Analysis of growth rings from pine trees in Sweden shows that the proliferation of atomic tests in the 1950s and 1960s led to an explosion in levels of atmospheric carbon 14.
Now, Jonas Frisen and colleagues at the Karolinska Institute in Stockholm have taken advantage of this spike in C14 to devise a method to date the birth of human cells.
But the almost tenfold increase in atmospheric C14 that peaked around the mid-1960s has been followed by a rapid decline since the nuclear test ban treaties and the cessation of high-yield, above-ground nuclear tests.
In fact, C14 is assimilated so rapidly that from about 1963, its half-life in the atmosphere has only been about 11 years.
While carbon dating organic matter is not new, Van Houtan's method used something known as bomb carbon dating.
"There is a natural radiocarbon at low levels, which has a predictable signal over geological time," Van Houton explained.
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The levels of this material spiked during the nuclear tests during the Cold War and have declined ever since, so the the corals can be used as a kind of measuring rod.
Note that the position the "God made the Earth seem older." (also known as the Omphalos hypothesis) is unfalsifiable.
Therefore, it isn't a scientific hypothesis, but a faith-based one, and off-topic.
In a stratigraphical context objects closer to the surface are more recent in time relative to items deeper in the ground.
Although relative dating can work well in certain areas, several problems arise.
"Green turtles are far more numerous, having rebounded from their near extinction in the early 1970s, in concert with conservation protections under the ESA [Endangered Species Act].