Ratio used in carbon 14 dating
Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California.Its existence had been suggested by Franz Kurie in 1934. The primary natural source of carbon-14 on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide.Outside the range of recorded history, calibration of the 14 clock is not possible.This means the above calculations are only evolution speculation and NOT backed up by real science.Think of it like a teaspoon of cocoa mixed into a cake dough—after a while, the ‘ratio’ of cocoa to flour particles would be roughly the same no matter which part of the cake you sampled.The fact that the C doesn’t matter in a living thing—because it is constantly exchanging carbon with its surroundings, the ‘mixture’ will be the same as in the atmosphere and in all living things.
In fact, the whole method is a giant ‘clock’ which seems to put a very young upper limit on the age of the atmosphere. As soon as a living organism dies, it stops taking in new carbon.The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced.Other useful radioisotopes for radioactive dating include Uranium -235 (half-life = 704 million years), Uranium -238 (half-life = 4.5 billion years), Thorium-232 (half-life = 14 billion years) and Rubidium-87 (half-life = 49 billion years).The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy.
However, radioisotope dating may not work so well in the future.