carbon-14 dating question

[sabianq]

so i am trying to figure out if carbon dating can be used to date material as young as 5 years or so.

does anybody have any idea as to the accuracy of carbon dating?

thanks

[Ronald Brak]

so i am trying to figure out if carbon dating can be used to date material as young as 5 years or so.

Technically you could, but I don't think it would be practical. You would need extremely precise measurements to detect the tiny difference in carbon 14 levels that would occur over five years.

does anybody have any idea as to the accuracy of carbon dating?

It's pretty good. There's a good chance it will be correct to within a hundred years for samples less than 10,000 years old. Accuracy is limited both by the precision of the instruments used and how good a record we have of past levels of carbon 14 in the atmosphere.

[antoniseb]

so i am trying to figure out if carbon dating can be used to date material as young as 5 years or so.

Carbon 14 is created in the atmosphere from cosmic rays and nitrogen. It gets into organic matter by being absorbed from the air by *something*. But depending on what you are measuring, you might not be very certain of the duration of how the Carbon got into the material you are measuring. We can know precisely how much Carbon14 there is in a sample, and we can know from that the average amount of time ago that the Carbon was formed in the atmosphere to great precision, but that doesn't usually tell us the age of the object in question to within five years.

[suntrack2]

I found 2 interesting links regarding your querry, sabianq.

here are the links:

http://www.cs.unc.edu/~plaisted/ce/dating.html

http://www.creation-science-prophecy.com/C14fp.htm

[NEOWatcher]

I found 2 interesting links regarding your querry, sabianq.

Interesting, maybe (as long as you're blood pressure is in check).

They are both creationist articles meant to cast doubt on C14 dating. I'm not sure they are too fair in thier assesment.

[Fazor]

The only thing I know about carbon-14 dating is to be sure to have her home by 9:00, and to not try any "funny stuff" until she's at least carbon-18.

[NEOWatcher]

The only thing I know about carbon-14 dating is to be sure to have her home by 9:00, and to not try any "funny stuff" until she's at least carbon-18.

I guess that's why carbon-12 dating is out of the question.

[Amber Robot]

The only thing I know about carbon-14 dating is to be sure to have her home by 9:00, and to not try any "funny stuff" until she's at least carbon-18.

Of course by then she will have put on a lot of weight and become incredibly unstable, so perhaps you might not be interested in dating her anymore.

[sabianq]

ok, thanks for the information.
but i am confused about something here.
I was in the car with a friend on mine and we were listening to NPR when a story about the Anthrax attack came in about a person of interest killing himself with a bucket of Tylenol. but when in the report went on to say that radiocarbon dating was used by the FBI to determine the age of the Anthrax, I had a moment of pause because i had always thought that radiocarbon dating was not accurate enough to determine the age of any organic that was less than 30 years old or so.

http://news.bbc.co.uk/1/hi/world/americas/2062325.stm
"The FBI used radiocarbon dating to establish the age of the anthrax, which had been sent to the US Congress and prominent media figures. "

and here
http://www.gainesville.com/article/2...thrax_Evidence

"By calculating the ratio of carbon-14 to the normal kind in residue of plants eaten by the cow from which the broth was made, investigators learned by June 2002 that the anthrax had been grown within the last two years."

also cited here:
http://www.propublica.org/article/my...ks-solved-805/

I just have to wonder if the FBI can actually cite evidence such as radiocarbon dating to determine the age of a substance as admissible evidence in a trial when the limits of the test seem dubious when dealing with such tiny time frames.

Needless to say, we discussed it and decided to see if radiocarbon dating can actually be used to determine the age of an organic that is as new as 10 years.

I did do some cursory research and there seems to be an error factor of +- 40 years.

http://en.wikipedia.org/wiki/Carbon_..._note-nosams-6

"In 2008, a typical uncertainty better than ±40 radiocarbon years can be expected for samples younger than 10,000 years."

the two statements in bold shown above suggest that either someone is using a cool new technology or the statement is false.

could there be another explanation?

[ToSeek]

Moved from OTB to Q&A.

[sabianq]

^^^^^ I had place this thread in OTB because i was to understand that the Q&A board was mainly for space and astronomy questions.

[Fazor]

Moved from OTB to Q&A.

Hey, no fair. I wouldn't have injected non-helpful un-solicited humor (or my humble attempt at it) to a thread in Q&A!

[jfribrg]

I found 2 interesting links regarding your querry, sabianq.

here are the links:

http://www.cs.unc.edu/~plaisted/ce/dating.html

http://www.creation-science-prophecy.com/C14fp.htm

As others have mentioned, these are creationist arguments. Obviously, they are not scientific ( whenever you start with the conclusion, it isn't science). I have encountered these pages before, and I wonder what is the rebuttal to these arguments, especially concerning the uncertainty about the C14 levels in the past and the leaching of elements into the old rocks etc.

[BioSci]

could there be another explanation?

Yes, due to the atomic testing in the 50s and 60s, the the level of C14 spiked dramatically and allows for an alternative calculation based on absolute level of C14 related to year of formation see an example and graph in the Wikipedia article: http://en.wikipedia.org/wiki/Radiocarbon

One side effect of the change in atmospheric carbon-14 is that this enables the determination of the birth year of an individual: the amount of carbon-14 in tooth enamel is measured with accelerator mass spectrometry and compared to records of past atmospheric carbon-14 concentrations. Since teeth are formed at a specific age and do not exchange carbon thereafter, this method allows age to be determined to within 1.6 years. This method only works for individuals born after 1943,[11][12] and it must be known whether the individual was born in the Northern or the Southern Hemisphere.

[sabianq]

Yes, due to the atomic testing in the 50s and 60s, the the level of C14 spiked dramatically and allows for an alternative calculation based on absolute level of C14 related to year of formation see an example and graph in the Wikipedia article: http://en.wikipedia.org/wiki/Radiocarbon

thank you sir.
That is what i was looking for.
http://news.nationalgeographic.com/n...ke_body_2.html

[01101001]

I just have to wonder if the FBI can actually cite evidence such as radiocarbon dating to determine the age of a substance as admissible evidence in a trial when the limits of the test seem dubious when dealing with such tiny time frames?

That seems to me to be: without a doubt they can. The prosecution can provide expert testimony that the conclusions are legitimate and the defense can provide counter-experts. It's an adversarial process. The decider of fact can do its job and decide.

But, of course, it becomes much more simple and effective to cite the evidence to the press when there will be no trial. Both sides have been making arguments to the press and their readers.

[mugaliens]

Hey, no fair. I wouldn't have injected non-helpful un-solicited humor (or my humble attempt at it) to a thread in Q&A!

I'm kind of glad ToSeek moved it. OTB really is a lot of babbling, but Q&A really is about questions. Perhaps the Q&A guidelines might be expanded from "space and astronomy" to "science."

[slang]

As others have mentioned, these are creationist arguments. Obviously, they are not scientific ( whenever you start with the conclusion, it isn't science). I have encountered these pages before, and I wonder what is the rebuttal to these arguments, especially concerning the uncertainty about the C14 levels in the past and the leaching of elements into the old rocks etc.

I couldn't bring myself to wade through those pages, but start here to see if anything applies. Maybe search for carbon.

[Metricyard]

I'm kind of glad ToSeek moved it. OTB really is a lot of babbling, but Q&A really is about questions. Perhaps the Q&A guidelines might be expanded from "space and astronomy" to "science."

Wouldn't it be more logical to move the Q & A to the Space & Astronomy section and move the general science to the general section? I think it would avoid a lot of the confusion of what belongs where.

[antoniseb]

Wouldn't it be more logical to move the Q & A to the Space & Astronomy section and move the general science to the general section? I think it would avoid a lot of the confusion of what belongs where.

No matter what system you employ, SOME posts will be in the gray area. I thought General Science or Q&A were the two best options, but OTB wasn't really out of bounds. No one should spend a lot of energy worrying about where this landed or should land. I think the Cosmic Ray aspect made Q&A more legit. I respect other analysis, but a choice had to be made.

[Drunk Vegan]

the two statements in bold shown above suggest that either someone is using a cool new technology or the statement is false.

could there be another explanation?

Rule #1 in any job : Cover your own behind.

If you're going to say you've solved the anthrax mystery, you've got to be * very specific *. If that means throwing out "radiocarbon dating" as your source of evidence, that'll be good enough to satisfy most people and your job is secure.

[Metricyard]

No matter what system you employ, SOME posts will be in the gray area. I thought General Science or Q&A were the two best options, but OTB wasn't really out of bounds. No one should spend a lot of energy worrying about where this landed or should land. I think the Cosmic Ray aspect made Q&A more legit. I respect other analysis, but a choice had to be made.

No problem, it was just a suggestion. Not trying to accuse anyone of anything. Back on topic.

After reading some of the Antrax/FBI links provided, I am a bit skeptical of their conclusions. From this link taken from above,

Analyzing traces of the beef broth used to grow the anthrax, scientists measured carbon-14 left from nuclear weapons tests in the 1950s, whose quantity diminishes every year.

By calculating the ratio of carbon-14 to the normal kind in residue of plants eaten by the cow from which the broth was made, investigators learned by June 2002 that the anthrax had been grown within the last two years

Either this is just poor writing, or my old age is finally catching up to me, but I can't for the life of me follow what the heck is trying to be said here.

I hope that more information on this is forthcoming.

[BioSci]

No problem, it was just a suggestion. Not trying to accuse anyone of anything. Back on topic.

After reading some of the Antrax/FBI links provided, I am a bit skeptical of their conclusions. From this link taken from above,

Either this is just poor writing, or my old age is finally catching up to me, but I can't for the life of me follow what the heck is trying to be said here.

I hope that more information on this is forthcoming.

That article is rather unclear but the science of C14 dating is not that difficult - just a bit complex when one includes the results of recent atomic testing (1950s and 60s).
Normal C14 dating is based on the simple idea that atmospheric C14 concentration is rather constant as a result of cosmic ray production of C14 and the decay half time of C14 of 5730 years resulting a fairly constant level of C14 of ~ 1 part per Trillion (ppt) of C14 in the atmosphere which then decays in fixed materials over time [for better accuracy, calibration curves for actual C14 concentrations can be used]. This works fine for carbon sources before 1955 and results in estimated dates of maybe +/- 100 years.-
But after 1955 the level of C14 in the atmosphere was significantly increased as a result of atomic bomb testing such that by ~1965 the level of C14 in the atmosphere nearly doubled. This significant increase in atmospheric C14 also means that by measuring the % of C14 in an organic sample from after 1955 one can determine the year that the carbon was 'fixed' from the atmosphere (by plants) to a very high accuracy (~1.6 years) since the concentration of C14 in the atmosphere varied so dramatically compared to the longer half-life of C14 and the historical concentration of C14.

see for example: http://www1.phys.uu.nl/ams/Radiocarbon.htm