Steel, glass (painted), brass, wire and four 150 Watt spotlight lamps, linked to an electronic circuit and a Geiger counter.
The Geiger counter, which is an ordinary battery-run Geiger counter, is housed in a steel box, whose walls are approx
4 cm. thick. When the Geiger counter is encapsulated in this fashion, background radiation is not registered. The particles,
myons, which the Geiger counter registers, stem from the collision of heavy particles from space and particles from
the Earths atmosphere. The collision with heavy particles causes a shower of particles from the atmosphere. By adjusting
a counter in the electronic circuit from 0 to 999 it is possible to set the number of particles to be registered before the
on-off mechanism is activated. For instance, for every 10th particle registered by the Geiger counter, the 4 lamps turn
off for the following periods, one period for each lamp: 2 secs, 4 secs, 6 secs and 8 secs.

Photo: Bent Ryberg.