The carbon dioxide gas produced is run through an accelerator mass spectrometer, which measures the decay of radioactive carbon 14 – the more the carbon 14 has decayed, the older the object is.Comparisons are also made with the amounts of C-14 expected to have existed in the atmosphere in the past.And what’s unique about “Marvin’s Machine” is that it has five chambers, so multiple samples can be tested at once. “To my knowledge, nobody has gotten more than one plasma running at one time.”The Archaeology Institute of America’s Archaeology magazine named Rowe’s non-destructive dating method one of the Top 10 discoveries of 2010.It noted that he has refined the method to work on objects coated in sticky hydrocarbons, such as the resins that cover Egyptian mummy gauze.“Archaeologists, meanwhile, are hailing the discovery as one of the most important in decades, particularly for issues surrounding the repatriation of human remains from Native American burials, which modern tribes don’t want to see harmed,” said the magazine.In Rowe’s non-destructive method, an entire artifact goes into in a vacuum chamber with a plasma.The gas gently scrubs or oxidizes the surface of the object to produce carbon dioxide – CO2 – for the C-14 analysis, without damaging the artifact.“We can energize the plasmas so that they are really hot, but we can also tune them down so they are extremely gentle,” Blinman said as Rowe and his crew fired up their machine to test the bison tooth and sheep bone.
(Eddie Moore/Albuquerque Journal)Marvin Rowe, a scientist at the New Mexico Office of Archaeological Studies, adjusts the Low Energy Plasma Radiocarbon Sampling device he built to date artifacts with minimal damage. That machine he built, and what it’s used for, helped Rowe win the prestigious Fryxell Award for Interdisciplinary Research from the Society of American Archeology two years ago.“We call the process Low Energy Plasma Radiocarbon Sampling,” said New Mexico’s state archeologist Eric Blinman, who credits Rowe with inventing the process.Rock art pigments don’t have that much carbon in them.But “Marvin’s Machine” can date material 100 millionths of a gram or less.Blinman explained that Rowe’s alternative process is based on plasmas – ionized gas made up of groups of positively and negatively charged particles, and one of the four fundamental states of matter, alongside solid, liquid and gas.
Plasmas are used in television displays and in florescent lights, which use electricity to excite gas and create glowing plasma.“But, in the United States at least, most of the paintings are not charcoal.