The world's most sensitive radiation detectors sometimes rely on low background steel produced before the first atomic bomb test in July 1945, according to a new report from SpaceDaily. The report says that this gave rise to the popular story that scientists depend on steel salvaged from pre war shipwrecks resting on the ocean floor. The reason low background steel matters is that, in cutting edge physics experiments, even the detector's own walls can generate enough background radiation to interfere with measurements. In many cases, these newly produced metals perform just as well as their pre war counterparts, making the finite supply of old ship steel far less important than popular accounts suggest. When scientists are trying to detect just a handful of events over the course of an entire year, even the manufacturing history of the steel surrounding an experiment can make the difference between finding a signal and measuring nothing but noise.