium oxide (yellow cake) - mixed with epoxy on the end of a fiberglass rod. Not wanting to wittingly increase the odds against my immune system, I have a lead cap for this wand and I keep it carefully in one place.

A friend gave me a pottery bowl of a kind that is very popular and widely collected - it appears to be at least a hundred times more radioactive than my wand.

I built this handheld geiger counter to check steel we use in the shop when I heard that contaminated steel was being slipped into the recycling stream.