Materials can radiocarbon dating used
We know (from other measurements) that the Sun hasn't fluctuated by more than 10 percent in the last million years.However, even this small an adjustment was a bit of a shock.On the Web, you could visit a dating laboratory, visit a dating service, read an encyclopedia entry or read a critique.The Lake Suigetsu varve calibration was reported by ABC News and was published: Atmospheric Radiocarbon Calibration to 45,000 yr B.As the name suggests, fossil fuel is old, and no longer contains C14.Both of these man-made changes are a nuisance to carbon dating.
For example, see Radiocarbon 46,1029 (2005), which has a calibration curve that goes back 26,000 years.
For example, Stonehenge suddenly became older than the Pyramids, instead of younger.
Since then, several other calibrations have been done, which confirm and extend the tree-ring one.
Some corals can be carbon dated, and also dated by another radioactive material, Thorium-230.
Pollen found in the Greenland icecap has been carbon dated, and also dated by counting ice layers. Trees grow a thick ring in a good year, and grow a thin ring in a bad year.