Radiocarbon dating stuff works
This may be tied in to the declining strength of the magnetic field. Carbon dating is a variety of radioactive dating which is applicable only to matter which was once living presumed to be in equilibrium eating the atmosphere, taking in carbon dioxide from the air for photosynthesis.In Libby moved to the University of Chicago where he began his work on radiocarbon dating.
The Earth's magnetic field varies all the time, by both strength and orientation.
Australia should, too, the researchers say, but the droppings of ancient marsupials just haven't turned up. In addition, a sample a standard activity is measured, to provide a baseline for comparison.