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Kaal posted:Apparently in geology they’re a fan of BP or Before Present. It’s not really standardized (and 74 After Present doesn’t make any sense) but they like setting the origin point at 1950 because that’s when atomic testing started changing the ambient radiation levels that get used for dating prehistoric rock samples and objects. There’s certainly worse time scales. also known as 'before physics'
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Apr 16, 2024 04:37
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Kaal posted:I suspect part of the appeal is the sciencey element of relating your calendar and your archeological work to radiometrics. If you’re using carbon dating and providing the error margin then BP can be useful to clarify that’s what you’re doing. Though in truth, BP has only a limited relationship with carbon dating since the atomic testing had no impact on carbon decay that I’m aware of. On the other hand, if you’re relying on other evidence to establish an object’s age, or if you want to talk about a specific date, then other calendars are probably more appropriate. Carbon dating was hugely impacted, there's a LOT more c14 now and that's why low background steel is valuable
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Apr 17, 2024 17:23
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Kaal posted:The bombs added carbon-14 to the air, and industrialism has diluted the atmosphere with carbon dioxide, but the actual decay rate remains unchanged. As a result those levels are returning to a baseline, and within a few decades the relationship between carbon dating and the bomb testing will essentially end. Thr concentration was abruptly doubled due to bombs, which means that you can actually date ringless trees based on when the c14 shows up in their tissues Nessus posted:Does it affect the really old samples or is it more like you can't reliably carbon date things from after when the nuke tests started It only gets added to living tissues, then starts decaying. Previously atmospheric levels were constant and thus living tissue held an equilibrium, with levels dropping once atmospheric carbon was no longer mxied in. anything living after nuke tests has elevated levels (thus Before Present, since everything that died after that point is no longer reliable. Just blindly putting carbon levels into the previously valid formula would give a negative age)
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Apr 17, 2024 18:05
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The existence of a state is predicated upon securing the power to hurt and kill people.
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May 8, 2024 23:36
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cheetah7071 posted:For Carthage in particular, I had heard the theory that since the remains were almost exclusively babies, that this possibly wasn't killing living babies in sacrifice, but dedicating the victims of natural infant mortality to the gods. Does that possibility remain open with current research? It doesn't seem particularly likely
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May 9, 2024 20:02
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