Over the last year, I have been reading about and studying the different types of radiation and how they are detected, especially in the context of cosmic rays. This talk is about radioactivity.
Specifically: I will begin by giving a simple qualitative description of some core physics “laws” or “principles”. Then, based on these, I will describe the processes that lead to the various types of radiation, and how and why they interact with matter. I will describe a very simple device that can detect ionizing radiation – the Geiger-Müller tube. Finally, I will go over some examples of radioactivity – the decay chain of uranium-238, the chain-reaction fission of uranium-235, and the concept of critical mass.