Questions on Radiocarbon dating?

[eves_child]

How accurate is radiocarbon dating?

What is the time limit on the dating?

How can the earth be dated?

 

[Jet Black]

carbon dating is accurate to about 30k years I think, before drowned out by background noise.

http://earth.leeds.ac.uk/dynamicearth/dating/

 

[eves_child]

A few more questions.

How do you determine what age are the sedimitary layers?

How do you determine ages later than 30k?

Are there more accurate testing processes available besides carbon dating?

Off the topic question,
how do we determine the age of the universe?

 

[Frumious Bandersnatch]

Radiocarbon dating has to be calibrated because of fluctuations in the atmospheric production of C14. It can be calibrated back to about 8,000 years using tree rings and has recently been calibrated back to about 45,000 years using lake varves.

http://www.acad.carleton.edu/curricular/BIOL/classes/bio375/pdfs/c14 calibration.pdf

There are some good resources on the web regarding radiometric dating in general including Radiometric Dating from a Christian Perspective

http://www.asa3.org/ASA/resources/Wiens.html

NASA physicist Tim Thomposon maintains an extensive archive on radiometric dating.

http://www.tim-thompson.com/radiometric.html

The Frumious Bandersnatch

 

[Arikay]

Some good responses (and very good resources). To rehash what everyone already said, Radio Carbon dating is good to around 50,000 years (often shorter, depending on the circumstances) and it used to be good to under 30,000.

In the old Radio Carbon tests (or the traditional method) a date of 30,000 or older was generally considered to mean that the object was out of the range of C-14 dating.

Tree ring dating, and Ice core (i think its Ice Core) dating are other non radiometric dating methods that have been used to validate basic radiocarbon years, and to also calibrate the dating to make it more accurate.

As far as accurate, for the radiometric dating, radiocarbon seems to be the most accurate, but it also has a very small upper limit compared to other methods.

I would suggest reading through the ASA paper in the last post. Lots of great information and it has the plus of being writen by a christian (for the few that think dating is an atheists conspiracy. )

How accurate is radiocarbon dating?

What is the time limit on the dating?

How can the earth be dated?

 

[DrLao]

A few more questions.

How do you determine what age are the sedimitary layers?

How do you determine ages later than 30k?

This is mostly done using other types of radiometric dating. Potassum-argon, Rb-Sr isochron, and uranium series. These three are good back to billions of years.

Are there more accurate testing processes available besides carbon dating?

Over the range of radiocarbon dating? I suppose counting tree rings and ice cores in Greenland or Antarctica would probably be more precise. But you usually can't date what you are interested in with them. They can be used to calibrate radiocarbon dating though.

Off the topic question,
how do we determine the age of the universe?

Two main ways. Determine how old the oldest stars are and figure out how long the universe has been expanding. The first can be determined by what we know about nuclear fusion and stellar evolution. The second can be determined by looking at how fast the universe is expanding now (and in the past) and backtrack to the big bang. It is important to note that the first method puts a lower bound on the age of the universe. The universe can be older than the oldest stars, but it cannot be younger than them.

 

[LaserCool]

I've read in one journal that using mass spectroscopy, which is not affected by background radiation, the upper limit of C-14 has been raised to 70,000 years, with a practical limit with moderately priced lab equipment of about 50,000-55,000 years.

I could look up the citation if anyone's interested.

Also, as stated before there are at least 6 dating methods I'm aware ofwiht half life rates. Realize, a half life is the anount of time it takes for half the sample to decay.

Suppose you started with a sample that udergoes radioactive decay with a half-life of one day. After one day, you have 1/2 your original sample. After two days, 1/4 the sample, three days 1/8, four days 1/16, etc.

The limit of your dating is based upon the smallest sample you can accurately measure.

Radioactive decay chains and thier half-lives:
C-14 --> N-14 5730 years
K-40 --> Ar-40 1,250,000,000 years
Rb-87 --> Sr-87 48,800,000,000 years
Sm-147 --> Nd-143 106,000,000,000 years
Lu-176 --> Hf-176 35,900,000,000 years
Re-187 --> Os-187 43,000,000,000 years

 

[Arikay]

"I could look up the citation if anyone's interested"

Yes please.

 

[eves_child]

Thank you all for you wonderful resources. They have helped me out a lot.Sorry, but I have one more question. How do they determine half lifes?Thank you once again.

 

[Jet Black]

nuclear physics mostly, also you can do it by measuring a pure sample and looking at the amout of radiation it gives off.

 

[eves_child]

Thank you so much for your help. The information has been great. I'm sorry for asking a million and one question, but I want to have the knowledge to make informed decisions or statements. I have so many more questions.
Thanks again for the wonderful information.

 

[Arikay]

Ask away, many here are very happy to answer as many questions as you have.

 

[eves_child]

What is the process for dating bones such as dinosaurs and humans?
I'll think of some more tomorrow. I'm a bit tired tonight.

 

[LaserCool]

"I could look up the citation if anyone's interested"

Yes please.

I coudn't find the exact journal, apparently I'd thrown it out, but I did find some good links on AMS.

A good schematic on how it works

U of Arizona's site

Livermore Lab's site

Arizona claims accuracy in carboniferous samples to 50,000 years.

 

[RickG]

Well, since there seems to be a resurfacing of some old threads, how about this one since the topic surfaces quite often in numerous other threads that are not really targeted toward it.

 

[crjmurray]

Well, since there seems to be a resurfacing of some old threads, how about this one since the topic surfaces quite often in numerous other threads that are not really targeted toward it.

Well go ahead Rick, answer the question.

 

[RickG]

Well go ahead Rick, answer the question.

I'll be delighted. From the OP:

1. How accurate is radiocarbon dating?

It varies with the depth of time and the source type of the sample and expressed as a function of statistical reliability (+/-), either as a percent, calendar years, or carbon years. There are numerous possible variables, but they are always noted and described in the literature. No picking and choosing to fit a desired date as creation science suggests.

What is the time limit on the dating?

Beta counting method requires several grams of sample and generally has an upper limit of 50,000 years. The AMS method only requires a milligram or less sample and can go as far as 100,000 years,

How can the earth be dated?

Not by radiocarbon dating.

 

[crjmurray]

I'll be delighted. From the OP:


It varies with the depth of time and the source type of the sample and expressed as a function of statistical reliability (+/-), either as a percent, calendar years, or carbon years. There are numerous possible variables, but they are always noted and described in the literature. No picking and choosing to fit a desired date as creation science suggests.


Beta counting method requires several grams of sample and generally has an upper limit of 50,000 years. The AMS method only requires a milligram or less sample and can go as far as 100,000 years,


Not by radiocarbon dating.

Go on. There are some follow up questions.

 

[RickG]

A few more questions.

1. How do you determine what age are the sedimitary layers?

Actually there are a number of different methods which include radiometric, non-radiometric, and relative dating. The non-radiometric methods of course are for specific types of sedimentary rock, such as speleothems and varves, although both of those can and are dated radiometrically as well. In fact, speleothems are also helpful in establishing the radiocarbon calibration curve. In other sedimentary rocks, radiometric dating can be used, but not by just dating the rock. What is dated is either a volcanic extrusion layer in the strata or volcanic ash contained within. Both the radiometric, speleothems and varves are absolute dates. Relative dating sedimentary rock is generally what is most misunderstood and erroneously described, especially in the creation science literature as circular reasoning. In fact, there is no circular reasoning. Relative dating of sedimentary strata is by the use of index fossils. That is fossils that are of relatively short duration of their existence, geologically speaking, thousands to a few million years. The common creationist spin is that the fossils date the strata and the strata date the fossils. Thus the circular reasoning accusation. The fact is, in reality, the strata is radiometrically dated in which the fossils are contained. Once the strata is dated, the index fossils that are found in only that specific strata are known to be of a relative age spanning the upper and lower limits of where they are contained in the strata, thus only a relative age spanning thousands to millions of years.

How do you determine ages later than 30k?

There are numerous methods of dating, all of which are unique and applicable to specific applications with specific limits. The last time I counted the methods I was aware of and could describe amounted to over 70 and that number keeps growing with new understanding and technology, not to mention becoming more and more reliable and accurate.

Are there more accurate testing processes available besides carbon dating?

Each method is unique and applicable to specific applications.

Off the topic question,
how do we determine the age of the universe?

By measuring the age of stars, which is out of my expertise.

 

[dad]

How accurate is radiocarbon dating?

It is collaborated by things like tree rings. The trees of Noah's day grew in weeks, so a ring was not yearly, obviously. The nature or forces and laws of Noah's day were likely different also, which means that there may not have been radioactive decay persay at all. Science assumes a same state past nature, in all it's ideas and models and dates. That means they are useless beyond aprox 3500 years or so.

What is the time limit on the dating?

All dating is just belief beyond say about 4000 or so years ago.

How can the earth be dated?

Fortunately we have God's record, and the times when Adam lived more or less.