And as far as we know, it has been forming in the earth’s upper atmosphere since the atmosphere was made back on Day Two of Creation Week (part of the expanse, or firmament, described in Genesis 1:6–8). Cosmic rays from outer space are continually bombarding the upper atmosphere of the earth, producing fast-moving neutrons (subatomic particles carrying no electric charge) (Figure 1a).1 These fast-moving neutrons collide with atoms of nitrogen-14, the most abundant element in the upper atmosphere, converting them into radiocarbon (carbon-14) atoms.
CARBON-14 IS CREATED (Figure 1a): When cosmic rays bombard the earth’s atmosphere, they produce neutrons.
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The standard way of expressing the decay rate is called the half-life.5 It’s defined as the time it takes half a given quantity of a radioactive element to decay.
So if we started with 2 million atoms of carbon-14 in our measured quantity of carbon, then the half-life of radiocarbon would be the time it takes for half, or 1 million, of those atoms to decay.
Radioactive and non-radioactive carbon dioxide mix throughout the atmosphere, and dissolve into the oceans.
Through photosynthesis carbon dioxide enters plants and algae, bringing radiocarbon into the food chain.
These rapidly combine with oxygen atoms (the second most abundant element in the atmosphere, at 21%) to form carbon dioxide (CO).
This carbon dioxide, now radioactive with carbon-14, is otherwise chemically indistinguishable from the normal carbon dioxide in the atmosphere, which is slightly lighter because it contains normal carbon-12.
It’s assumed to be the same number of carbon-14 atoms as in elephants living today.
With time those sand grains fall to the bottom bowl, so the new number represents the carbon-14 atoms left in the mammoth skull when we found it.
If carbon-14 has formed at a constant rate for a very long time and continually mixed into the biosphere, then the level of carbon-14 in the atmosphere should remain constant.