On January 28, 1986, the Space Shuttle Challenger exploded just 73 seconds after launch, killing all seven astronauts aboard. President Reagan appointed a commission to investigate the disaster. Among its members was Richard Feynman, the 67-year-old physicist who was battling cancer and had reluctantly agreed to join the investigation. During a televised hearing, while officials debated the technical details, Feynman decided to demonstrate the problem himself. He took a piece of the rubber O-ring material used to seal the shuttle’s rocket booster joints, clamped it to simulate the pressure inside the joint, and placed it in a glass of ice water at approximately 32°F (0°C), the temperature at launch. After leaving it there for a moment, he pulled it out and released the clamp. The rubber remained compressed. It failed to spring back into its original shape. In front of the cameras, Feynman had demonstrated the problem in a glass of ice water. The unusually cold launch conditions had compromised the O-rings’ ability to seal the joints properly, allowing hot gas to escape and contributing to the destruction of the shuttle. His simple experiment cut through layers of technical jargon, bureaucratic explanations, and public relations spin. Anyone watching could understand the danger that had been overlooked. Feynman later wrote in his appendix to the official investigation report: “For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.”