A whirlwind tour of nuclear physics; Professor Weinstein explains the constituents of the nucleus; what holds the nucleus together; its role in determining atomic identity; the nature of isotopes; introducing two key tools.

The forces that shape the nuclei of all atoms; focusing on the curve of binding energy, which explains why heavy nuclei are prone to fission while light nuclei release energy by fusing; exploring the principles that govern particle accelerators.

Turning to unstable nuclei and the process of radioactive decay; tracing three types of decay; studying the particles involved; their charge; energy ranges; measuring radioactivity with a Geiger counter; shielding against each type of radiation.

Surveying the sources of radiation in the world, which include the sky, the ground, certain medical procedures and consumer goods; looking at some long-discontinued radiating products such as shoe fluoroscopy and the ill-advised tonic Radithor.