Atomic nuclei that transform spontaneously into other nuclei and begin to radiate. A process that takes place in nature, optimized by humanity, to simplify things a bit. Invisible radiation leading to visible results. Archaeology, geology, forensics, and other disciplines define the age of their objects of research with the radiocarbon method. Geophysicists and medical doctors use radioactive substances to control the flowing behavior in the ground or in tissues. The successors of Marie Curie, harnessed radioactivity. Hiroshima, Harrisburg, Chernobyl, Fukushima… Visible results: new genetic mutations, resettlement programs, demonstrations, parties, and laws. Invisible radiation rendered visible, materialized. The material is up for debate. We wonder, don’t thought processes have something radioactive about them?