Peg, you really need to get your information from different sources. The sources you are using are totally ignorant of the subject. Or maybe they are lying. One way or another, they are useless as sources of true information.
Most of your points of contention are relevant to
some measurements. For your beliefs to be true, you need to come up with some problem that makes
all 14C measurements older than, say, 10,000 years false. Don't bother with anything that applies only to
some samples.
contamination of the samples tested for instance. Its always possible that a bit of wood, for example, from the heart of an old tree might contain live sap. Or if it was extracted with an organic solvent (often made from petroleum), a trace of the solvent might be left in the portion analyzed. Charcoal could have been penetrated by rootlets from living plants. Any of these scenarios could affect the levels of C14
Yes they could. Of course, nobody would use an organic solvent to extract a 14C sample. The other scenarios are possible, but would make the sample appear
younger than it really is… no help to you, you're arguing that the results are
older than the samples really are.
These kinds of contamination can often be detected. For your charcoal sample, test samples from different parts of the piece of charcoal. If the results vary significantly, there's a problem.
Live shellfish have been found with carbonate from minerals long buried or from seawater upwelling from the deep ocean where it had been for thousands of years. Such things can make a specimen appear either older or younger than it really is.
Oh, please. This is an old canard. Read some of the links given in this thread before you spew such garbage. Of course shellfish don't carbon-date correctly, 14C dating works on samples that get their carbon from the atmosphere directly or near-directly. It's well known that shellfish and most marine life don't fit that requirement, and we don't use 14C dating on such samples.
there is also the assumption that the level of carbon 14 in the atmosphere has always been the same as it is now. But we know that the carbon level has increased a lot since the explosion of nuclear bombs into the atmosphere and since the use of burning fossil fuels. So how do we really know what the levels were thousands of years ago
Well, at least this is relevant to whether the method itself is useful. But, Lord love a duck, it's an even worse
PRATT and one that has been already discussed in this very thread. No, there is absolutely no assumption that the level of 14C in the atmosphere has been stable. It is well known that it has not been stable (although it hasn't varied a heck of a lot). See
Message 23, read it, make sure you understand it, especially the calibration curve part. Then we can continue.
volcanic eruptions also add to the stable carbon-dioxide reservoir, thus diluting the radiocarbon....so how do they account for all these possible variances in c14 in the atmosphere??? How can they honestly know how much to make allowance for???
By cross-correlation with other, independent measurements. See
Message 23.
And read some or all of the links in
Message 24