Why'd you change? All of the mechanisms that you listed are based on each other. They just play around with the fudge factors to make the numbers match. Look at carbon dating, for example: there's an arbitarary fudge factor to account for the "changing rate of carbon entering the atmosphere from space". How do they get this? They get it from artifacts that they're trying to date! There's also dendrochronology, which means you've got half a million old logs, and because this one has a dent in this one side and this other one does too, we're going to say that those dents were from the same year, and "voila!" -- we've got a single line of trees going back for millenia.
If I had tried to pull the sort of stunts in my science classes back in high school that professionals do (and get published doing!), I'd have failed out. And rightfully so. You don't just guess that two things match, and you don't just make up fudge factors when your numbers don't work out.
For example when observing ice cores near the poles when we look down 26 rings we see ash that matches the ash from Mt. St. Helen's. When we look down 1937 years we see ash from Pompeii. So if going down 2,000 rings matches with 2,000 years of recorded history, than it isn't a stretch to apply this to 100,000-200,000 years.
They get it because they can calibrate the dating based on several other known methods of dating. In any case, the margin of error that has been found still puts the dating of many things long before the earliest Christian creation dates.
There's also dendrochronology, which means you've got half a million old logs, and because this one has a dent in this one side and this other one does too, we're going to say that those dents were from the same year, and "voila!"
A standard tactic of the anti-science crowd is to put out a warped, gross simplification of the science to the believers so they can then go tell their friends how science is a fraud.
>>Why'd you change?<<
For myself, the more I studied science, the more things seemed to come together, patterns emerging from the chaos. The way you can study chemistry and rock weathering while somebody else studies radioactive decay and others study sediment layers and still others study stars and it points to a unified whole with consistency but with enough questions to intrigue us forever. We are only now making reasonable guesses as to the age of the man, the earth and the universe. It took 5400 years from the time Egyptians began their recorded history to discover atoms and in the next hundred we found what they are made from, how to split them, how to combine them and how to read the ages.
The beauty that we can't live without Iodine but Iodine is only formed in supernovas and there are only four supernovas in our galaxy. To think that the iodine had to travel for millions of years so that I can have it as an additive in my salt an thus live is just staggering.
The way Pi is found in the tiniest particles and every circle and black holes we can only detect because they block out light sent from stars 5 billion years ago - it made me ready to hear God.
Your understanding of radiocarbon dating is sadly lacking. Here are some links which may help -- if you bother to read them:
ReligiousTolerance.org Carbon-14 Dating (C-14): Beliefs of New-Earth Creationists
This site, BiblicalChronologist.org has a series of good articles on radiocarbon dating.
Are tree-ring chronologies reliable? (The Biblical Chronologist, Vol. 5, No. 1)Tree Ring and C14 Dating
How does the radiocarbon dating method work? (The Biblical Chronologist, Vol. 5, No. 1)
Radiocarbon WEB-info Radiocarbon Laboratory, University of Waikato, New Zealand.