Black Tin Method and Helium Method
Black Tin Method
Uranium and thorium change to be tin through a radioactive process. The change can be determined, that is from 1,000 kg of uranium and 0,0001 gram of black tin. In one year, uranium 238 changes through levels to be black tin 206 and thorium 232 to be black tin 208.
In that change it is also formed the elements of helium. Based on the amount of helium elements formed, it can be known the period of radioactive process happens. According to calculation of A. Holmes in 1946-1947. The age of Earth’s shell since Cambrian age is at least 3,350 million years. Commonly it can be accepted the age of Earth is 4,5 million years, while the age of galaxy is more than 10 billion years.