Quote:
Originally Posted by Calgaryborn
I don't believe Scientist are anywhere near "absolute dating" as you
call it. All the methods used are based on assumptions. The link below identifies three assumptions that have to be made in order to 'believe"
the accuracy of these dating methods: 1. The intial condition of the subject 2. The system has been closed(no change to its enviroment)
3. The radioactive decay rate has remained constant.
http://www.answersingenesis.org/crea...adioactive.asp
I could find many examples of failures using carbon 14 dating because
it has been used on objects we can date historically. Presumably the cause has been enviromental contamination. Yet it is assumed that these other methods which can't be verified are reliable. |
Radio carbon dating has been tested and is accurate. It has been calibrated with many different things that we know the age of. Tree ring data for example (which gives a nearly exact calendar for more than 11,000 years back), and historical objects where the age is known like the Dead Sea scrolls, wood from Egyptian tombs, etc. It is also consistent with other forms of dating. C-14 dating has been calibrated to 30,000 years by using uranium-thorium dating of corals, to 45,000 yeas ago by using lead-thorium dates of glacial lake varve sediments, and to 50,000 years ago using ocean cores from the Cariaco Basin which have been calibrated to the annual layers of the Greenland Ice Sheet. Care to explain how all of these unrelated methods can all produce consistent dates independantly?
1. They've known since 1969 that the dating has to be calibrated for the initial condition of the subject. So they calibrate it by determining the C-14/C-12 ratios at various times in the past.
2. No system is closed (even in a perfect lab condition), so scientists don't just assume the system is closed.
- Many rocks approximate a closed system so closely that various radiometric dating methods produce results to within 1% of each other. Just because some rocks may not be "closed", that doesn't mean none of them are.
- When testing a rock, if they test multiple minerals and they all agree within a few percent, the rock isn't contaminated. It's unlikely that multiple minerals are contaminated in different ways that all happen to come up at the exact same date.
- They go to great lengths to minimize the potential for contamination.
- They can use Isocron methods to find contamination. For example two isotopes of uranium decay into seperate isotopes of lead. In a closed system, plotting the ratio of the two different decay pairs will correlate. If it's contaminated, the plot will be off (since one ratio will differ from the other). http://www.talkorigins.org/faqs/isochron-dating.html
3. Are you going to question gravity next? Or maybe the speed of light? Do you have anything to support an outrageous claim like "radioactive decay rate isn't consistent"? It's amazing to what lengths creationists will go to create FUD.
However, I will still answer it. Radioactive decay can be predicted from first principles from quantum mechanics. Quantum mechanics is the most successful theory ever, your quality of life depends on it every single day.
For radioactive decay to change, fundumental constants of the universe would have to change. If they were changed to allow for a young earth with observed decay rates, then the earth would be a ball of molten slag due to heat.
Not only that, measurements of radioactive isotopes can be taken from supernovae and decay rates measured. Measurements from supernova SN1987A and SN1991T are consistent with current measurements, which means rates haven't changed for between 169,000 years and sixty million years, and even measurements from supernovae billions of years away show no change.
You make it sound like there's one or two scientists making all kinds of assumptions, when in reality there's hundreds of thousands of scientists from dozens of different disciplines (geology to astronomy to physics to biology to antropology) all testing these theories every single hour of every single day, trying to disprove them in any way they can (doing so would be an instant Nobel prize for some of them).