Carbon dating radioactive decay
07-Feb-2020 02:05
Researchers have come up with a physical argument to explain carbon-14’s anomalously long lifetime.
A peculiar balance of fundamental forces in the nucleus of the atom may keep it stable for thousands of years longer than expected — thus making radiocarbon dating possible.
Holt says that his team’s approach is not at odds with many-body calculations, but agrees that more work needs to be done.
“In order for this to be the nail in the coffin, we would need experimental evidence for these dropping masses as well as complementary calculation within the three-body community,” he says.
Carbon-14 is most abundant in atmospheric carbon dioxide because it is constantly being produced by collisions between nitrogen atoms and cosmic rays at the upper limits of the atmosphere.
They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.
Carbon-13 and carbon-14 are thus isotopes of carbon-12.
With a lifetime measured in millennia rather than minutes, researchers can use the decay of carbon-14 to date ancient artefacts.
But it was a mystery why carbon-14 hangs around for long enough to make this possible.
Some isotopes have half lives longer than the present age of the universe, but they are still subject to the same laws of quantum physics and will eventually decay, even if doing so at a time when all remaining atoms in the universe are separated by astronomical distances.