Can We Really Know the Earth is Billions of Years Old?

Can We Really Know the Earth is Billions of Years Old?

Kids love dinosaurs. They are big and scary and growl-y and dangerous. Proud parents beam as their precocious little paleontologists recite their wealth of dinosaur facts. The trouble starts when the little paleontologists learn that dinosaurs roamed the earth between 65 – 230 million years ago, a timeline that is hard to squeeze into an earth that is only 6,000 years old.

That’s when dinosaurs really become dangerous.

It wasn’t until the 20th century that a “young earth” (between 6,000 and 10,000 years old) became a widespread belief among evangelicals. A young earth created many problems: how do you reconcile apparently ancient events with a fairly short earth history? To make the math work in the case of the dinosaurs, dinosaurs and humans had to coexist. Maybe not exactly in the way they did in the town of Bedrock, but close.

fred and dinosaur

Apologetics Press (AP) is a prolific source of Young Earth Creationist (YEC) literature. An AP published science book for children, Dinosaurs Unleashed: The True story About Dinosaurs and Humans, includes illustrations of men fighting a vicious T-Rex, baby dinosaurs climbing a ramp to Noah’s Ark, and an idyllic scene of a young girl and her dinosaur pet. Not exactly Fred and Dino, but not too far from it.

               pet dino           dinos on ark           trex

When the age of the earth is a tenet of faith, conflict arises when scientific evidence doesn’t fit the faith-required parameters. The most common response is to somehow make the evidence fit the belief.

All scientific evidence points to an earth and a universe of immense age:

There are no scientific arguments of any consequence that point to the earth being just a few thousand years old. Not one isolated piece of nontrivial data, in any form, points in this direction (p. 54).

How Old is the Universe? How Do We Know?

The age of the universe is around twelve to fourteen billion years. Scientists arrived at this number because several unrelated lines of evidence converge on that number. Let’s look at two lines of evidence:

speed limit of light The speed of light: Light travels 186,000 miles per second. Our sun is 93 million miles away. When light leaves the sun, the light has to travel 93 million miles before we can see it. If you do the calculations, you will find that it takes eight minutes for light from the sun to reach the earth. When you see the sun, you are actually looking back in time. If the sun went dark, we would not know for eight minutes.

Our sun is relatively close to us, but other stars are unimaginably further away. They are so far away that it takes millions, even billions of years for the light from these distant stars to reach us. One way to estimate the age of the universe is to calculate how long it would take for the light we see from distant stars to reach us. The fact that we are seeing light from stars so far away tells us the universe  is billions of years old.

The Big Bang: Edwin Hubble (for whom the telescope was named) discovered in 1928 that virtually all of the galaxies in the universe are moving away from us. If the universe is expanding, it must have been smaller in the past. And since the universe is not infinitely large, there must have been a point in time when the expansion started from a single point – The Big Bang. (This is where you start to sing the opening lines of the sitcom Big Bang Theory to yourself: “…the whole universe was in a hot dense state then nearly fourteen billion years ago expansion started. Wait!”).

We know how fast the galaxies are traveling. The speed of the galaxies is measured in the same way a police officer measures the speed of your car – using radar to measure the Doppler effect. Knowing the rate of expansion and the average distances between galaxies, we can calculate how long the universe has been expanding from the starting point until now.

What if (as Young Earth Creationists suggest) God created light “in transit”?

Then what we see is not what actually is.

What about supernova – exploding stars – that are millions of light-years away? Those stars never actually existed according to YEC reasoning. Of course God could have created a universe with the appearance of age. God could have created everything ten minutes ago and placed a lifetime of memories in our brains.

Or, stars, galaxies, and supernova appear to be billions of years old because…they are.

How Old is the Earth? How D0 We Know?

As with the universe, the age of the earth has been determined using multiple, disparate lines of data that all converge at the same number. Here are some of the ways the age of the earth is determined:

Tree rings: We can determine the age of a tree by counting the rings on their trunks. The oldest living things on earth are six-thousand-year-old bristlecone pines in the Sierra Nevada. Dead trees lying nearby are almost twice as old.

Lake beds: Lake beds accumulate sediments according to the season: minerals in spring and pollens and plant materials in fall. Lake beds as old as 35,000 years have been found.

Ice rings: Similarly, glacial ice has layers that indicate changes in seasons. Ice cores have been drilled in ice as old as 740,000 years.

Using the simple skills of visual observation and counting, tree rings, lakebeds, and ice cores place the earth well past the 6,000 to 10,000 year age proposed by Young Earth Creationists. Using patterns in the orbit of the earth and patterns of magnetic field reversals, we find dates for the earth going back 30 million to 170 million years (Language of Science and Faith, pp. 62-63).

Dating methods for the way way back – radioactive clocks: In the nucleus of an atom are particles called protons and neutrons. Usually an atom will have equal numbers of protons and neutrons, and all is happy and stable in the atomic world. Sometimes, however, there are extra neutrons in the nucleus of an atom, making the atom unstable. Atoms will “throw off” the extras protons to form a more stable atom.

For example, atoms of uranium-235 are unstable. Uranium-235 will throw off neutrons until it has changed into a more stable element, lead-207.

We know how long it takes for unstable uranium to decay into stable lead. When we want to date a rock containing uranium-235 and lead-207, we can measure the ratio of uranium-235 to lead-207 and determine the age of the rock. Using the uranium-lead clock, the age of the earth is about 4.566 billion years old.


The heavens declare the glory of God;
    the skies proclaim the work of his hands.
Day after day they pour forth speech;
night after night they reveal knowledge

(Psalms 19:1-2)

Everything in the cosmos pours forth speech and reveals knowledge.  Do you believe the speech is true? Do you believe the knowledge is Truth? Do you believe that the cosmos actually is what it reveals itself to be?

Three Kinds of Creationists

Young Earth Creationists: Young Earth Creationists (YEC) believe that Genesis is a scientific and historical account of origins. Adding up genealogies (the begats) and assuming seven literal 24-hours days of creation, YEC conclude that the earth is less than 10,000 years old.  These assumptions are based almost entirely upon English translations of the Old Testament. Many scholars in Hebrew, Old Testament, and ancient cultures insist that the YEC position is not even close to what the text of Genesis is saying.

Old Earth Creationists:Old Earth Creationists (OEC) also believe that Genesis is a scientific and historical account of origins, but they accept scientific evidence for the age of the earth. Although OEC allow for an earth that is billions of years old, OEC believe that living things were created by direct and separate events – no natural processes were involved and they reject evolution.

BioLogos: The view of the authors of The Language of Science and Faith and many Christians who want to be biblically based and scientifically accurate is BioLogos: God’s creative activity is executed within the natural order (Language of Science and Faith, p. 72), using and respecting established natural laws.

Reading Genesis

A literal reading has not been widely accepted as the only way to interpret Genesis for most of the history of the church. Important Christian writers like Origen, Augustine, and Aquinas, although all lived in a pre-scientific time, did not support a literal reading. Even William Jennings Bryan, famous for arguing against evolution in the Scopes trial, did not believe in a young earth.

The Genesis Flood, published in 1961, was wildly popular in evangelical circles and was responsible to a great extent for defining the terms that still exist: serious, Bible-based Christians believe in a young earth and special creation. Deny any aspect of a literal interpretation, and your faith is suspect.


In an auspicious courtroom in 1633, one of the major players in the scientific revolution faced an inquisition by Church authorities. Galileo Galilei was on trial for heresy. Galileo wrote and taught that the sun, not the earth, was the center of the solar system – an obviously false idea because it is directly contradicted by the clear teaching of scripture: The Earth Does Not Move.

After all, Psalm 104:5 says:

He set the earth on its foundations; it can never be moved.

Although Galileo eventually recanted (with fingers crossed behind his back) rather than face the full penalty of the Inquisition, it wasn’t long before his clearly observable astronomical discoveries were widely accepted by Christians.

New science discoveries, new evidence, new data – Christians were compelled to reexamine a biblical text – and faith survived.

Twenty-first century Christians are faced with the evidence that much of life lived and went extinct before humans came along, with Darwin’s discoveries, with evidence of the Big Bang, and with the genetic evidence that all species are related.

These are our Galileo moments.

This series is a chapter by chapter discussion of The Language of Science and Faith by Karl W. Giberson and Francis S. Collins, with commentary and my observations.


I believe that the heavens declare the glory of God.
I believe that day after day the cosmos pours forth speech and night after night the cosmos reveals knowledge.
I trust that the evidence and knowledge that is revealed is true because the Creator of the cosmos is Truth.

Do I Have to Believe in Evolution?

Do I Have to Believe in Evolution?

The 1925 Scopes trial in Dayton, Tennessee, spawned theatrics inside the courtroom and out.  Ministers preached on street corners, vendors sold souvenirs, girls carried monkey dolls, and a chimpanzee named Joe Mendi sipped a Coca-Cola in the drugstore wearing a plaid suit, a brown fedora and white spats.

The trial inspired several popular songs, including this catchy hit (be sure to play the audio – you’ll be humming it all day!)

monkey music cover

Thus was set the adversarial context that defines the debate to this day: do you believe a bunch of unproven so-called scientists, or do you believe the truth in the Bible? Few theological discussions among Christians incur the level of heart-racing blood-pressure-spiking defensiveness as a discussion of evolution.

Opinions usually cluster around one of two poles:

  • An energetic denial of all evidence of evolution accompanied by a literal interpretation of Genesis OR
  • A passive stance – “It doesn’t really matter to me how God did it, I just believe he did it. I don’t want to think about it.”

Regardless of which pole you most nearly orbit, when there is near universal agreement by scientists that evolution is true, it is worth seriously considering.

What does the theory of evolution say?

Evolution is often dismissed because it is “just” a theory. It is important to understand what scientists mean when they use the term theory.  A science theory does not have the same meaning as the word “theory” used in casual, non-technical language. For example:

I have a theory that the Rangers will be in the world series again. (casual and hopeful)

Because of the theory of gravity, jumpers use a parachute when they jump out of a plane. (science)

When scientists use the word “theory”, they are not talking about a best guess, or even an educated guess. When scientists use the word “theory”, they are not implying speculation.

A science theory is a statement of the facts, laws, and principals of something known or observed.

Surgeons scrub before surgery because of germ theory. Jumpers use parachutes because of gravitational theory.

Would anyone suggest surgeons do not need to scrub because germ theory is “just” a theory?

Concisely, evolution theory states that all life on earth evolved from one primitive species that branched out over time, throwing off many new and diverse species. The mechanism that drives most of evolution is natural selection (Why Evolution is True, J. Coyne, p. 3).

It is also important to note what the theory of evolution does NOT say:

  • Evolution theory says nothing about the origin of life.
  • Evolution theory says nothing about the purpose of life.

This is the theory of evolution in a nutshell – the BioLogos worldview – and the grand story of the creative world God brought into existence (The Language of Science and Faith, p. 37).

Why do we often hear that there is not a consensus regarding evolution?

It is important to understand that tweaking a theory or refining details of a theory is not the same as rejecting the theory. Scientists may have differing ideas about details within a theory, but that is not the same as repudiating an entire theory. This is the process of science – constant tweaking, refining, adding to the body of knowledge.

While there are scientists that reject evolution, these are not premier scientists. Looking at the actual names of individuals, we rarely find a contemporary biologist currently working and researching in the field. The names are primarily academics outside of the field of biology and emeritus (retired) faculty, no longer active in research (pp.30-34).

The scientific community is not abandoning evolution – not even close. Theodosis Dobzhansky’s 1973 observation still stands strong:

Nothing in biology makes sense except in light of evolution.

Genetics 101

The basic units of heredity are called genes and are passed from parents to offspring. Genes are made of a substance called DNA.

Molecules in DNA have flexibility to change and move around on a long chain. These “changes and movings” are called mutations. When genes change, a change occurs in the plant or animal. Sometimes the plant or animal is changed in an important way, but most of the time, these changes are minuscule and irrelevant.

If a certain animal group undergoes a substantial number of changes, then the group can eventually turn into a new type of animal – a new species.

But here is a key point: species change very slowly.

We can’t watch a species change.

The term for the unimaginable past is deep time. The inability to imagine this change process and the vastness of the time required often makes people doubt its validity. However, our limitations are not nature’s limitations:

We have to distinguish between challenges to our imaginations, which have trouble conceptualizing slow process that take millions of years, and challenges to nature, which have no such limitations (p. 46).

Sometimes these changes are useful or beneficial. The change might result in an animal being more attractive to a mate. peacock

The change might result in an animal laying eggs that are better camouflaged or that are less fragile than before. In the cases of an attractive mate or hardier eggs, the changes are likely to result in more offspring for the new species. More offspring means more animals with the new trait. If the change happens to be harmful (weaker eggs, for example), then less offspring will result.

Interestingly, changes can be beneficial in one circumstance and harmful in another. The mutation that causes sickle-cell anemia also protects against malaria.

What is the best proof that evolution has occurred?

Even before Darwin, many scientists believed that life had changed over time. Others had previously proposed the idea of evolution. Darwin is considered the originator of evolution because his copious discoveries contributed concrete evidence that change had indeed occurred.

The Human Genome Project (headed by Dr. Collins) finished mapping the human genome in 2003. We now know the DNA code of humans and many other vertebrates. Genetic data from these studies conclusively fit the model that all life evolved from a common ancestor.

Take your vitamins. Most mammals do not need to have vitamin C in their diets because they have a gene that allows them to produce their own vitamin C. However, primates (including humans) need vitamin C in their diets because they cannot produce their own vitamin C. Without vitamin C, primates (including humans) will develop scurvy.

Genetic mapping revealed that primates (including humans) actually have the vitamin C-making gene, but it is “broken” – it has degenerated.

Did God create humans independently and insert a broken gene into our genomes? Giberson and Collins do not find this scenario plausible (Language of Science and Faith, p.43) – and I have to agree.

Over and over again, we find that the genomes of different organisms have the same genes. Some have suggested that God might have “reused” the same DNA pattern for similar creatures. But consider:

The genomes of organisms do not merely share common genes that successfully perform their intended functions. Genomes also share genes that are broken (Language of Science and Faith, p.49).

Did God specially and individually create animals and plants that show evidence of being related… but really aren’t related at all? Is this explanation consistent with your concept of God?

“You may have come from a monkey but I didn’t.”

Did we come from monkeys?

Short answer: NO.

All life on our planet evolved from an original common ancestor, but we did not “come from” a monkey or any other species currently alive on earth.  Humans share a common ancestor with primates, but the human part of the family split off an unimaginably long time ago.


This series is a chapter by chapter discussion of The Language of Science and Faith by Karl W. Giberson and Francis S. Collins with my observations and commentary.


I believe that the heavens declare the glory of God.
I believe that day after day the cosmos pours forth speech and night after night the cosmos reveals knowledge.
I trust that the evidence and knowledge that is revealed is true because the Creator of the cosmos is Truth.

The Language of Science and Faith – Introduction

The Language of Science and Faith – Introduction

It was an evolution of sorts in adhesive chrome-plated automobile accoutrement.

First there was the primitive Christian fish, simple and unadorned. The next permutation was the same little fish, but now sporting legs and feet with the name “Darwin” across its belly. The final model was the Christian fish emblazoned with “Truth” in mid-swallow of the “Darwin” fish. Ha! Top that.

darwin christian fish

The clear implication is that faith and Darwin are completely incompatible, and more than that, Christianity completely trumps, no, obliterates, Darwin.

 According to the Truth Eating Darwin model, here are your choices:

(1) Reject a vast body of science evidence or

(2) Reject God.

A common perception is that to accept scientific explanations of the origins of the universe and life on earth means a rejection of God. Serious Christians don’t believe in evolution, serious scientists don’t believe in God.

 In many Christian circles, particularly evangelical ones, scientific evidences for origins are ignored, or worse, belittled. A radio ad currently running in the DFW market (a secular, “family-friendly” station) warns:

Every time your child picks up a secular textbook they are exposed to agendas, propaganda, and inaccuracies.

 Science isn’t just wrong. Science is an enemy.

For the Christian who wants to love God with heart, soul, and mind, rejection of either science or God is an impossible choice.

In the introduction, the authors of The Language of Science and Faith make this optimistic declaration:

The good news is that we do not have to make this choice (p. 18)

 Three Beliefs About Origins

Theistic evolution is the belief that God created the universe and all life using natural processes (including evolution), within the natural order and within natural laws. On a smaller scale, almost everyone believes this idea: we pray to God to send rain, but we completely understand that rain is a result of the water cycle – a natural process. Francis Collins coined the term BioLogos, combining two key elements of this belief: bios referring to life; logos referring to the Word or rationality of God, as in “in the beginning was the Word (Logos)…”. Dr. Collins founded The BioLogos Foundation, a forum for peer-reviewed scientists to write and speak about science and faith.

 Young Earth Creationism is the belief that Genesis 1-2 are literal, historical accounts of creation. The universe and all that is in it was created in six literal 24 hour days. Ken Ham and his Answers in Genesis are leading advocates of this idea. Young Earth Creationists believe that the universe is less than 10,000 years old.

 Old Earth Creationism is the belief that most of Genesis 1-2 is literal, but the time periods (seven 24-hour days) are not. Old Earth Creationists are open to interpreting days as “geological epochs”. The organization Reasons to Believe is the standard bearer for this belief. A subset of sorts of Old Earth Creationism is the Intelligent Design movement. Intelligent Design (ID) doesn’t directly appeal to Genesis, but maintains that creation is the result of an “intelligent agent”. The Discovery Institute is the primary source for information about ID.

 A Bad Rep

Mentioning “evolution” in a vaguely positive context often evokes a trigger response of emotion and defensiveness despite the fact that the actual theory of evolution makes no direct statements about God. “Darwinism” is frequently used as a synonym for “godlessness” and “atheism”. Although Darwin’s research is considered a watershed moment in biology, Darwin was not the first nor has he been the last to contribute to the understanding of the process of evolution.

There has been no scientific discovery since Darwin – not one- which has suggested that evolution is not the best explanation for the origin of species (The Language of Science and Faith, p. 21-22).

 The implications of this statement are powerful. It is powerful particularly in the context of Christian belief: to reject evolution is to reject the bulk of accepted biological research and understanding.

God of the Gaps

Isaac Newton is credited with discovering the law of gravity. He accurately identified gravity as the reason why planets orbit the sun. However, Newton could not explain the intricacies of the mechanisms by which orbits are maintained. Because he couldn’t explain the mechanics, Newton deemed them unknowable and concluded that it must be due to the action of God. This is a “god of the gaps” argument – I can’t explain it, so I’ll put God (or the gods) in the “gap”.  A century later when the mechanics of orbits were discovered by Pierre Simon de Laplace, the “God explanation” was replaced by demonstrable physical mechanisms.

Darwin offered biology what Laplace offered physics – a natural explanation for some remarkable phenomena people were explaining by invoking God. Neither of these cases  presents an argument against the existence of God” (p. 23).

Should serious Christians be afraid to go down this track? Is it a slippery slope to eventual disbelief in things like miracles, the resurrection and other basic tenets of faith? Is it wise to do as Peter Enns suggests and meet the fear head-on?

Perhaps the way forward is not to resist the slide so much as to stop struggling, look around, and realize that we may have been on the wrong hill altogether (Peter Enns, The Evolution of Adam, p. 145).

Many Christians as well as some of the new atheists claim that to accept evolution is to embrace atheism. Why do you think such opposite camps agree on this point?

Welcome to the discussion. I’ll present the high points of each chapter with commentary and my observations. Comment, discuss, “like”. Jump in!

This series is a chapter by chapter discussion of The Language of Science and Faith by Karl W. Giberson and Francis S. Collins with my observations and commentary.


I believe that the heavens declare the glory of God.
I believe that day after day the cosmos pours forth speech and night after night the cosmos reveals knowledge.
I trust that the evidence and knowledge that is revealed is true because the Creator of the cosmos is Truth.