Athol Rafter was a pioneer of radiocarbon dating – the Rafter Radiocarbon Laboratory at GNS Sciences, Lower Hutt, is named after him. Rafter played a part in the early development of what became one of the most important dating tools in archaeology. Even now, more than 60 years after the technique was first developed, improvements continue to be made to give greater accuracy and reliability.
The technique, first developed in America in 1949, created a revolution in the dating of archaeological material. Radiocarbon dating uses the carbon-14 isotope in organic material to work out the ages of once-living things. Rafter and colleagues immediately saw uses for the technique in New Zealand and tried it out. The new method proved to be a bit unreliable, so Rafter and his team set about solving some of the problems. Their improvements had a lasting impact on the worldwide use of the technique.
...the guiding principle must be ‘you must never give up’.Athol Rafter
Rafter went on to run the Institute of Nuclear Science in Lower Hutt, and the dating facility was renamed the Rafter Radiocarbon Laboratory to mark his 80th birthday in 1993. Radiocarbon dating has continued to improve. The original method counted radioactive particles given off by carbon-14 atoms. Since 1977, the isotope atoms have been counted directly, making the dating much more accurate. As part of Rafter’s scientific legacy, New Zealand continues to play an important role in these developments and now has two radiocarbon dating laboratories that receive samples from all over the world.
Another aspect of Rafter’s work has also left a lasting legacy. He and Gordon Fergusson were the first to notice an increase in radiocarbon in the atmosphere as a result of nuclear weapons testing in the 1950s. Measurements of radiocarbon in carbon dioxide in the atmosphere were started at Makara, near Wellington, in 1954. Data is still being collected by NIWA and is the longest running record of its kind in the world. Data from the programme plays an important part in recording increased carbon dioxide in the atmosphere, which is causing widespread concern due to its involvement in global warming.
The timeline below lets you see aspects of Athol's life and work, and how his findings changed scientific thinking. A full timeline transcript is here.