Skip to main content
The Age of the Earth
Apr 1, 2004

Methods of Measuring the Earth’s Age

All methods of estimating “time” use the same principle: measuring the velocity of natural processes that show continuity over time. One of the most advanced methods of chronometry today is to use the velocity of quartz crystal vibrations when exposed to an electric field. The wristwatches we wear in our daily life are well-known applications of this method. Another method of measuring time is to measure the rate of decay of radioactive elements.

However, having a process with which to measure is not sufficient. To measure the time that has passed correctly there are three requirements that need to be satisfied. First of all, it is essential that the process is stable and immutable, even during the period before we were able to observe it. Secondly, the beginning state should be known. For example, the length of a candle before being lighted or the amount of water in a cup before being boiled should be known. Thirdly, the process should not be influenced by any outer effects.

Today, all these three factors have been applied in studies of measuring time. But, when the question comes down to Geochronometry (Measurement of geologic time, as through isotopic radioactive decay), they are somehow more difficult to apply. Since the selected process starts before the beginning of history, we do not have methods to observe the process directly or to make sure that these three requirements were met then as today. And this is where the problem starts.

For instance, we can use the salinity of the oceans as a means of measuring the age of the Earth (This method was developed in 1898 by Irish geologist John Joly). This is a promising method, because it is assumed that the amount of salt in the water of the ocean was originally zero, and that salt was propelled by rainwater and rivers from the soil. The encouraging fact about this method is that the amount of salt brought to the oceans by rainwater and rivers is constant (approximately 540 million tons of salt annually). Today, the average density of salt in oceans is nearly 32 grams per liter. By using this ratio, we can calculate the total amount of salt in the oceans as being approximately 50 quadrillion tons. When we divide this number by the amount of salt propelled annually, we can find the age of the Earth in years.

Joly calculated this as being 100 million years using this method. However, considering the study in light of the three requirements mentioned above, the shortcomings of this method are obvious. Firstly, we cannot really be sure that the amount of salt propelled was static in the geological past. There is good reason to think that the climate and annual rainfall might have been significantly different in the past. Ice ages, great droughts, excessive rains, and the undeterminable effects of these factors may have all played a part. Secondly, it is impossible to be sure that the oceans were salt-free at the beginning. They may have contained some salt (recent research carried out in the Atlantic demonstrates the possibility that salt could have penetrated through to the oceans from the magma layer). Thirdly, some external influences may have affected this so-called stable process. There is a large and self-replicating circulation of salt in the atmosphere. New clues lead us to think that the amount of salt in oceans today is stable. As soon as the salt propelled by rivers accumulates, it evaporates at the same speed. While a huge amount of salt evaporates in biological processes, a greater amount penetrates to the depths of the seas.

The Uranium-Lead Method

All the methods that estimate the age of the Earth suffer from the same shortcomings to some degree. The radiometric age estimation method, which can estimate age up to 4.5 million years, consists of measuring radioactive elements that have a long half-life and that maintain their radioactivity over a long period. These elements are uranium and thorium, which decay into helium and lead, rubidium, which decays into strontium, and potassium, which decays into argon. However, as we will see, the Uranium-Lead method has been given great importance, in particular by evolutionists.

The basic principle involved is that radioactive uranium 238, uranium 235, and thorium 232 atoms eventually decay into miscellaneous lead atoms, without any trigger (in addition, uranium 238 decays into helium gas).

Interestingly, the decay rate of each element is definite. Uranium and thorium atoms periodically radiate alpha particles. However, it is unpredictable which atom will decay when. But in any substantial mass of the mineral there will be many billions of atom, and with very large numbers of events the “law of large numbers” operates to produce a statistically predictable result.

The significant part of this theory is that radiogenic lead 206, which is not radioactive and which is decayed from radioactive uranium 238, is found in rocks. However, it differs chemically from lead 204, which is neither radioactive nor radiogenic. To estimate the age of a rock, it is split and the amounts of radioactive uranium and radiogenic lead found are measured. Since the decay rate is known, it is possible to calculate the age of the rock.

The half-life of uranium 238 - one of the isotopes used - is calculated as being 4.5 million years. This means that half of any amount of uranium 238 will decay into lead 206 in 4.5 million years. For instance, if an investigation shows that half of a rock consists of uranium 238, and the other half consists of lead 206, which is the final product of uranium 238, the rock is then 4.5 million years old (although this number has not been calculated by a direct measurement, it is an average age for the crust of the Earth).

If radiogenic lead (lead 206 that has decayed from uranium 238, lead 207 that has decayed from uranium 235, and lead 208 that has decayed from thorium 232) are truly the products of radioactive decay then it is assumed that these rocks contained no radiogenic lead at the very start of the process of rock formation. This is a reliable starting point for calculations. Simi-larly, it is assumed that radiogenic lead cannot penetrate rocks in any other way, and conse-quently there is no process that can affect the decay process. However, when examined carefully, we can see that this is not really the case. A new process in which “natural” lead transforms into a form that cannot be distinguished from radiogenic lead was discovered by experimentation (Cook, 1966). This transformation occurs by natural lead taking hold of free neutrons. These neutrons are atoms that have the energy to transform natural lead into radiogenic lead. Then what is the source of the free neutrons?

The Origin of Lead 208

The source of lead 208 lies in a radioactive mine bed where natural fission (the division of the nucleus of uranium) has taken place. (A uranium bed were such natural fission occurs has been found in The Gabon.) In this uranium bed, while some uranium 238 atoms decay into lead 206, others divide by natural fission and produce neutrons. These neutrons simultaneously transform natural lead (lead 204) and radiogenic lead (lead 206) to lead 208 isotopes in a gradual process. This isotope cannot be distinguished experimentally from lead 208, a product of the alpha decay of thorium 232. Therefore, the lead 208 isotope emerges from two different sources. However, Darwinists state that all lead 208 isotopes detected are the product of thorium 232, which would mean that there is a large amount of radiogenic lead, and subsequently that the process continues for a long time. Significantly, this is a mechanism that would tip our measurements in favor of an “old” Earth.

In the neutron capture process, the isotopic values of lead would be systematically changed: lead 206 would be converted into lead 207, and lead 207 into lead 208 by taking on a single neutron. What is interesting is that lead 208 makes up more than half of the lead in the bed. According to Darwinists, this means that there was a large amount of naturally occurring thorium 232 in that bed, which later changed into lead 208. However, Melvin Cook, who carried out research in uranium beds in Zaire and Canada (the largest uranium beds in the world) states that, although the beds do not contain thorium 232, they do contain a large amount of lead 208. This can only mean that lead 208 results from lead 207 taking hold of a neutron. He also states that all radiogenic lead can be accounted for in this way.

Other people have tried to denigrate Cook, a man who believed in “creation”, and his studies. Among these is the geologist Brent Dalrymple from the U.S. Geological Survey. Neither Dalrymple, who argued that the level of free neutrons were too low to make any significant difference in the number of lead 208 as lead isotopes in the beds, nor could anyone else provide a satisfactory explanation to why, although there was no thorium 232 in the beds, lead 208 was found in huge amounts. Uranium decay not only degrades the most important criteria of a reliable geocronometry method, but it also degrades the criteria of the process, i.e that it is stable, immutable, and not intervened with. Uranium, which naturally emerges as an oxide rather than a metal, and which shows a very high capacity of dissolving in water because of this property, ekes out of its original bed with water. Its effect in age estimation is unpredictable, as while some parts of the bed are poor in uranium, other parts are rich.

The Helium Problem

Beside lead, one of the final products produced in the decay of uranium 238 is radiogenic helium, the atomic weight of which is 4. It is thought that a significant proportion of helium in the atmosphere is radiogenic helium that emerges in the decay process that has continued throughout history. If the uranium-lead age estimation method is reliable, then the amount of helium in the atmosphere must suggest an age in agreement to the age provided by radiogenic lead estimation. However, the ages acquired from the two methods are significantly different. If the Earth were 4.6 billion years old, then there would be roughly 100 trillion tons of radiogenic helium 4 in the atmosphere. Actually, there are only around 3.5 billion tons present – several thousand times less than there should be (0.035 % to be precise).

Writing in Nature on the “mystery” of the Earth’s missing radiogenic helium, Melvin Cook says: “...Hence more than 1,020 grams of helium should have passed into the atmosphere since the ‘beginning.’ Because the atmosphere contains only 3.5x1,015 grams of helium 4, it must also have passed out through the exosphere, and that the present rate of loss through the atmosphere balances the rate of exudation from the lithosphere.”

Cook says that uniformitarian geologists have attempted to explain this discrepancy by assuming that the other 99.96 percent has escaped from Earth’s gravitational field into space – but this process has not been observed. In 1984, Dalrymple argued a mechanism that can explain this difference and that provides a reply to Cook’s proposal: “Banks and Holzer have shown that the polar wind can account for an escape of 2 to 4 million ions/cm2 per second of helium 4, which is nearly identical to the estimated production flux of 2.51.5 million atoms/cm2 per second.”

There are two things that make Banks and Holzer’s findings unsuitable for the purposes to which Dalrymple tries to fit them. First of all, if the Earth really is 4.5 billion years old, then its atmosphere would have to lose helium at a rate somewhere around 1,016 atoms/cm2 per second, or some ten orders of magnitude faster than Dalrymple’s figure, to account for the missing helium.

Secondly, the numbers Dalrymple used were calculated 30 years ago. In that period, most scientists believed that the Earth moved in empty space (i.e., that nothing encapsulated the Earth but emptiness), and that hydrogen and helium atoms escaped to emptiness. New studies have shown that, rather than losing helium, the atmosphere gains a significant amount of helium. Since the Earth rotates around the Sun, it does not move in empty space, it moves in the atmosphere of the Sun, which is made up of mainly helium and hydrogen that have emerged from the nuclear processes that occur on the Sun. According to research, the Earth gains helium in this way as well.

In his book (1987) Gaia: A New Look at Life on Earth, space scientist James Lovelock writes: “The outermost layer of the air, so thin as to contain only a few hundred atoms per cubic centimeter, the exosphere, can be thought of as merging into the equally thin outer atmosphere of the Sun. It used to be assumed that the escape of hydrogen atoms from the exosphere gave the Earth its oxygen atmosphere. Not only do we now doubt that this process is on a sufficient scale to account for oxygen, but we rather suspect that the loss of hydrogen atoms is offset or even counterbalanced by the flux of hydrogen from the Sun.”

Lovelock mentions hydrogen, not helium. Helium is four times heavier than hydrogen and exists in abundance in the Sun’s atmosphere, since it is the main product of the nuclear fusion process on the Sun. If hydrogen were gained instead of being lost, it would be reasonable to expect this to occur for helium as well. Cook says: “If we take the amount of helium 4 measured in the atmosphere and then apply the radioactive age estimation technique, we will find that the age of the Earth is approximately 175,000 years. This invalidates our reliability criteria; the possible flow of helium from external sources interrupts this process.”

Cook is not alone in his thoughts. In articles published in influential journals, similar suspicions have been stated. Funkhouser and Naughton from the Hawaiian Geophysics Institute calculated the ages of volcanic rocks that had emerged from Mount Kilauea by using the potassium-argon method and calculated them to be nearly 3 million years old. However, it is know that these rocks were formed during a volcanic eruption in 1801. McDougall from the Australian National University calculated the age of lava in New Zealand to be up to 465,000 years old, even though it was known to be less than 1,000 years old (Milton 1997).

As a result, the reliability of radioactive age estimation is doubtful. What is being measured is the amount of products that have decayed, not the rate of decay. It is also difficult to discuss the origin of these products. Subsequently, all radioactive geocronometry methods can be said to be highly flawed and to lack reliability. The only reliable result that emerges from the incompatibility between uranium-lead age and uranium-helium age is the conclusion that radioactive age estimation is totally unreliable. The methods based on the decay of potassium into argon and rubidium into strontium suffer from the above mentioned shortcomings, in addition to others. However, some scientists try hard to advocate one single idea: evolution. The evolution lobby dampens the volume of courageous scientists, such as Milton and Cook, damages their prestige and frightens others by the overwhelming atmosphere they have created. All methods developed to estimate the age of the Earth are full of inconsistencies. Only one among them (based on the radioactive decay of elements, such as uranium) provided an age of millions of years for the Earth. While that single technique was supported enthusiastically by Darwinists, all others were ignored. This was because according to Darwinist theory, evolution required a long geological past in order to display its results in the long term. This propaganda program by the Darwinists was so successful that almost everyone, including scientists from different fields, have come to believe that radioactive age estimation is the only unquestionable and valid method for age estimation. Yet, as we have discussed above, all of these widely accepted beliefs lack sufficient support.


  • Milton, R., Shattering the Myths of Darwinism. Park Street Press. Vermont, 1997.
  • Lovelock, J. E., Gaia: A New Look at Life on Earth. Oxford University Press, 1997.