The Timepix hybrid silicon pixel detector has been used to investigate the inverse square law of radiation from a point source as a demonstration of the CERN [at] school detector kit capabilities. The experiment described uses a Timepix detector to detect the gamma rays emitted by an [superscript 241]Am radioactive source at a number of different distances. Datasets for each distance were collected, processed and analysed using the Pixelman software suite and CERN's ROOT analysis software. The inverse square law approximation describes the data well, and so by following the experiment students can make the connection between the relevant elements of the physics curriculum and cutting-edge physics research. Additionally, an analytic model of the detector geometry is used to provide a comparable description of the data without the need for approximations. Such an exercise is typical of the kind of extension activity that can pave the way to students and teachers going beyond the physics curriculum and performing their own research with CERN [at] school.