@ninja_matty69, you try to bring out difficulties in dendrochronology, but your "reasons" why it shouldn't be trusted are laughable.
" imagine counting several thousands pieces of very very thin paper (sometimes several times thinner than paper remember) all bunched together." Yeah, that's fairly easy to imagine; easier, in fact, than imagining 2 million pixels on an HDTV being counted 60-240 times every second. Computers are amazing aren't they?
"They no doubt have to check hundreds of tree remains." Yes, they do. And they do just that.
"but find links all the way back to 2500 bc is going to be very difficult." It is difficult; that's why professionals spend years and years doing it. Thanks for acknowledging their hard work.
"Not only this but they have to be from the region in question. Its no good comparing a tree sample from egypt with one from england. completely different climates will lead to completly different tree rings." Right again. That's what they do.
"Firstly multiple tree rings can occur in wet years. So now you've managed to match your super thin lines with dozens of other trees and your sure mind that you have not made a mistake (after all one half a milimeter ring is totally different from another half a milimeter ring) have you factored this in?" Yes, they do factor that in.
Did you even bother to read about the subject? Here, let's consult wikipedia real quick:
"Trees from the same region will tend to develop the same patterns of ring widths for a given period. These patterns can be compared and matched ring for ring with trees growing in the same geographical zone and under similar climatic conditions. Following these tree-ring patterns from living trees back through time, chronologies can be built up, both for entire regions, and for sub-regions of the world. Thus wood from ancient structures can be matched to known chronologies (a technique called cross-dating) and the age of the wood determined precisely. Cross-dating was originally done by visual inspection, until computers were harnessed to do the statistical matching.
To eliminate individual variations in tree ring growth, dendrochronologists take the smoothed average of the tree ring widths of multiple tree samples to build up a ring history. This process is termed replication. A tree ring history whose beginning and end dates are not known is called a floating chronology. It can be anchored by cross-matching a section against another chronology (tree ring history) whose dates are known. Fully anchored chronologies which extend back more than 11,000 years exist for river oak trees from South Germany (from the Main and Rhine rivers) and pine from Northern Ireland. [1] [4] [5] Furthermore, the mutual consistency of these two independent dendrochronological sequences has been confirmed by comparing their radiocarbon and dendrochronological ages. [6] Another fully anchored chronology which extends back 8500 years exists for the bristlecone pine in the Southwest US (White Mountains of California). [7] In 2004 a new calibration curveINTCAL04 was internationally ratified for calibrated dates back to 26,000 Before Present (BP) based on an agreed worldwide data set of trees and marine sediments. [8] The part of the new calibration curves that relies on tree-ring evidence (IntCal04) dates back to 12,410 calendar (cal) yr B.P. Beyond that and back to 14,700 cal yr B.P., IntCal04 is mainly constructed from 14C dates of foraminiferas from Venezuela's Cariaco basin that are corrected for a constant reservoir age of 405 years. [9]
Your final "point" is irrelevant, because they don't use dendrochronology to confirm building dates, they use it to cross-referrence C-14 samples of the wood itself. Regardless of when the wood was used to build something, they can check how old it is.
