Radiometric Dating – Is It Accurate?

Radiometric dating is a much misunderstood phenomenon. Evolutionists often misunderstand the method, assuming it gives a definite age for tested samples. Creationists also often misunderstand it, claiming that the process is inaccurate.

Radiometric Dating Is Not Inaccurate

Perhaps a good place to start this article would be to affirm that radiometric dating is not inaccurate. It is certainly incorrect, and it is certainly based on wrong assumptions, but it is not inaccurate.

What do I mean? How can something be accurate and yet wrong? To understand this point, we need to understand what exactly is being measured during a radiometric dating test. One thing that is not being directly measured is the actual age of the sample.

No “Age-Meter”

There is no “age-meter” that you can plug into a rock, giving an immediate read-out of the rock’s age. It needs to be remembered that observational science can only measure things in the here-and-now, in a manner which can be repeated. Historical science is concerned with trying to work out what may have happened in a one-off event in the past. Historical science is not capable of repetition, checking or peer‑review. The age of a rock sample falls under the heading of historical science, not observational science. So what do the observational scientists in the radiometric dating lab do?

Radioactive isotopes are unstable and will decay into more stable isotopes of other elements. One common radiometric dating method is the Uranium-Lead method. This involves uranium isotopes with an atomic mass of 238. This is the most common form of uranium. It decays by a 14-step process into lead-206, which is stable. Each step involves the elimination of either an alpha or a beta particle. Therefore the process is:

Uranium Decay Equation

Each individual atom has a chance of decaying by this process. If you were able to examine just one atom, you would not know whether or not it would decay. The chance of it decaying is not definite, by human standards, and is similar to the chance of rolling a particular number on a dice. Although we cannot determine what will happen to an individual atom, we can determine what will happen to a few million atoms. This is similar to our dice analogy. We cannot tell what number we will roll in any one shake, but if we rolled 6,000 dice, the chances are very high that 1,000 of them would have landed on a six. One dice is unpredictable. Many dice follow a statistically predictable pattern. In the same way, one U-238 atom is unpredictable, but a sample containing many millions of U-238 atoms will be very predictable.

What happens statistically is that half of the available atoms will have decayed in a given period, specific to each radioactive species, called the half-life. For example, if element Aa had a half-life of 1 day and we had 1,000 lbs. of it on Monday, then we would have 500 lbs. on Tuesday, 250 lbs. (half of 500) on Wednesday and 125 lbs. on Thursday.

Determining Half-Life

By observing how fast U-238 decays into lead-206, we can calculate the half-life of U-238. This is a theoretical calculation, and we can therefore determine that the half-life of U-238 is 4.5 billion years. Remember that the half-life is a statistical measure. Granting that U-238 has a half-life of 4.5 billion years in no way negates the idea that the Earth is only 6,000 years old.

A very common rock that contains U-238 is granite. If we look at some of the very small zircon crystals in granite, we can accurately measure how much U-238 and Pb-206 the crystal contains. In order to calculate the age of the rock, we need three other pieces of information:

1. We need to know how fast the U-238 turns into Pb-206. The half-life gives us this value, provided the half-life has never altered during the lifetime of the zircon crystal.
2. We need to know how much Pb-206 there was in the original rock. This is clearly impossible. It is usually assumed, without justification, that the original quantity of Pb-206 in the rock was zero.
3. We need to be sure that no lead compounds have been added to or taken away from the rock. Given that lead compounds are fairly soluble in water, this is something that we cannot be very sure of.

Using the above assumptions, it is calculated that the zircon crystals have an age of about 1.5 billion years.

Based Upon Assumptions

The radioactive decay process above can be seen to produce 8 alpha-particles for each one atom of U-238. Each α-particle could gain new electrons and become an atom of helium. The rate of diffusion of helium from a zircon crustal can be measured. It turns out that this rate of diffusion of helium is compatible with the crystals being about 5,000 years old, not 1.5 billion years old. Although assumptions 2 and 3 are not provable, they actually seem very likely in this particular example. Therefore, it seems that the first assumption must be wrong¹. Remember that we have already said that these experimenters are highly skilled. It is therefore unlikely that the laboratory technicians have made a mistake in their measurements of U-238 or Pb-206. The only possible conclusion, therefore, is that the half-life of U-238 has not been constant throughout the lifetime of the granite and its zircon crystals.

Other radiometric dating methods are based on similar assumptions. If the assumptions cannot be trusted, then the calculations based on them are unsound. It is for this reason that creationists question radiometric dating methods and do not accept their results.

Wrong Assumptions In C-14 Dating Methods

• Creation Today

Atmospheric C-14 is in equilibrium

This assumption is wrong. It has been estimated that the C-14 in the earth’s atmosphere would reach equilibrium (the formation rate would be equal to the decay rate) in about 30,000 years. The amount of C-14 in the atmosphere is still increasing. This research indicates a young earth (probably less than 10,000 years).

The same research also modifies all dates obtained by C-14 decay. As the earth’s magnetic field decays, more cosmic radiation penetrates our atmosphere. On a Geiger counter, 16 clicks per minute per gram (16DPM/Gc) is typical in living objects today. Plants and animals that lived on the earth four thousand years ago would have had much less C-14 in their body to start with. The low amount of C-14 would make them appear to be thousands of years older than they really are. Several factors can affect the rate of C-14 formation. The 11-year solar sunspot cycle is one such factor.

Living penguins have been carbon dated as being 8,000 years old!

Decay rate remains constant

Many times this assumption has been shown to be uncertain. Because the rate of decay may not be constant, dates obtained by C-14 may be accepted, but only with caution.

Initial amounts of C-14 can be known

Many times this assumption has been demonstrated to be wrong. Different parts of the same sample often yield different ratios. Various living samples give very different ratios. Some items will not be tested with carbon dating even though they contain carbon (see number 5 below). Would a mollusk have the same amount of C-14 per gram of carbon as a tree? Probably not. Living penguins have been carbon dated at 8,000 years old! The oldest sample of independently known age is Hemaka, the Egyptian mummy from 2700–3100 BC. (Secular writers of antiquity tend to exaggerate ages, so even these dates are suspect.)

The sample being tested has not been contaminated for thousands of years.

This assumption is very difficult (if not impossible) to prove. Parent or daughter products may have leached in or out of the sample. Many lab tests have confirmed that this can happen.

The geologic column can be used as a base to calibrate the C-14 dates

This assumption is not wise. The ages applied to the geologic column (invented in the 1800s to discredit the Bible) do not exist anywhere in the world except in textbooks. Polystrata fossils, missing layers, layers out of order, misplaced fossils, and layers in reverse order all invalidate the geologic column.

Does carbon dating prove the earth is millions of years old?

Whenever the worldview of evolution is questioned, the topic of carbon dating always comes up. Here is how carbon dating works and the assumptions it is based upon.

How Carbon Dating Works

Radiation from the sun strikes the atmosphere of the earth all day long. This energy converts about 21 pounds of nitrogen into radioactive carbon 14. This radioactive carbon 14 slowly decays back into normal, stable nitrogen. Extensive laboratory testing has shown that about half of the C-14 molecules will decay in 5,730 years. This is called the half-life. After another 5,730 years half of the remaining C-14 will decay leaving only 1⁄4 of the original C-14. It goes from 1⁄2 to 1⁄4 to 1⁄8, etc. In theory it would never totally disappear, but after about 5 half-lives the difference is not measurable with any degree of accuracy. This is why most people say carbon dating is only good for objects less than 40,000 years old. Nothing on earth carbon dates in the millions of years, because the scope of carbon dating only extends a few thousand years. Willard Libby invented the carbon dating technique in the early 1950s. The amount of carbon 14 in the atmosphere today is about .0000765%. It is assumed there would be the same amount found in living plants or animals since the plants breath CO2 and animals eat the plants.

Since sunlight causes the formation of C-14 in the atmosphere, and normal radioactive decay takes it out, there must be a point where the formation rate and the decay rate equalizes. This is called the point of equilibrium. To illustrate: If you were trying to fill a barrel with water but there were holes drilled up the side of the barrel, as you filled the barrel it would begin leaking out the holes. At some point you would be putting it in and it would be leaking out at the same rate. You will not be able to fill the barrel past this point of equilibrium. In the same way the C-14 is being formed and decaying simultaneously. A freshly created earth would require about 30,000 years for the amount of C-14 in the atmosphere to reach this point of equilibrium because it would leak out as it is being filled. Tests indicate that the earth has still not reached equilibrium. There is more C-14 in the atmosphere now than there was 40 years ago. This would prove the earth is not yet 30,000 years old! This also means that plants and animals that lived in the past had less C-14 in them than do plants and animals today. Just this one fact totally upsets data obtained by C-14 dating.

The carbon in the atmosphere normally combines with oxygen to make carbon dioxide (CO2). Plants breathe CO2 and make it part of their tissue. Animals eat the plants and make it part of their tissues. A very small percentage of the carbon plants take in is radioactive C-14. When a plant or animal dies, it stops taking in air and food so it should not be able to get any new C-14. The C-14 in the plant or animal will begin to decay back to normal nitrogen. The older an object is, the less carbon 14 it contains. One gram of carbon from living plant material causes a Geiger counter to click 16 times per minute as the C-14 decays. A sample that causes 8 clicks per minute would be 5,730 years old (the sample has gone through one half-life) and so on.

The Assumptions of Carbon Dating

Although this technique looks good at first, carbon-14 dating rests on at least two simple assumptions. These are, obviously, the assumption that the amount of carbon 14 in the atmosphere has always been constant and that its rate of decay has always been constant. Neither of these assumptions is provable or reasonable. An illustration may help: Imagine you found a candle burning in a room, and you wanted to determine how long it was burning before you found it. You could measure the present height of the candle (say, 7 inches) and the rate of burn (say, an inch per hour). In order to find the length of time since the candle was lit, we would be forced to make some assumptions. We would, obviously, have to assume that the candle has always burned at the same rate, and assume an initial height of the candle. The answer changes based on the assumptions. Similarly, scientists do not know that the carbon-14 decay rate has been constant. They do not know that the amount of carbon 14 in the atmosphere is constant. Present testing shows the amount of C-14 in the atmosphere has been increasing since it was first measured in the 1950s. This may be tied in to the declining strength of the magnetic field.

In addition to the above assumptions, dating methods are all subject to the geologic column date to verify their accuracy. If a date obtained by radiometric dating does not match the assumed age from the geologic column, the radiometric date will be rejected. The so-called geologic column was developed in the early 1800s over a century before there were any radio- metric dating methods. “Apart from very ‘modern’ examples, which are really archaeology, I can think of no cases of radioac- tive decay being used to date fossils.”¹ Laboratories will not carbon date dinosaur bones (even frozen ones which could easily be carbon dated) because dinosaurs are supposed to have lived 70 million years ago according to the fictitious geologic column. An object’s supposed place on the geologic column determines the method used to date it. There are about 7 or 8 radioactive elements that are used today to try to date objects. Each one has a different half-life and a different range of ages it is supposed to be used for. No dating method cited by evolutionists is unbiased.²

The Wild Dates of Carbon Dating

A few examples of wild dates by radiometric dating:

• Shells from living snails were carbon dated as being 27,000 years old.
• Living mollusk shells were dated up to 2,300 years old.
• A freshly killed seal was carbon dated as having died 1,300 years ago.
• “One part of the Vollosovitch mammoth carbon dated at 29,500 years and another part at 44,000.”
• “Structure, metamorphism, sedimentary reworking, and other complications have to be considered. Radiometric dating would not have been feasible if the geologic column had not been erected first.”
• Material from layers where dinosaurs are found carbon dated at 34,000 years old.

Shtal, you're trying way too hard.  Let's for argument's sake, suppose all of your links are true and you've debunked the current model of evolution.  Do you realize what that would mean?  You STILL have not one ounce of proof that "God did it.".  Show me ONE piece of evidence that creation is true.

"Laboratories will not carbon date dinosaur bones...because"
THEY ARE FOSSILS AND THERE IS NO F'ING CARBON IN THEM.

You tell em Hundmutter ..........................BTW Good Morning......we might not know much but we know that then again Shtal doesn't know much either but he knows how to copy and paste...................

Just curious, you folks that don't believe in the God of the Bible, or any God for that matter,  (which is fine, to each his own) do you also not believe in ghosts, evils spirits or a devil also mentioned in the Bible?  How many of you read horoscopes, or have been to fortune tellers, or get scared out of your wits by a horror movie.

GSDtravels wrote: Show me ONE piece of evidence that creation is true,

If the earth is less than 30,000 thousand years old or more accurate number about ~6,000 thousand years old then creation is true....But if you show me piece of evidence that shows earth is millions/billions of years old then creation will not be logical answer because Bible teaches that earth is young.


I hope you understand!


Shtal.