Radiometric dating--the process of determining the age of rocks from the decay of their radioactive elements--has been in widespread use for over half a century.
There are over forty such techniques, each using a different radioactive element or a different way of measuring them.
Archeology is the scientific study of past human culture and behavior, from the origins of humans to the present.
Archaeology studies past human behavior through the examination of material remains of previous human societies.
Obsidian has been quarried and traded by western Melanesians since at least 19,000 bp, with the earliest-used and most important source being that at Talasea on CATEGORY: geology DEFINITION: The absorption of water on exposed surfaces of obsidian.
In each specific environment, the surface of an obsidian artifact absorbs water at a steady rate, forming the hydration layer. If the local hydration rate is known and constant, this phenomenon can be used as an SYNONYMS OR RELATED TERMS: obsidian hydration layer dating, obsidian dating CATEGORY: technique DEFINITION: A method of dating in which the age of an obsidian artifact is established by measuring the thickness of its (layer of water penetration) and comparing that to a known local hydration rate.
is a structure whose outer surfaces are triangular and converge to a single point at the top, making the shape roughly a pyramid in the geometric sense.
This distribution of weight allowed early civilizations to create stable monumental structures.The largest pyramid by volume is the Great Pyramid of Cholula, in the Mexican state of Puebla.For thousands of years, the largest structures on Earth were pyramids—first the Red Pyramid in the Dashur Necropolis and then the Great Pyramid of Khufu, both of Egypt, the latter is the only one of the Seven Wonders of the Ancient World still remaining.These remains include the fossils (preserved bones) of humans, food remains, the ruins of buildings, and human artifactsitems such as tools, pottery, and jewelry.From their studies, archaeologists attempt to reconstruct past ways of life.