How Old Is the Earth?

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Where’s the supposed evidence that the earth is 4½ billion years old? It’s not on earth at all!

If you ask this question of most scientifically literate people, they will answer that the earth is about 4½ billion years old. But if you ask biblically literate people, many will answer that it is little more than 6,000 years old. Why the huge difference? We look at the same world but come to different conclusions because our worldviews are different.

To fully understand the issue, we must look beyond this earth. Literally. Let me explain.

The Biblical Date

How do we arrive at the biblical date? The genealogies of Genesis 5 and 11 make it clear that Abraham lived about 2,000 years after the creation. And we know from chronologies found elsewhere in the Bible that Abraham lived about 2,000 years before the birth of Jesus Christ. Furthermore, we know that Jesus’ ministry was about 2,000 years ago. Summing these lengths of time, we get about 6,000 years (technically just a little more).

What Most Scientists Think

How do many scientists arrive at the age of 4½ billion years? They rely on radiometric dating, though the story is a bit more complicated than it sounds. Some rocks contain trace amounts of radioactive atoms. Those radioactive atoms decay into stable atoms over time. By knowing the decay rate and measuring the amount of both kinds of atoms in a rock, scientists can compute the amount of time it took to produce the stable atoms.

Some assumptions are involved, however. Were some of the stable atoms present in the rock to begin with? Did some of either type of atom leave or enter the rock during the time being measured for decay? To make matters worse, measuring the age of a rock by different kinds of radioactive atoms (such as uranium or rubidium) often yields very different ages. There are many examples of such discordant ages.

But even if we accept these ages as correct, there are many other assumptions that cause even more problems. You see, we never find rocks on earth that date back 4½ billion years. The earth is a very dynamic place, with volcanic eruptions and tectonic plate movements that constantly recycle old rocks into new rocks. When rocks are recycled this way, it is believed that their radiometric dates are reset.

So we wouldn’t expect to find the original “primordial” rocks on earth. Instead, scientists must look to other bodies in the solar system that are less active geologically. The search for primordial rocks was one of the scientific reasons we sent men to the moon a half-century ago. Scientists thought that since the moon has far less geological activity than the earth, its rocks would be older.

Indeed, the moon’s rocks generally yield old radiometric dates, but even they don’t yield dates of 4½ billion years. Why?

While the moon is far less active than the earth, that hasn’t always been the case. Most scientists think that the moon was very active early in its history. So while moon rocks have relatively old radiometric dates, they aren’t primordial either. To find truly primordial rocks, planetary scientists think they must look at meteorites, debris that has fallen onto the earth’s surface from somewhere else in the solar system. The 4½-billion-year age of the earth comes from radiometric dating of meteorites.

How can they know these are the earliest rocks? They have a theory that the whole solar system formed at the same time, around 4½ billion years ago. This means the sun and planets would be about the same age. Material that didn’t become part of the sun supposedly coalesced into larger and larger pieces, eventually forming planets and their satellites, or moons. But many of the pieces never formed into planets or satellites. Fragments of these pieces are thought to be the origin of meteorites. Since meteorites didn’t form into planets, they must have avoided the geological process that reset radiometric ages on earth. This is particularly true of the carbonaceous chondrites.

But note all the unproven assumptions. Evolutionary assumptions at that.

The Real Agenda

For decades, scientists who believe the earth is billions of years old have said that radiometric dates are their reason for believing so. But this hasn’t always been the case. The methods for radiometric dating were developed only a hundred years ago. Prior to that, many scientists already believed the earth was billions of years old, not based upon radiometric dates but the assumption that modern life evolved from nonlife. Evolutionists recognize that we can’t see planets and life evolving before our eyes. They say it requires great time; so the earth must be very old.

There is a good lesson here. In the late 1800s, many scientists concluded that the earth must be at least 100 million years old because that was considered the minimum time necessary for evolution to account for the earth’s biology and geology. The need for time drives the claims of ancient dates.

Lord Kelvin, one of the most significant scientists of the 1800s, tested the then-popular age of 100 million years and produced two quantitative tests that showed the earth and sun could be no more than about one-third of this age. Yet his evolutionary colleagues persisted in their belief despite Lord Kelvin’s objections. Since then, many critics have noted that his objections have been explained to their satisfaction. But that misses the point. Many of Kelvin’s colleagues believed in great age despite the evidence, not because of it.

Today many scientists continue to believe in a 4½-billion-year-old earth, which evolution requires. They will continue to choose to believe that age, even though solid scientific reasons are available to doubt those dates.

Our Job

Scientists have found many evidences that the earth is far younger than 4½ billion years, but these are usually swept under the rug.

It is the job of creation scientists to reevaluate scientific claims using their biblical worldview. Scientists have found many evidences that the earth is far younger than 4½ billion years—even as young as 6,000 years—but these are usually swept under the rug.

Creationist literature (including this magazine) is filled with examples. They include the composition of the earth’s atmosphere and seawater, which would be much different if helium had been escaping the atmosphere and salt had been accumulating in the ocean for millions of years. Also, the moon’s tidal interaction with the earth is causing the moon to spiral outward, which limits how long it has been in orbit. (Just go online and search for “evidences of a young earth” for details and more examples.)

Most importantly, we need to point people to the importance of starting in the right place—God’s Word—when interpreting the evidence.

Dr. Danny R. Faulkner joined the staff of Answers in Genesis after more than 26 years as professor of physics and astronomy at the University of South Carolina Lancaster. He has written numerous articles in astronomical journals, and he is the author of Universe by Design.

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