His success initiated a series of measurements designed to answer two questions: Is the concentration of carbon-14 uniform throughout the plant and animal kingdoms?And, if so, has today’s uniform level prevailed throughout the recent past?The ultimate cause of carbon-14 variations with time is generally attributed to temporal fluctuations in the cosmic rays that bombard the upper atmosphere and create terrestrial carbon-14.Whenever the number of cosmic rays in the atmosphere is low, the rate of carbon-14 production is correspondingly low, resulting in a decrease of the radioisotope in the carbon-exchange reservoir described above.
To get them off his back, Gi Tae brings Joo Jang Mi (Han Groo) and introduces her as his future wife, knowing full well that his family would never accept her.
Radioactive carbon thus was visualized as gaining entrance wherever atmospheric carbon dioxide enters—into land plants by photosynthesis, into animals that feed on the plants, into marine and fresh waters as a dissolved component, and from there into aquatic plants and animals.
In short, all parts of the carbon cycle were seen to be invaded by the isotope carbon-14.
He and Jang-mi both learn a little about how important it is to communicate honestly, and I can only say thank goodness, it’s about time.
The occurrence of natural radioactive carbon in the atmosphere provides a unique opportunity to date organic materials as old as roughly 60,000 years.
After showing the essential uniformity of carbon-14 in living material, Libby sought to answer the second question by measuring the radiocarbon level in organic samples dated historically—materials as old as 5,000 years from sources such as Egyptian tombs.