TLDR: High cosmic ray events cause uptick in atmospheric carbon-14. This is deposited in yearly growth rings of trees and can be used as global alignment points for tree ring dating.
Researchers accurately dating a 7k-year-old settlement using cosmic rays
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Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#12Earlier quoted context omitted.
I remember a while back someone managed to build a many hundred year sequence of growth rings by analyzing all of the incremental construction in one town and aligning tree rings from one piece of wood with the same rings in newer or older pieces, using software not unlike reassembling DNA fragments, but with growth rings.
The maximum is not just many hundred years. The Hohenheimer Jahrringkalender based on pine trees of central Europe goes back 12,460 years and people are working on extending it backwards another 2,000 years.[1] Such calendars are anchored in the present and require an unbroken backward chain of quality wood samples from the same region and the same tree species. The advantage of the new method based on Miyake events…
The number I thought I remembered sounded ridiculous in my head so I underpromised, as it were.
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#13At first I was a bit confused why this was a big deal given that Cosmogenic Radionuclide Dating[1] (which is based on cosmic rays) has been a thing for a while. But it turns out this uses an entirely different cosmogenic method based on atmospheric carbon (combined with Dendochronology from the tree rings). Very cool!
[1]: https://en.m.wikipedia.org/wiki/Surface_exposure_dating
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#14I've never dated a settlement myself, but the conversation must be awful.
Common goals is the key. You have to be ready to settle down.
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#15Sorry but what's the difference between this and C14[1] dating?
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#16> using cosmic rays
How did they generated them ?
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#17Sorry but what's the difference between this and C14[1] dating? [1]: https://en.wikipedia.org/wiki/Radiocarbon_dating
The innovation is to find traces of a global cosmic-ray event with which to connect the dating of objects in one local area, Greece, where the dendrochronological data is not continuous, with those in far away local areas, for example England/Ireland, where we have continuous dendrochronological data
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#18> using cosmic rays How did they generated them ?
There's an endless supply of organic, free range cosmic rays that rain down from the sky. They've been scientifically useful in many ways, not just this one.
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#19Sorry but what's the difference between this and C14[1] dating? [1]: https://en.wikipedia.org/wiki/Radiocarbon_dating
Accuracy. Using carbon dating for things that long ago gives you only a rough idea. Counting tree rings is precise, but tree ring chronologies are relative, unless they can be continued to the present or anchored to an event with a known date. These researchers did the latter, using a global and well-dated Miyake event.
Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays
#20Earlier quoted context omitted.
I remember a while back someone managed to build a many hundred year sequence of growth rings by analyzing all of the incremental construction in one town and aligning tree rings from one piece of wood with the same rings in newer or older pieces, using software not unlike reassembling DNA fragments, but with growth rings.
I don't know about the rest of the world, but in the UK dendrochronology is widely used for dating wood structures. In England they have a database that can date (some) trees back basically to any time of human existence in England. In Ireland their data goes back before 5000 BCE. Thanks Time Team. :)
Time team's great, glad to see them back.