Carbon dating nuclear bomb
Spalding and her postdoc advisor Jonas Frisén had a hunch that a pulse of radioactive carbon created by above-ground nuclear tests during the Cold War could help solve the riddle.
“A geopolitical phenomenon—this Cold War bomb testing—has, in a way, put a date stamp on everything and everybody,” Spalding says.
What was once a seven-proton nitrogen became a six-proton carbon.
But unlike most carbon atoms, which have six protons six and neutrons, this radioactive carbon, known as C, scientists use a technique called mass spectrometry, which sorts atoms by weight.
By 2050, Frisén and Spalding estimate, the bomb pulse will have completely dissipated.
These slammed into nitrogen atoms, causing their nuclei to eject a proton.Spalding would then spend hours chipping away to extract the necessary cells, a grisly procedure that was just the first in a decade-long stretch of hurdles she had to surmount.“Had we known how difficult it was going to be, we never would have stuck with it,” says physicist Bruce Buchholz, one of Spalding’s co-authors and an expert on bomb pulse dating at the Lawrence Livermore National Laboratory outside San Francisco.Our bodies are prolific artists, creating new cells throughout the body.Some cells, like those found in skin, hair, and the lining of the gut, are produced and discarded on a regular basis, like doodles on scrap paper. Kirsty Spalding was one of the scientists who doubted that assessment.