Historians can tell what cultures thrived in different regions and when they disintegrated.
Radiometric dating relies on the properties of isotopes.
These are chemical elements, like carbon or uranium, that are identical except for one key feature — the number of neutrons in their nucleus.
Indeed, by doing almost 20 seconds of research on google (type in “variations in C14”, click on Google Scholar) the second link is this article from 1954: Carbon 13 in plants and the relationships between carbon 13 and carbon 14 variations in nature So, this issue has been known about for a long time. Then we compare the two and adjust the radiocarbon date to the known date. That’s less than 1% if you’re interested in that sort of thing. But this is already almost a thousand words and I’ve only done ONE! Long story short, scientists have always known that variations in C-14 concentration happen.
Do you honestly think that no one has done anything about it? By making thousands (if not millions) of these adjustments we get a very good idea of how old a piece of unknown material can be. The 2009 calibration set extends the ‘well calibrated range’ to 50,000 years using the varves in a Japanese lake. This is unlike the creationists which think it happened, but can’t be bothered to check.
Atoms of radioactive isotopes are unstable and decay over time by shooting off particles at a fixed rate, transmuting the material into a more stable substance.
For instance, half the mass of carbon-14, an unstable isotope of carbon, will decay into nitrogen-14 over a period of 5,730 years.How do scientists know the bones are really 68 million years old?Today’s knowledge of fossil ages comes primarily from radiometric dating, also known as radioactive dating.Only hard parts, like bones and teeth, can become fossils.But for some people, the discovery raised a different question.The other is that the decay products of various atoms are always the same. Just looking at this list, I can see that none of these are actually assumptions used by radioactive dating methods and/or they are known issues and compensated for. Something that this particular website has none of. Basically, just like all creationists, they are making stuff up and then hoping you won’t check them on it. 1) atmosphere has always had the same amount of C-14 This is obviously in reference to carbon-14 dating of formerly living tissue.