alt Hacker NewsIs my understanding of carbon dating needing an update or the precision to distinguish 100y difference on a 1.2k to 1.3k years base not enough?
If 100y is the difference it could just be that the tree grew for 100y and the at the end they used it?
Replies
ggm • today at 7:14 AM
Wood stored underwater is a thing. Lots of places use bog wood, drowned trees. Down deep, it just goes on being wood.
Tree ring databases are pretty good. I think they cross calibrate to radio carbon maybe.
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internet_points • today at 7:11 AM
Most likely they used trees that had grown for at least 100y, as that's how you get the hardest wood (wood from young trees gets all bent in humid weather)
That is not an issue, because the tree will have been absorbing freshly made atmospheric carbon-14 until it died, at which point it starts to decay into carbon-12. So carbon-14 dating pinpoints the time of death, if you get the methodology right. We apparently now use accelerator mass spectrometers to just outright count all the atoms of c-14 and c-12. But in the 70s c-14 dating was notoriously tricky and full of pitfalls to with calibration and contamination and estimation, and it looks like we've only reduced the last of those possible sources of errors, the need for estimation, and the rest of it is still sketchy.