Did you know some of the most sensitive scientific instruments once relied on steel salvaged from sunken World War-era ships? Known as "low-background steel," this material is prized because it was produced before atmospheric nuclear testing began in 1945, which contaminated all steel manufactured afterward with trace amounts of radiation. This radiation doesn’t affect everyday use—but for delicate applications like Geiger counters, particle detectors, and some medical devices, even slight contamination can interfere with readings. That’s why divers were sent to retrieve steel from sunken battleships, especially those lost before the nuclear age, like the German WWI fleet scuttled at Scapa Flow. With modern smelting techniques and cleaner environments, the demand for sunken steel is now rare—but the story remains a fascinating example of how history and science can collide in the most unexpected ways. #RadiationScience #LowBackgroundSteel #ScientificHistory #SunkenTreasure #WWIIEngineering #MedicalTechFacts