Shop Now Scientists use a technique called radiometric dating to estimate the ages of rocks, fossils, and the earth. Many people have been led to believe that radiometric dating methods have proved the earth to be billions of years old. With our focus on one particular form of radiometric dating—carbon dating—we will see that carbon dating strongly supports a young earth.
Note that, contrary to a popular misconception, carbon dating is not used to date rocks at millions of years old. Basics Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry. Recall that atoms are the basic building blocks of matter. Atoms are made up of much smaller particles called protons, neutrons, and electrons. Protons and neutrons make up the center nucleus of the atom, and electrons form shells around the nucleus.
The number of protons in the nucleus of an atom determines the element. For example, all carbon atoms have 6 protons, all atoms of nitrogen have 7 protons, and all oxygen atoms have 8 protons.
The number of neutrons in the nucleus can vary in any given type of atom. So, a carbon atom might have six neutrons, or seven, or possibly eight—but it would always have six protons. The illustration below shows the three isotopes of carbon. There are two main applications for radiometric dating. One is for potentially dating fossils once-living things using carbon dating, and the other is for dating rocks and the age of the earth using uranium, potassium and other radioactive atoms.
The atomic number corresponds to the number of protons in an atom. Atomic mass is a combination of the number of protons and neutrons in the nucleus. The electrons are so much lighter that they do not contribute significantly to the mass of an atom. Carbon Dating Carbon 14C , also referred to as radiocarbon, is claimed to be a reliable dating method for determining the age of fossils up to 50, to 60, years. If this claim is true, the biblical account of a young earth about 6, years is in question, since 14C dates of tens of thousands of years are common.
God knows just what He meant to say, and His understanding of science is infallible, whereas ours is fallible. So we should never think it necessary to modify His Word. Since the Bible is the inspired Word of God, we should examine the validity of the standard interpretation of 14C dating by asking several questions: Is the explanation of the data derived from empirical, observational science , or an interpretation of past events historical science?
Are there any assumptions involved in the dating method? Are the dates provided by 14C dating consistent with what we observe? Do all scientists accept the 14C dating method as reliable and accurate? All radiometric dating methods use scientific procedures in the present to interpret what has happened in the past.
The procedures used are not necessarily in question. The interpretation of past events is in question. The secular evolutionary worldview interprets the universe and world to be billions of years old. The Bible teaches a young universe and earth.
Which worldview does science support? Can carbon dating help solve the mystery of which worldview is more accurate? The use of carbon dating is often misunderstood. Carbon is mostly used to date once-living things organic material. It cannot be used directly to date rocks; however, it can potentially be used to put time constraints on some inorganic material such as diamonds diamonds could contain carbon Because of the rapid rate of decay of 14C, it can only give dates in the thousands-of-year range and not millions.
There are three different naturally occurring varieties isotopes of carbon: Carbon is used for dating because it is unstable radioactive , whereas 12C and 13C are stable. Radioactive means that 14C will decay emit radiation over time and become a different element. If 14C is constantly decaying, will the earth eventually run out of 14C? The answer is no. Carbon is constantly being added to the atmosphere. These cosmic rays collide with atoms in the atmosphere and can cause them to come apart.
Neutrons that come from these fragmented atoms collide with 14N atoms the atmosphere is made mostly of nitrogen and oxygen and convert them into 14C atoms the neutron is accepted and a proton is ejected from the nucleus. Once 14C is produced, it combines with oxygen in the atmosphere 12C behaves like 14C and also combines with oxygen to form carbon dioxide CO2.
Because CO2 gets incorporated into plants which means the food we eat contains 14C and 12C , all living things should have the same ratio of 14C and 12C in them as in the air we breathe. As long as an organism is alive it will continue to take in 14C; however, when it dies, it will stop. Since 14C is radioactive decays into 14N , the amount of 14C in a dead organism gets less and less over time. Therefore, part of the dating process involves measuring the amount of 14C that remains after some has been lost decayed.
In order to actually do the dating, other things need to be known. Two such things include the following questions: How fast does 14C decay? What was the starting amount of 14C in the creature when it died? The decay rate of radioactive elements is described in terms of half-life. The half-life of an atom is the amount of time it takes for half of the atoms in a sample to decay.
The half-life of 14C is 5, years. For example, a jar starting with all 14C atoms at time zero will contain half 14C atoms and half 14N atoms at the end of 5, years one half-life. At the end of 11, years two half-lives the jar will contain one-quarter 14C atoms and three-quarter 14N atoms.
Since the half-life of 14C is known how fast it decays , the only part left to determine is the starting amount of 14C in a fossil. If scientists know the original amount of 14C in a creature when it died, they can measure the current amount and then calculate how many half-lives have passed. Since no one was there to measure the amount of 14C when a creature died, scientists need to find a method to determine how much 14C has decayed.
To do this, scientists use the main isotope of carbon, called carbon 12C. Because 12C is a stable isotope of carbon, it will remain constant; however, the amount of 14C will decrease after a creature dies.
All living things take in carbon 14C and 12C from eating and breathing. Therefore, the ratio of 14C to 12C in living creatures will be the same as in the atmosphere. This ratio turns out to be about one 14C atom for every 1 trillion 12C atoms. Scientists can use this ratio to help determine the starting amount of 14C. When an organism dies, this ratio 1 to 1 trillion will begin to change. The amount of 12C will remain constant, but the amount of 14C will become less and less.
The smaller the ratio, the longer the organism has been dead. The following illustration demonstrates how the age is estimated using this ratio.