|Atomic mass||12 amu|
|Date of discovery||Carbon has been known since ancient times.|
|Name of discoverer||Unknown|
|Name origin||From the Latin carbo.|
|Obtained from||Incomplete combustion.|
It has been suggested that the C-14 decay rate varies proportionately with the age of the universe, and if that age is, say 5,000 years rather than 10 billion years, then the C-14 decay rate could have been many orders of magnitude larger a thousand years ago.