RACEMIZATION:  #scifi Not science fiction, but a perfectly valid scientific dating technique. (Google it.) A simple explanation is that most living creatures produce amino acids of only ”left-handed” (L) orientation. After death, some of the L amino acids revert to “right-handed” (D) form, and the tissue samples gradually approach an even balance of L and D amino acids. Expressing the L/D ratio as an age is complicated by the fact that the rate of racemization varies with the amino acid, the temperature, the pH, the humidity, and other factors, most of which may change over the history of a sample.  The sample in Homecoming was close to ideal—death in an anoxic submarine landslide—but the best guess at date was “fairly recent.”