How old is the earth

How old is Earth?

By Nola Taylor Tillman published 20 August 21

Here’s how scientists figure out how old Earth is.

Planet Earth doesn’t have a birth certificate to record its formation, which means scientists spent hundreds of years struggling to determine the age of the planet. So, just how old is Earth?

By dating the rocks in Earth’s ever-changing crust, as well as the rocks in Earth’s neighbors, such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.

How old are Earth’s rocks?

Scientists have made several attempts to date the planet over the past 400 years. They’ve attempted to predict the age based on changing sea levels, the time it took for Earth or the sun to cool to present temperatures and the salinity of the ocean. As the dating technology progressed, these methods proved unreliable; for instance, the rise and fall of the ocean was shown to be an ever-changing process rather than a gradually declining one.

And in another effort to calculate the age of the planet, scientists turned to the rocks that cover its surface. However, because plate tectonics constantly changes and revamps the crust, the first rocks have long since been recycled, melted down and reformed into new outcrops.

Scientists also must battle an issue called the Great Unconformity, which is where sedimentary layers of rock appear to be missing (at the Grand Canyon, for example, there’s 1.2 billion years of rock that can’t be found, according to the University of Arizona (opens in new tab) ). There are multiple explanations for this uncomformity; in early 2019, one study suggested that a global ice age caused glaciers to grind into the rock, causing it to disintegrate. Plate tectonics then threw the crushed rock back into the interior of the Earth, removing the old evidence and turning it into new rock.

In the early 20th century, scientists refined the process of radiometric dating. Earlier research had shown that isotopes of some radioactive elements decay into other elements at a predictable rate. By examining the existing elements, scientists can calculate the initial quantity of a radioactive element, and thus how long it took for the elements to decay, allowing them to determine the age of the rock.

The oldest rocks on Earth found to date are the Acasta Gneiss in northwestern Canada near the Great Slave Lake, which are 4.03 billion years old. But rocks older than 3.5 billion years can be found on all continents. Greenland boasts the Isua supracrustal rocks (3.7 to 3.8 billion years old), while rocks in Swaziland are 3.4 billion to 3.5 billion years. Samples in Western Australia run 3.4 billion to 3.6 billion years old.

Research groups in Australia found the oldest mineral grains on Earth. These tiny zirconium silicate crystals have ages that reach 4.3 billion years, making them the oldest terrestrial materials found on Earth so far. Their source rocks have not yet been found. Meanwhile, scientists have also found 7-billion-year-old stardust on Earth.

The rocks and zircons set a lower limit on the age of Earth of 4.3 billion years, because the planet itself must be older than anything that lies on its surface.

When life arose is still under debate, especially because some early fossils can appear as natural rock forms. Some of the earliest forms of life have been found in Western Australia, as announced in a 2018 study; the researchers found tiny filaments in 3.4-billion-year-old rocks that could be fossils. Other studies suggest that life originated even earlier. Hematite tubes in volcanic rock in Quebec could have included microbes between 3.77 and 4.29 billion years ago. Researchers looking at rocks in southwestern Greenland also saw cone-like structures that could have surrounded microbial colonies some 3.7 billion years ago.

How old is the solar system?

In an effort to further refine the age of Earth, scientists began to look outward. The material that formed the solar system was a cloud of dust and gas that surrounded the young sun. Gravitational interactions coalesced this material into the planets and moons at about the same time. By studying other bodies in the solar system, scientists are able to find out more about the early history of the planet.

The nearest body to Earth, the moon, doesn’t experience the resurfacing processes that occur across Earth’s landscape. As such, rocks from early lunar history still sit on the surface of the moon. Samples returned from the Apollo and Luna missions revealed ages between 4.4 billion and 4.5 billion years, helping to constrain the age of Earth. How the moon formed is a matter of debate; while the dominant theory suggests a Mars-size object crashed into Earth and the fragments eventually coalesced into the moon, other theories suggest that the moon formed before Earth.

In addition to the large bodies of the solar system, scientists have studied smaller rocky visitors that have fallen to Earth. Meteorites spring from a variety of sources. Some are cast off from other planets after violent collisions, while others are leftover chunks from the early solar system that never grew large enough to form a cohesive body.

Although no rocks have been deliberately returned from Mars, samples exist in the form of meteorites that fell to Earth long ago, allowing scientists to make approximations about the age of rocks on the Red Planet. Some of these samples have been dated to 4.5 billion years old, supporting other calculations of the date of early planetary formation.

More than 70 meteorites that have fallen to Earth have had their ages calculated by radiometric dating. The oldest of these are between 4.4 billion and 4.5 billion years old.

Fifty thousand years ago, a rock hurled down from space to form Meteor Crater in Arizona. Shards of that asteroid have been collected from the crater rim and named for the nearby Canyon Diablo. The Canyon Diablo meteorite is important because it represents a class of meteorites with components that allow for more precise dating.

In 1953, Clair Cameron Patterson, a renowned geochemist at the California Institute of Technology, measured ratios of lead isotopes in samples of the meteorite that put tight constraints on Earth’s age. Samples of the meteorite show a spread from 4.53 billion to 4.58 billion years. Scientists interpret this range as the time it took for the solar system to evolve, a gradual event that took place over approximately 50 million years.

By using not only the rocks on Earth but also information gathered about the system that surrounds it, scientists have been able to place Earth’s age at approximately 4.54 billion years. For comparison, the Milky Way galaxy that contains the solar system is approximately 13.2 billion years old, while the universe itself has been dated to 13.8 billion years.

How Old Is The Earth?

This article comes from the Universe Today archive, but was updated with this spiffy video.

How old is the Earth? Scientists think that the Earth is 4.54 billion years old. Coincidentally, this is the same age as the rest of the planets in the Solar System, as well as the Sun. Of course, it’s not a coincidence; the Sun and the planets all formed together from a diffuse cloud of hydrogen billions of years ago.

In the early Solar System, all of the planets formed in the solar nebula; the remnants left over from the formation of the Sun. Small particles of dust collected together into larger and larger objects – pebbles, rocks, boulders, etc – until there were many planetoids in the Solar System. These planetoids collided together and eventually enough came together to become Earth-sized.

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At some point in the early history of Earth, a planetoid the size of Mars crashed into our planet. The resulting collision sent debris into orbit that eventually became the Moon.

How do scientists know Earth is 4.54 billion years old? It’s actually difficult to tell from the surface of the planet alone, since plate tectonics constantly reshape its surface. Older parts of the surface slide under newer plates to be recycled in the Earth’s core. The oldest rocks ever found on Earth are 4.0 – 4.2 billion years old.

Scientists assume that all the material in the Solar System formed at the same time. Various chemicals, and specifically radioactive isotopes were formed together. Since they decay in a very known rate, these isotopes can be measured to determine how long the elements have existed. And by studying different meteorites from different locations in the Solar System, scientists know that the different planets all formed at the same time.

Failed Methods for Calculating the Age of the Earth
Our current, accurate method of measuring the age of the Earth comes at the end of a long series of estimates made through history. Clever scientists discovered features about the Earth and the Sun that change over time, and then calculated how old the planet Earth is from that. Unfortunately, they were all flawed for various reasons.

Radiometric Dating Provides an Accurate Method to Know the Age of the Earth
In 1896, the French chemist A. Henri Becquerel discovered radioactivity, the process where materials decay into other materials, releasing energy. Geologists realized that the interior of the Earth contained a large amount of radioactive material, and this would be throwing off their calculations for the age of the Earth. Although this discovery revealed flaws in the previous methods of calculating the age of the Earth, it provided a new method: radiometric dating.

Geologists discovered that radioactive materials decay into other elements at a very predictable rate. Some materials decay quickly, while others can take millions or even billions of years to fully decay. Ernest Rutherford and Frederick Soddy, working at McGill University, determined that half of any isotope of a radioactive element decays into another isotope at a set rate. For example, if you have a set amount of Thorium-232, half of it will decay over a billion years, and then half of that amount will decay in another billion years. This is the source of the term “half life”.

By measuring the half lives of radioactive isotopes, geologists were able to build a measurement ladder that let them accurately calculate the age of geologic formations, including the Earth. They used the decay of uranium into various isotopes of lead. By measuring the amount of three different isotopes of lead (Pb-206, Pb-207, and Pb-208 or Pb-204), geologists can calculate how much Uranium was originally in a sample of material.

If the Solar System formed from a common pool of matter, with uniformly distributed Pb isotopes, then all objects from that pool of matter should show similar amounts of the isotopes. Also, over time, the amounts of Pb-206 and Pb-207 will change because as these isotopes are end-products of uranium decay. This makes the amount of lead and uranium change. The higher the uranium-to-lead ratio of a rock, the more the Pb-206/Pb-204 and Pb-207/Pb-204 values will change with time. Now, supposing that the source of the Solar system was also uniformly distributed with uranium isotopes, then you can draw a data line showing a lead-to-uranium plot and, from the slope of the line, the amount of time which has passed since the pool of matter became separated into individual objects can be computed.

Bertram Boltwood applied this method of dating to 26 different samples of rocks, and discovered that they had been formed between 92 and 570 million years old, and further refinements to the technique gave ages between 250 million to 1.3 billion years.

Geologists set about exploring the Earth, seeking the oldest rock formations on the planet. The oldest surface rock is found in Canada, Australia and Africa, with ages ranging from 2.5 to 3.8 billion years. The very oldest rock was discovered in Canada in 1999, and estimated to be just over 4 billion years old.

This set a minimum age for the Earth, but thanks to geologic processes like weathering and plate tectonics, it could still be older.

Meteorites as the Final Answer to the Age of the Earth
The problem with measuring the age of rocks on Earth is that the planet is under constant geological change. Plate tectonics constantly recycle portions of the Earth, blending it up and forever hiding the oldest regions of the planet. But assuming that everything in the Solar System formed at the same time, meteorites in space have been unaffected by weathering and plate tectonics here on Earth.

Geologists used these pristine objects, such as the Canyon Diablo meteorite (the fragments of the asteroid that impacted at Barringer Crater) as a way to get at the true age of the Solar System, and therefore the Earth. By using the radiometric dating system on these meteorites, geologists have been able to determine that the Earth is 4.54 billion years old within a margin of error of about 1%.

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Age of the Earth

The consensus view of scientists in relevant fields is that the age of the Earth and the solar system is roughly 4.54 billion (4.54 × 10 9 ± 1%) years, [1] [2] an age primarily derived by radiometric dating. Because of the molten state of the early Earth, erosion, and subduction of tectonic plates moving surface material into the Earth’s mantle, radiometric dating of materials originating on Earth provides a range of lower limits for the age of the Earth of approximately 3.8 to 4.2 billion years.

The best estimates of the age of the Earth are calculated from the ratios of lead and uranium in meteorites found on Earth. These estimates are verified by helioseismic dating.

Young Earth creationists falsely claim that radiometric dating systems produce inconsistent ages, and then use their own error to infer that Goddidit.

Contents

Early scientific attempts at determining the age of the Earth [ edit ]

Sir Isaac Newton speculated that because «comets occasionally hit the Sun», perhaps the Earth formed from the scattered debris and as such began in a molten state and has been cooling ever since. Spurred by this suggestion, Georges Louis Leclerc (Comte de Buffon) conducted a series of experiments in which he measured how long it took for iron balls glowing red hot to cool to approximately room temperature. He then used a rough-and-ready technique to extrapolate the data, estimating that the Earth must be about (at least) 75,000 years old. (Newton pointed out that it must be older than 50,000 years.) A while later, Jean-Baptiste Fourier refined Buffon’s investigation. Drawing from empirical measurements and observations, he formulated his own analytical theory of heat diffusion. Once again, he treated the young Earth as a molten sphere, but also took into account the insulating crust. In light of volcanic eruptions, this is natural after all. His formula yielded an age of (at least) 100 million years. [3]

In the second half of the 19 th century, William Thomson (Lord Kelvin) brought newly discovered laws of thermodynamics to bear. Hermann von Helmholtz hypothesized that the energy of the Sun comes from gradual gravitational collapse. Kelvin calculated that the Sun must be between 50 to 500 million years old and, reassuringly, obtained similar figures for the Earth. Such a time scale was consistent with discoveries in geology and evolutionary biology of the time. (For whatever reason, perhaps religious, Kelvin later reduced his estimated to 24 million years, which was widely criticized. But we shall not bother with that here.) [4]

While these early attempts at determining how old Earth is seem rather quaint and inaccurate compared to more modern ones, they play a historically important role in science since people were then beginning to try to answer questions initially thought to be beyond the scope of science. Nuclear physics, which no one knew about at the time, was the missing ingredient in their calculations. In addition, even these primitive calculations conflict with Christian doctrine, something most were too afraid to question directly at the time.

Formation of the Solar System [ edit ]

Use of meteorites to date the Earth relies on assumptions required by various hypotheses of the formation of the Earth and other planets from the accretion disk created by the Jeans collapse of the material that formed our Sun. On its own, analysis of any particular meteorite may depend on the assumption of uniform rates of decay of radioactive isotopes, which creationists attack as unsound based on the necessary consequence of their dogmatic view that the Bible must trump science, and the uniform distribution of lead isotopes in the solar system. Taken together, analysis of various meteorites correlates ages of the early Solar System, and therefore the Earth, to a high degree of statistical significance.

A common creationist criticism of radiometric dating is that it provides inaccurate results. The claim is frequently due to attempts to analyze contaminated specimens or the use of methods inappropriate to the analysis of specific materials. The claim may also be due to a misunderstanding and inaccurate interpretation of scientific literature on the subject. [5] When used properly, radiometric dating provides results that are known to be accurate from their close correspondence with other methods of dating the Earth and solar system.

Formation of the Earth [ edit ]

Pre-scientific views [ edit ]

Cultures that existed prior to modern scientific scholarship generally did not imagine ages much beyond the longest time they could imagine – generally, thousands or perhaps tens of thousands of years. As they lacked any idea of modern scientific principles, religions were free to imagine whatever timescales seemed appropriate to their belief systems.

Early Christian and modern Young Earth Creationist views [ edit ]

There has always been a strand of Christianity that held idea that the Earth is only thousands of years old.

The two Genesis creation stories and the supposedly detailed listing of generations (also known as the «begats») reinforce the idea that the Earth must have been created within the last 10,000 years or so. Similarly, Talmudic commentaries over the last 2000 years place Creation at roughly 7,000 years, give or take many thousands of years.

In the 17 th century era of a new «rational» approach to the world, Christians, both theologians and scientists, attempted to define the Day of Creation more precisely. Isaac Newton, using the Bible as a template, worked out the year of creation of the Earth to be 4000 BCE, Johannes Kepler, 3992 BCE, and Bede at 3952 BCE.

The most famous date for the Day of Creation is the one proposed by James Ussher who determined that he could figure out the date of creation by compiling a chronology of all the events in the Bible, together with Persian and Chaldean histories for the inter-testamental period. Working back from a presumed date of Jesus’ birth of 0 BCE/CE Ussher arrived at a date of Creation of exactly Sunday, October 23, 4000 BCE. Learning that there was a miscalculation in the Gregorian calendar, and that Christ’s birth is roughly 3 years off, he amended his date to Sunday, October 23, 4004 BCE.

It is not at all surprising that all these dates spin near or around the 4000 BCE mark, as they are based on a popular Christian idea around the 17 th century that the Earth only had a 6000 year life span. [note 4]

Though most of modern Christianity has now set aside the clearly unscientific notion of «a few thousand years,» there persists a group of Christians called «Young Earth Creationists» who set the date of Creation as some time within the last 10,000 years. They originally followed Ussher’s dates; however, indisputable archaeological evidence of civilizations older than 6,000 years, generally pushes «YEC» types to say «up to 10,000 years.»

Islam [ edit ]

Islam, as per the Quran, says that the Earth was created in 6 days by Allah. [6] However, the word yaom which is literally translated as «days» has different spans of time, as in time is not of a fixed length but that it stretches and compresses as Allah wills. [7] This is evident when in one verse a «day» is equated to «fifty thousand years» [8] while in another verse a «day» is «one thousand years». However, the verse in which a «day» is equivalent to «fifty thousand years» has been shown to refer to Yawm-Al Qiyamah, or the Day of Judgement. [9] This directly corresponds with the use of the Hebrew word «yom» in the Judeo-Christian Tanakh, where «yom» is said to be on par with a thousand years. [10] Many people wrongly assume that Islam’s teaching of creation is entirely unlike that of the Bible’s. In truth, as a result of the Quran’s basis being the Bible, the two are thoroughly comparable. As such, many Muslims believe the Earth to be 6,000 years old. Other Muslims, however, take the view that Islam does not specify how long it has been since the creation of the Earth, as a result of the ambiguity of the word «yaom». [11]

Zoroastrian [ edit ]

The Zoroastrian religion is one of the few religions that provides a specific age in which the Universe and the Earth were made. The life of the Universe is 4 units of 3,000 years each, for a total of 12,000 years. The universe as we know it («all of Creation» is the term, so we will assume the Earth is part of Creation) was made after 3000 years of perfect balance. Thus making the age of the Earth somewhere between 6000-9000 years, depending on when it fell in the Age of Creation. [12]

Hinduism [ edit ]

On the other hand, according to Hinduism the Earth is much older. Hinduism states that the Earth came into being with the god Brahma, and after doing some calculations with units of time found in Hinduism we come up with an age of 155.5 trillion years. [13]

Dick Teresi in his book, Lost Discoveries: The Ancient Roots of Modern Science, reviews the Vedas and writes that «Twenty-four centuries before Isaac Newton, the Hindu Rig-Veda asserted that gravitation held the universe together, though the Hindu hypothesis was far less rigorous than Newton’s. The Sanskrit-speaking Aryans subscribed to the idea of a spherical earth in an era when the Greeks believed in a flat one. The Indians of the 5 th century CE calculated the age of the Earth as 4.3 billion years; scientists in 19 th century England were convinced it was 100 million years.» However, unlike the English scientists who based their estimates of Earth’s age on observations and their (limited) knowledge of the ability of energy sources to last for billions of years, the Hindu ideas were based on religious cosmology. Likewise, the Greeks changed their cosmology as regards the shape of the Earth due to observations made by Eratosthenes.

Science researchers, such as Carl Sagan [14] and Fritjof Capra [15] have stated similarities between the latest scientific information of the age of the Universe, and the Hindu concept of a «day and night of Brahma», which is much like the current known age of the Universe than other creation views. Sagan describes as:-

How Old Is Earth and How Did Scientists Figure It Out?

By: Patrick J. Kiger | Updated: Feb 4, 2021

How Old is the Earth?

If you look up the age of Earth on science websites and in publications, you’ll generally find an estimate of 4.54 billion years, plus or minus 50 million years. What you may be surprised to discover is the accepted estimate dates back to the 1950s and has remained pretty much the same since then, even though scientific knowledge has progressed so dramatically since then in other areas. So what’s up with that?

Historical Theories of the Earth’s Age

Efforts to figure out the age of Earth go back many centuries. The classical Greek philosopher Aristotle, who thought time had no beginning or end, also believed that Earth was infinitely old. Meanwhile religious scholars in ancient India, who envisioned a universe that perpetually exploded, expanded and collapsed only to begin anew, calculated that Earth had existed for 1.97 billion years.

During the medieval era, various Christian theologians scrutinized the Bible for clues, and came up with estimates of between 5,471 and 7,519 years, according to G. Brent Dalrymple’s book «The Age of the Earth.» From the 1700s and 1800s, an assortment of scientists came up with various figures based on clues ranging from Earth’s rate of cooling and the accumulation of sediment, to the chemical evolution of the oceans.

Radiometric Dating

Just before the beginning of the 20th century, scientists figured out that they could calculate the age of a rock by measuring radioactive decay, a method called radiometric dating.

Clair Patterson’s Discovery

In the early 1950s, a California Institute of Technology geochemist named Clair C. Patterson, who had worked on the Manhattan Project to develop the atomic bomb during World War II, measured the isotopic composition of lead from the Canyon Diablo meteorite and several other pieces of space rock, which were believed to data back to the disc of material from which Earth also formed. In 1953, Patterson came up with an estimate of 4.5 billion years. Since then, research on meteorites and lunar rocks has refined that number only slightly.

Although Patterson’s breakthrough made him famous in the world of science, he didn’t see it as a big deal. At the time, «No one cared about it,» he recalled in an oral history interview conducted shortly before his death in 1995. «Even today, people don’t care how old the earth is. In fact, less today than 40 years ago, when I measured it.»

Patterson had an even bigger impact by publishing a 1965 article on the extent of toxic lead pollution on Earth, which helped to start a movement to get rid of dangers such as lead paint and leaded gasoline, according to this 2015 article from the CalTech website.

How Old Is the Earth?

How old is the earth? The question of the age of the earth has produced heated discussions on internet debate boards, TV, radio, in classrooms, and in many churches, Christian colleges, and seminaries. The primary sides are

The difference is immense! Let’s give a little history of where these two basic calculations came from and which worldview is more reasonable when answering the question, «how old is the earth?»

Where Did a Young-earth Worldview Come From?

Simply put, it came from the Bible. Of course, the Bible doesn’t say explicitly anywhere, “The earth is 6,000 years old.” Good thing it doesn’t; otherwise it would be out of date the following year. But we wouldn’t expect an all-knowing God to make that kind of a mistake.

God gave us something better. In essence, He gave us a “birth certificate.” For example, using a personal birth certificate, a person can calculate how old he is at any point. It is similar with the earth. Genesis 1 says that the earth was created on the first day of creation ( Genesis 1:1–5 ). From there, we can begin to calculate the age of the earth.

Let’s do a rough calculation to show how this works. The age of the earth can be estimated by taking the first five days of creation (from earth’s creation to Adam), then following the genealogies from Adam to Abraham in Genesis 5 and 11, then adding in the time from Abraham to today.

Adam was created on day 6, so there were five days before him. If we add up the dates from Adam to Abraham, we get about 2,000 years, using the Masoretic Hebrew text of Genesis 5 and 11.3 Whether Christian or secular, most scholars would agree that Abraham lived about 2,000 B.C. (4,000 years ago).

So a simple calculation is:

At this point, the first five days are negligible. Quite a few people have done this calculation using the Masoretic text (which is what most English translations are based on) and with careful attention to the biblical details, they have arrived at the same time frame of about 6,000 years, or about 4000 B.C. Two of the most popular, and perhaps best, are a recent work by Dr. Floyd Jones4 and a much earlier book by Archbishop James Ussher5 (1581–1656). See table 1.

Table 1. Jones and Ussher

Table 2. Chronologists’ Calculations According to Dr. Jones

As you will likely note from table 2, the dates are not all 4004 B.C. There are several reasons chronologists have different dates,7 but two primary reasons:

The first four in table 2 (bolded) are calculated from the Septuagint, which gives ages for the patriarchs’ firstborn much higher than the Masoretic text or the Samarian Pentateuch (a version of the Old Testament from the Jews in Samaria just before Christ). Because of this, the Septuagint adds in extra time. Though the Samarian and Masoretic texts are much closer, they still have a few differences. See table 3.8

Using data from table 2 (excluding the Septuagint calculations and including Jones and Ussher), the average date of the creation of the earth is 4045 B.C. This still yields an average of about 6,000 years for the age of the earth.

Table 3. Septuagint, Masoretic, and Samarian Early Patriarchal Ages at the Birth of the Following Son

Extra-biblical Calculations for the Age of the Earth

Cultures throughout the world have kept track of history as well. From a biblical perspective, we would expect the dates given for creation of the earth to align more closely to the biblical date than billions of years.

This is expected since everyone was descended from Noah and scattered from the Tower of Babel. Another expectation is that there should be some discrepancies about the age of the earth among people as they scattered throughout the world, taking their uninspired records or oral history to different parts of the globe.

Under the entry “creation,” Young’s Analytical Concordance of the Bible9 lists William Hales’s accumulation of dates of creation from many cultures, and in most cases Hales says which authority gave the date. See table 4.

This meticulous work of many historians should not be ignored. Their dates of only thousands of years are good support for the biblical date of about 6,000 years, but not for billions of years.

Table 4. Selected Dates for the Age of the Earth by Various Cultures

* Luther, Kepler, Lipman, and the Jewish computation likely used biblical texts to determinethe date.

The Origin of the Old-earth Worldview

Prior to the 1700s, few believed in an old earth. The approximate 6,000-year age for the earth was challenged only rather recently, beginning in the late 18th century. These opponents of the biblical chronology essentially left God out of the picture. Three of the old-earth advocates included Comte de Buffon, who thought the earth was at least 75,000 years old. Pièrre LaPlace imagined an indefinite but very long history. And Jean Lamarck also proposed long ages.11

From these men and others came the consensus view that the geologic layers were laid down slowly over long periods of time based on the rates at which we see them accumulating today. Hutton said:

This viewpoint is called naturalistic uniformitarianism, and it excludes any major catastrophes such as Noah’s flood. Though some, such as Cuvier and Smith, believed in multiple catastrophes separated by long periods of time, the uniformitarian concept became the ruling dogma in geology.

Thinking biblically, we can see that the global flood in Genesis 6–8 would wipe away the concept of millions of years, for this Flood would explain massive amounts of fossil layers. Most Christians fail to realize that a global flood could rip up many of the previous rock layers and redeposit them elsewhere, destroying the previous fragile contents. This would destroy any evidence of alleged millions of years anyway. So the rock layers can theoretically represent the evidence of either millions of years or a global flood, but not both. Sadly, by about 1840, even most of the Church had accepted the dogmatic claims of the secular geologists and rejected the global flood and the biblical age of the earth.

After Lyell, in 1899, Lord Kelvin (William Thomson) calculated the age of the earth, based on the cooling rate of a molten sphere, at a maximum of about 20–40 million years (this was revised from his earlier calculation of 100 million years in 1862).13 With the development of radiometric dating in the early 20th century, the age of the earth expanded radically. In 1913, Arthur Holmes’s book, The Age of the Earth, gave an age of 1.6 billion years.14 Since then, the supposed age of the earth has expanded to its present estimate of about 4.5 billion years (and about 14 billion years for the universe).

Table 5. Summary of the Old-earth Proponents for Long Ages

But there is growing scientific evidence that radiometric dating methods are completely unreliable.15

Today, secular geologists will allow some catastrophic events into their thinking as an explanation for what they see in the rocks. But uniformitarian thinking is still widespread, and secular geologists will seemingly never entertain the idea of the global, catastrophic flood of Noah’s day.

The age of the earth debate ultimately comes down to this foundational question: Are we trusting man’s imperfect and changing ideas and assumptions about the past? Or are we trusting God ’s perfectly accurate eyewitness account of the past, including the creation of the world, Noah’s global flood, and the age of the earth?

Other Uniformitarian Methods for Dating the Age of the Earth

Radiometric dating was the culminating factor that led to the belief in billions of years for earth history. However, radiometric dating methods are not the only uniformitarian methods. Any radiometric dating model or other uniformitarian dating method can and does have problems, as referenced before. All uniformitarian dating methods require assumptions for extrapolating present-day processes back into the past. The assumptions related to radiometric dating can be seen in these questions:

If the assumptions are truly accurate, then uniformitarian dates should agree with radiometric dating across the board for the same event. However, radiometric dates often disagree with one another and with dates obtained from other uniformitarian dating methods for the age of the earth, such as the influx of salts into the ocean, the rate of decay of the earth’s magnetic field, and the growth rate of human population.16

The late Dr. Henry Morris compiled a list of 68 uniformitarian estimates for the age of the earth by Christian and secular sources.17 The current accepted age of the earth is about 4.54 billion years based on radiometric dating of a group of meteorites,18 so keep this in mind when viewing table 6.

Table 6. Uniformitarian Estimates Other than Radiometric Dating Estimates for Earth’s Age Compiled by Morris

* When a range of ages is given, the maximum age was used to be generous to the evolutionists. In one case, the date was uncertain so it was not used in this tally, so the total estimates used were 67. A few on the list had reference to Saturn, the sun, etc., but since biblically the earth is older than these, dates related to them were used.

As you can see from table 6, uniformitarian maximum ages for the earth obtained from other methods are nowhere near the 4.5 billion years estimated by radiometric dating; of the other methods, only two calculated dates were as much as 500 million years.

The results from some radiometric dating methods completely undermine those from the other radiometric methods. One such example is carbon-14 ( 14 C) dating. As long as an organism is alive, it takes in 14 C and 12 C from the atmosphere; however, when it dies, the carbon intake stops. Since 14 C is radioactive (decays into 14 N), the amount of 14 C in a dead organism gets less and less over time. Carbon-14 dates are determined from the measured ratio of radioactive carbon-14 to normal carbon-12 ( 14 C/ 12 C). Used on samples that were once alive, such as wood or bone, the measured 14 C/ 12 C ratio is compared with the ratio in living things today.

Now, 14 C has a derived half-life of 5,730 years, so the 14 C in organic material supposedly 100,000 years old should all essentially have decayed into nitrogen.19 Some things, such as wood trapped in lava flows, said to be millions of years old by other radiometric dating methods, still have 14 C in them.20 If the items were really millions of years old, then they shouldn’t have any traces of 14 C. Coal and diamonds, which are found in or sandwiched between rock layers allegedly millions of years old, have been shown to have 14 C ages of only tens of thousands of years.21 So which date, if any, is correct? The diamonds or coal can’t be millions of years old if they have any traces of 14 C still in them. This shows that these dating methods are completely unreliable and indicates that the presumed assumptions in the methods are erroneous.

Similar kinds of problems are seen in the case of potassium-argon dating, which has been considered one of the most reliable methods. Dr. Andrew Snelling, a geologist, points out several of these problems with potassium-argon, as seen in table 7.22

Table 7. Potassium-argon (K-Ar) Dates in Error

Conclusion: How Old Is The Earth?

When we start our thinking with God ’s Word, we see that the world is about 6,000 years old. When we rely on man’s fallible (and often demonstrably false) dating methods, we can get a confusing range of ages from a few thousand to billions of years, though the vast majority of methods do not give dates even close to billions.

Cultures around the world give an age of the earth that confirms what the Bible teaches. Radiometric dates, on the other hand, have been shown to be wildly in error.

The age of the earth ultimately comes down to a matter of trust—it’s a worldview issue. Will you trust what an all-knowing God says on the subject, or will you trust imperfect man’s assumptions and imaginations about the past that regularly are changing?

The New Answers Book 2

People complain about The New Answers Book. They say that it’s so good at giving short, substantive answers that they want more. Well, we listened! In The New Answers Book 2 you’ll find 31 more great answers to big questions for the Christian life. Many view the original New Answers Book as an essential tool for modern discipleship. Both of these books answer such questions as: Can natural processes explain the origin of life? Can creationists be real scientists? Where did Cain get his wife? Is evolution a religion? and more!