Method of historical dating
The pre-enlightenment understanding of our geological and cultural history may now be proven wrong and subject to ridicule, but the principles of defining our place in time in the cosmos underpin many sciences.
As technology advances, so do our methods, accuracy and tools for discovering what we want to learn about the past.
For example, a tree ring pattern may show lower growth during a volcanic eruption.
But they can also show human intervention such as when woodland was cleared to make way for agriculture (6).
These energy levels are measured against what they should be if they had not been interfered with and we are able to obtain a date of the intervention.
This is used in archaeological and anthropological contexts (7) in areas where radiocarbon dating is problematic such as dating post AD1700 and where dates from RC14 is anomalous or lacks data. Potassium-argon dating: Typically used in geology and geochronology, K-Ar dating has a minimum age of around 100,000 years ago (but can be problematic when examining material close to this earliest date) up to a top end of around 4.5 billion years.
Amino acid dating: This relatively new form of absolute dating is useful in archaeology, anthropology, paleobiology, molecular biology and anything else that may study organic substances to pinpoint an actual date or define a date range.
It's found a great use in the tracking of human migrations in antiquity, demonstrating earlier arrival of humans into North America - pushing dates back from 15,000 years to 50,000 years (4).
No system is completely failsafe and no method completely correct, but with the right application, they can and have aided researchers piece together the past and solve some of their discipline's most complex problems.The second is water deposition which essentially “freezes” that magnetic particle in places (5).The method is not as limited as we might think; it's been a vital method for some 70 years in discovering dates for ancient archaeological/anthropological deposits. Dendrochronology/Herbchronology: Dendrochronology is the study of tree ring growth and comparing a sequence to an accumulated database to come up with precise dates for events.Similarly, herbchronology examines the growth rings in perennial plants other than trees to come up with the same information.Such rings can tell us the year the plant or tree was cleared; it can also shed light on geological or environmental events that alter the environment.