Posted: Aug 28, 2013 7:33 pm
Transilvanian wrote:http://ncse.com/cej/3/2/answers-to-creationist-attacks-carbon-14-dating
SO what is the explanasion for C14 isotope in millions yrs objects? Because with my English is hard to understand...
In one simple sentence.
Imagine you have 128 dollars in your bank. Every year, you lose half of your money. In one year, you have 64 dollars. In five years you have four dollars. In 10 years you have about 12-13 cents.
At a certain point, there just isn't enough to give exact numbers on the date. In 20 years you have 0.0122 cents. In 25, 0.0003 cents. Now, imagine that in the inital example, you have 128 dollars, but every 2-3 months you gain a penny (it's not a specific rate). Once you start to get 15-20 years away, the new pennys are going to be far more noticable than any of the money remaining from the original 128 dollars, and they are going to make it impossible to be perfectly accurate.
This is why carbon dating cannot be used for very very old things, because at that point most of the original "money" (carbon) has gone, and most of what you're collecting are the new pennys (there is a small amount of C14 decay coming from places other than the fossil). That small amount has almost no effect on the accuracy at first (what is 1 penny compared to 128 dollars?), but over time starts to have a HUGE effect on accuracy after many years (1 penny is a LOT more than 0.0003 cents).
Luckily, when dating things, we can use elements that take a much slower time to decay than Carbon 14. In the example, this would be like halving your money cut every 1 million years instead of every year. This would allow your dating to be accurate for a much longer time than you could when you were losing your money/elements at a faster rate.