Collective Voice: The 12,000 Pounds That Changed History
Today Periodic Tabloid welcomes guest blogger Ashley Levine. Levine participated in the authentication of a shield Willard Libby used in research on carbon dating, which won him a 1960 Nobel Prize. The instrument was donated to CHF by the Department of Homeland Security in February 2012.
When I was a senior at New York University I undertook an internship with Jonathan Mann, publisher of the historical Americana journal The Rail Splitter. I leapt at the opportunity to handle Civil War era documents, research obscure pieces of Lincolniana, and broaden my own scholarly interests.
I walked into Jon’s office my first day expecting to learn the ins and outs of cataloguing historical artifacts, but with a kind of restrained jubilation Jon told to me that something about my practicum had changed. He explained that the Atomic Energy Commission (AEC) formerly operated in his building, in the laboratories recently vacated by the National Urban Security Technology Laboratory (NUSTL). During the move one of NUSTL’s veteran scientists, privy to the activities of the AEC years ago, told Jon about some “iron shield” left on the building’s loading dock. He thought that it might be an instrument donated by Willard Libby, sometime after 1960—the year Libby won the Nobel Prize for developing carbon-14 dating.
In order to employ a Geiger counter (a particle detector that determines whether objects emit nuclear radiation) that could accurately measure the radioactive carbon-14 isotope, Libby had used a "shield," or iron encasement, that would limit radioactive background noise.
“We might have something big on our hands.”
Big? Yes. Try 12,000-pounds-big. Or window-into-the-prehistory-of-human-civilization-big. On the loading dock of our building sat a huge, worn apparatus that had possibly changed our understanding of history, and ourselves:
Jon and I needed to prove this suspicion, however, because the bulky iron machine was destined for the scrap yard. But how to authenticate it? Interviewing current NUSTL scientists appeared to be a good start. They informed me that Professor Naomi Harley, of NYU's department of environmental medicine, worked at the Atomic Energy Commission when Libby was its head. Professor Harley wrote to us, "I am quite certain that the Libby counter is the detector that Libby donated to the AEC after he used it for his cabon-14 dating experiments. I was not directly involved in the process when he donated the equipment, but I was aware that he did."
I mulled over the feedback: an artifact of this caliber doesn’t just pop up every day. Then it struck me that Libby actually described the shield in his Nobel Prize speech: "A typical shield…consists of eight inches of iron to absorb the radiations from terrestrial radioactivity, such as uranium, thorium, and potassium." I examined a grainy black and white photograph accompanying Libby’s published address:
After comparing this photograph to the 6-ton piece of iron on the loading dock, Jon and I were certain they were one and the same.
When Willard Libby received his Nobel Prize in 1960 for discovering the radiocarbon dating process, the Nobel Committee asserted, "Seldom has a single discovery in chemistry had such an impact on the thinking in so many fields of human endeavor." Using radiocarbon dating, archaeologists during the past 50 years have been able to obtain a global perspective on the timing of major prehistoric events such as the development of agriculture in various parts of the world. Historians (as well as geologists, biologists, and chemists) have benefitted from the radiocarbon dating process, and are now able to rework their research into this expanded global and chronological perspective.
Jon and I pursued this mystery with passion; as historians, we study the past to gain a better understanding of the world around us. Libby’s shield illuminated a world long-gone—yet its vital importance as an artifact for the ages resonates even more today.
Ashley Levine is currently an archivist for the PBS historical documentary series History Detectives.
Collective Voice, dispatches from CHF's collections team, appears every second Tuesday of the month on Periodic Tabloid.
CHF Acquires Libby Shield [YouTube]
Nobel Prize Lecture: Willard Libby [Nobelprize.org]
First Person: William McMillan [Periodic Tabloid]
Radio Isotopes for Peace [Chemical Heritage]