Even the most cursory explorations into how scientific discoveries are made reveals that many of these discoveries are tinged with a certain serendipity and circumstances that are not immediately attributable to a wholly reasoned and logical progression of methodical experiments. Presented by the American Institute of Physics, this online multimedia exhibit tells the story of two important 20th century scientific discoveries: the discovery of nuclear fission and the detection of the first optical pulsar. The discovery of nuclear fission section contains audio clips from some of those responsible for this scientific endeavor, including Enrico Fermi, Arthur Holly Compton, and Otto Hahn. One particularly noteworthy clip features Compton's firsthand recollection of the first successful self-sustaining nuclear chain reaction under the bleacher of Stagg Field on the campus of the University of Chicago. The second exhibit hones in on the detection of the first optical pulsar, and includes clips from Philip Morrison, John Cocke, and Michael Disney. The site is rounded out by a set of teachers' guides designed to complement these online exhibits.