Radiocarbon dating estimates the age of organic material by measuring how much carbon-14 it still contains. Carbon-14 forms when cosmic rays strike nitrogen in the upper atmosphere, and living things absorb it along with ordinary carbon through photosynthesis and eating. When an organism dies, it stops taking in carbon-14, which then decays with a half-life of about 5,730 years. Measuring what remains tells scientists when the organism died, although the method is reliable only back to around 50,000 years. Willard Libby developed the technique at the University of Chicago in the late 1940s and received the Nobel Prize in Chemistry in 1960. Because atmospheric carbon-14 levels have varied over time, researchers use calibration curves built from tree rings and other records to convert measurements into calendar ages. Modern accelerator mass spectrometry can date samples as small as individual seeds.

In 1909 D. W. Griffith made a 14-minute film about a speculator who corners the wheat market and doubles the price of bread. A farmer sows his field while a 'Wheat King' gambles in the Chicago wheat pit; bakers raise the loaf from five cents to ten and the poor line up for bread. Griffith cut back and forth between the farm, the feast and the breadline, a technique called parallel editing, so audiences saw both ends of the economy at once. The film drew on Frank Norris's stories and on a real scheme: months earlier Chicago financier James Patten had cornered wheat, sent bread prices up and made about $5 million, roughly $185 million today.