To be able to date an object, you need to know how much carbon-14
was in it to start with.
The amount of carbon-14
in the atmosphere varies with fluctuations in solar activity and Earth's magnetic field, and "raw" radiocarbon dates have to be corrected with "calibration" that takes these natural fluctuations into account.
Radiocarbon or carbon-14
is produced naturally by cosmic ray interactions with air and is present at low levels in the atmosphere and food.
Thanks to carbon-14
, we've been able to date the Dead Sea Scrolls, most of which are made from goat skin.
The basic argument for a young earth from the presence of carbon-14
in coal and diamonds is that they cannot be older than about 50,000 years even using uniformitarian assumptions about the concentration of atmospheric carbon-14
analysis was also added after 1949 to date artifacts emerging from the systematic exploration of numerous sites from Alaska to Patagonia.
He was able to show using Carbon-14
labels that the N-methyl groups of several alkaloids came from the S-methyl of methionine.
The chemicals were radiolabeled with carbon-14
Max Uhle, the first archaeologist to study those early mummies, was not privy to carbon-14
dating technology though, and he mistakenly estimated their age at a mere two thousand years.
Scientists know that carbon-14
loses half its radioactivity (half-life) every 5,570 years.
Manual tests that mass spec-based breath analyzers are replacing or competing with include carbon-14
glycine cholate tests for bacterial overgrowth, carbon-14
lactose breath tests, carbon-14
stool excretion intestinal biopsies, intestinal intubations for culture intestinal perfusion, lactose barium radiography lactose tolerance tests, and stool pH tests for fecal reducing substances.
The resulting levels of carbon-12, carbon-13, and carbon-14
in atmospheric methane reflect these source and sink contributions.