Former U.S. nuclear weapons titan Lawrence Livermore National Laboratory is applying its bomb know-how to help solve police cold cases.
During the Cold War, above-ground nuclear weapons testing led to a marked escalation in global carbon-14 levels, from 1955 through 1963. While carbon-14 is in the environment naturally, the heightened levels from the bombs have been carefully tracked and recorded.Using accelerator mass spectrometry technology, the lab boosts ions to super high speeds to evaluate the half-life of their isotopes. Archaeologists use this sort of technology for radiocarbon dating. In this case, it registers the level of radioactive carbon-14 in the dental enamel or bones.Dental enamel doesn’t turn over like most tissue, so carbon laid down during tooth formation acts sort of like the rings of a tree, revealing their age.Scientists can then correlate the carbon-14 level with the records of airborne carbon-14 levels to figure out the age of the tooth and its owner to within 18 months. Other techniques are far less accurate, only narrowing age to within five or ten years.