As soon as it dies, however, the C ration gets smaller.
In other words, we have a ‘clock’ which starts ticking at the moment something dies.
It’s not absolutely constant due to several variables that affect the levels of cosmic rays reaching the atmosphere, such as the fluctuating strength of the Earth’s magnetic field, solar cycles that influence the amount of cosmic rays entering the solar system, climatic changes and human activities.
Among the significant events that caused a temporary but significant spike in the atmospheric carbon-14 to carbon-12 ratio were above-ground nuclear test detonations in the two decades following World War II.
Think of it like a teaspoon of cocoa mixed into a cake dough—after a while, the ‘ratio’ of cocoa to flour particles would be roughly the same no matter which part of the cake you sampled.
The fact that the C doesn’t matter in a living thing—because it is constantly exchanging carbon with its surroundings, the ‘mixture’ will be the same as in the atmosphere and in all living things.
, we find that this ration is the same if we sample a leaf from a tree, or a part of your body.is a term for radiocarbon dating based on timestamps left by above-ground nuclear explosions, and it is especially useful for putting an absolute age on organisms that lived through those events.In The Cosmic Story of Carbon-14 Ethan Siegel writes: The only major fluctuation [in carbon-14] we know of occurred when we began detonating nuclear weapons in the open air, back in the mid-20th century.Carbon-14 dating—explained in everyday terms by Dr Carl Wieland An attempt to explain this very important method of dating and the way in which, when fully understood, it supports a ‘short’ timescale.In fact, the whole method is a giant ‘clock’ which seems to put a very young upper limit on the age of the atmosphere.