Carbon-14 is one form of radiometric test, but one very important feature distinguishes it from the others. Other radiometric tests can be used only in determining the ages of volcanic rocks. Carbon-14 dating, however, can be used to determine the ages of once-living things. That is because Carbon-14 is the only radioactive substance found in the bodies of living organisms.
The Earth is constantly being bombarded by cosmic rays from outer space. These rays strike nitrogen-14, found in high levels in the atmosphere, and transform this into carbon-14, a radioactive substance. Radioactive carbon-14, a newly produced element, combines with oxygen in the atmosphere, forming another radioactive compound, C-14 O2. As we know, plants use CO2 (carbon dioxide), H2O (water) and solar rays in order to produce their nutrients. Some of these carbon dioxide molecules the plant absorbs into its body are molecules formed from radioactive carbon-14. The plant accumulates this radioactive substance in its tissues.
Some animals feed on plants; other living things feed on the creatures that feed on plants. Via this food chain, the radioactive carbon that plants have absorbed from the air is transferred to other living things. In this way, every living thing on Earth absorbs an equal level of carbon-14 into its body.
When that plant or an animal dies, it is of course no longer able to feed and absorb any more carbon-14. Since carbon-14 is a radioactive substance, it has a half-life, and gradually begins losing electron. Thus the age of a once-living thing can be calculated by measuring the amount of carbon-14 left in its tissues.
The half-life of carbon-14 is around 5,570 years. In other words, the amount of carbon-14 in the dead tissue declines by half once every 5.570 years. For example, if there were 10 grams of carbon-14 in a living thing’s body 5.570 years ago, then there will now be only 5 grams. This test, like other radiometric tests, cannot be used to determine the age of specimens which are thought to be very old, since carbon-14 has only a short half-life. Carbon-14 dating is regarded as giving accurate results for specimens between 10,000 and 60,000 years old.
Carbon-14 testing is one of the dating tests most frequently employed. Evolutionists use this method in order to determine age when examining the fossil record. However, as with other radiometric tests, there are serious doubts concerning the reliability of carbon-14 dating. The most important of these is the high likelihood of gas exchange between the specimen to be dated and the outside environment. This exchange mostly comes about by means of waters containing carbonate or bicarbonate. If these natural waters—which contain carbon-14—come into contact with the specimen, then some of the carbon-14 atoms they contain will pass into the specimen. In that event, the specimen will test younger than it really is.
The exact opposite of this situation may also arise. Under certain conditions, the amount of carbon-14 in the specimen to be dated can be released into the external environment in the form of carbonate and/or bicarbonate. In that event, the specimen will appear to be older than it actually is.
Indeed, various concrete findings have revealed that carbon-14 dating is not all that reliable. Carbon-14 dating tests on specimens whose age is known for certain have often given false results. For instance, the skin of a newly dead seal was depicted as being 1.300 years old.70 A living shell was dated as 2.300 years old.71 A deer antler was variously dated as 5.340, 9.310 and 10.320 years old.72