From time to time, scientists make some quite surprising discoveries. The analysis of the age rings presented within a tree that was cut down can reveal a selection of carbon forms within it: carbon-12, carbon-13, and carbon-14. The ratios of the first two forms of carbon tend to be stable over time, but it seems that this is not the case with carbon-14.
Carbon-14 has a half-life of approximately 5,000 years and a common variation of 0.06% on a year to year basis. In 2012 a team of Japanese researchers made an exciting discovery during the analysis of tree rings from the years 774 and 775. There was a surge in the presence of carbon-14, with the variation being up to 20 times higher than usual.
Years of additional research were spent on the attempt to track down the cause, and a definitive culprit has been established: The Sun.
Carbon-14 Surge on Earth Over 1,000 Years Ago Was Due To The Sun
Our solar system formed billions of years ago from a molecular cloud of gas. Hydrogen and helium may have been the primary gases. Still, they were accompanied by a large number of heavy elements that were released in the universe in the aftermath of supernova events.
While carbon-12 and carbon-13 tend to be stable, carbon-14 has six protons and eight neutrons within its nucleus, a trait that makes it unstable by nature. Carbon-14 atoms, which were created before the formation of Earth, should have disappeared without a trace long ago.
However, carbon-14 is present on Earth, and its origin remained an enigma for a long time. The team of researchers has determined that they arrive with cosmic radiation, which is generated by the Sun, stars, black holes, and other objects. The surge was observed in tree rings from all over the world, and the scientists argue that it was caused by a gamma-ray pulse. A paper was published in a scientific journal.