Carbon 14 Dating

[notnutnut]

Hi, I've spent 2 hours trying to find the answer to this;how accurate is carbon 14 dating as a method of determining the age of a tree aged at most 150 years at most,any help please boffins would be most appreciated,thanks all !

[Mosaic]

Not very. The calibration date for C14 measurement is taken as C14 levels in 1950, so it's already 63 years out before you've started.
The cost of using C14 to provide this date would be prohibitive unless you are flush with cash.
A piece of wood of that date could be securely dated by its context - where and with what it was found for example - or by its style if carved, or by comparison with tree ring samples (dendrochronology) if big enough to display these.
Why so you need to use absolute dating on the sample?

[jake-the-peg]

You say tree - do you mean a living tree?

If so you can't use radiocarbon dating at all.

The whole system is based on the fact that living organisms take in a mix of radioactive and non radioactive carbon and when they die the proportion or radioactive carbon drops as it decays.

Carbon dating will only give you the age from when something died

(and I do hate the term "boffin!" :c) )

[mibn2cweus]

//(and I do hate the term "boffin!" :c) )//

. . . possibly a bit more acceptable than egghead, nerd, or geek. ;o)

http://en.wikipedia.org/wiki/Boffin

[Teddio]

It may be possible to extract a core and then count the rings. The heartwood of the tree is effectively devoid of living cells and therefore the ratio of C14 to C12 will decrease exponentially.

The outer layers of the tree are living, therefore the ratio of C14 to C12 will be constant.

If the age of a tree is defined as the age of the (dead) central heartwood then it is hypothetically possible to use C-14 dating. However the percentage uncertainty in the calculated age would be large for such a young sample.

[Peter Pedant]

I have always been surprised at how inaccurate it is.
The Turin Shroud , carbon dating gave the answer - it was nt AD 30
but the 95% confidence interval was 1260-1390 - the difference is 130 wh implies it is useless for your tree

wh isnt dead etc etc

so I would count tree rings

[notnutnut]

Thank you all for your help on this,I still don't grasp why this method is exclusive to only dead samples though ?Luckily my dilemma has been resolved by simpler methods though that should resolve my dating needs,again,thank you all !

[notnutnut]

MIBN2CWEUS,I checked on your link to 'Wiki'and surely the term is complimentary rather than denigratory (thanks anyway)