↑ Korff's paper actually referred to slow neutrons, a term that since Korff's time has acquired a more specific meaning, referring to a range of neutron energies that does not overlap with thermal neutrons.[6]
↑ Some of Libby's original samples have since been retested, and the results, published in 2018, were generally in good agreement with Libby's original results.[14]
↑ The interaction of cosmic rays with nitrogen and oxygen below the earth's surface can also create 14 C, and in some circumstances (e.g. near the surface of snow accumulations, which are permeable to gases) this 14 C migrates into the atmosphere. However, this pathway is estimated to be responsible for less than 0.1% of the total production of 14 C.[18]
↑ "PDB" stands for "Pee Dee Belemnite", a fossil from the Pee Dee formation in South Carolina.[39]
