How accurate is Carbon 14 dating?

This is absolute non-sense. As we learn more, scientific knowledge expands and changes. IIRC there is no theory in science that has not changed since it's inception. It's a bit ridiculous to claim that this process is wishy washy. The primary reason is to validate theories and such. I mean, at one point we believed that the earth was the center of the universe. When knowledge and more advanced ways of thinking came to light this paradigm was over thrown-and rightly so.

 

We are going to have to mention the
half-life of Carbon-14 sooner or later

 

A fresh apple from the corner drugstore would be undateable by carbon 14 method. Why? Because ever since the industrial revolution we have contaminated all the earth's carbon dioxide with carbon taken from drilled oil and mined coal. This makes for carbon that has been in the ground long enough there aren't any radioactive atoms left. On the other hand, atmospheric nuclear reactions add carbon 14 atoms back in. But these processes obviously mess up the method. So it only works for items buried and kept intact from before the industrial revolution. This includes tree rings within the tree trunk, but definately rules out the apple in the grocery store.

 

You are right. Since I do not think that the half-life has been changing, I will let someone else promote that. Following one of Helen's links to her husband's website is one place to get information if you want to take that route.

I'll post the following. Go to http://www.nobel.se/chemistry/laureates/1960/libby-lecture.pdf and look at figure 3 on page 9. You will see a chart plotting the age of items of known age (Some bread from Pompeii is one point. We know not just the day but the approximate time of day for that one.) against the dates determined from C14. Going back 5,000 years shows the method working well over that time period.

 

Here's a site to a location that explains a lot about carbon 14 dating and how it is calibrated.

The original developers of carbon 14 got useful data on the assumption carbon 14 levels were constant in the past. The calibration by use of known aged carbon bearing organic matter allows the age determinations to be more precise. This is the normal way science progresses.

Note that bristlecone pine annual rings alone go back 11000 years. I don't know of any YEC theories that allow for that. But hey, annual rings are annual rings!

The carbon 14 method allows dates to be determined far earlier than 11000 years. Now that mass spectrometers are used to count individual atoms from the sample, they can get results back as far as 50,000 years.

Edited post 5/19 to actually put the site in! (blush)

http://unmuseum.mus.pa.us/radiocar.htm

[ May 20, 2003, 02:03 AM: Message edited by: Paul of Eugene ]