Firstly, Comet Halley has a variable orbital period of [around] 76.5 ± 2.5 years.
Halley’s orbital period over the last 3 centuries has been between 75–76 years, although it has varied between 74–79 years since 240 BC.
Gunnar Heinsohn very politely points out the 700 years between the 230s and 930s AD “have neither strata nor tree samples”.
Therefore, some 700 years of the 1st millennium (230 to 930s) have neither strata nor tree samples for C14 or dendro-chronological dating.
Archaeological Strata Versus Baillie’s Tree-Rings: Proposal for an Experiment
Gunnar Heinsohn – 8 Sept 2014
http://www.q-mag.org/_media/gunnar-strata-vsbaillie08-09-2014.pdf
Halley’s orbital period over the last 3 centuries has been between 75–76 years, although it has varied between 74–79 years since 240 BC.
Gunnar Heinsohn very politely points out the 700 years between the 230s and 930s AD “have neither strata nor tree samples”.
Therefore, some 700 years of the 1st millennium (230 to 930s) have neither strata nor tree samples for C14 or dendro-chronological dating.
Archaeological Strata Versus Baillie’s Tree-Rings: Proposal for an Experiment
Gunnar Heinsohn – 8 Sept 2014
http://www.q-mag.org/_media/gunnar-strata-vsbaillie08-09-2014.pdf