The same physics that explains how stars live and die also explained how to build a weapon that could destroy cities. This episode explores the scientists who calculated the inner workings of the sun and found their equations pointing toward both stellar astrophysics and nuclear weapons — the uncomfortable intersection where understanding the cosmos and engineering destruction use identical mathematics.

This episode examines the physicists who bridged solar science and weapons research, tracing the theoretical breakthroughs, the wartime applications, and the moral reckonings that followed.

• The physics of stellar interiors and how understanding the sun required understanding nuclear fusion
• The Manhattan Project and the direct line from astrophysics to weapons design
• The scientists who worked on both — and the ones  ...