If you went to a public high school or college, you were taught that the earth is 4.54 billion years old. That is so precise that it seems it must be right. We aren’t told that the earth is about 4 billion years old. No. We are told it is precisely 4.543 billion years old.

How do scientists know this?

They use something called radiometric dating.

Answers in Genesis (AIG) has an article on radiometric dating. It illustrates radiometric dating with sand in an hourglass (see here). A true hourglass has enough sand to run for exactly one hour. But there are other hourglasses, or sandglasses, that run out in 3 minutes or other amounts of time.

Let’s say you find a huge sandglass running, and most of the sand is in the bottom half. How could you determine how long ago the glass started running? Let’s say you could calculate that 90% of the sand was in the bottom half. You then time the hourglass to find out how long it takes for the final 10% to run out. If that last 10% took one hour, then the 90% took 9 hours and the sandglass started running 9 hours ago. Of course, that assumes that the sand’s rate of flow has been constant over the past 9 hours. Temperature or humidity or differences in the grains of sand might have changed the rate of flow.

It also assumes that nothing disturbed the flow. Someone could have started it 10 years ago but, after it ran for 9 hours, something turned it on its side. Then, just a minute before you arrived, someone set it upright and it began draining again.

Radiometric dating looks at the presence of radioactive atoms (e.g., uranium 238) and what are called daughter isotopes (e.g., lead 206) that are a result of radioactive decay. The uranium is like the sand in the upper chamber and the lead is like the sand in the lower chamber.

This works fine if the following are true: 1) when Earth began there were no daughter isotopes in the rocks (if there were, that would have resulted in what is called apparent age); 2) the rocks were never contaminated by water or lava; and 3) the rate of decay of the radioactive atoms has always been constant. See the AIG article for more details.

AIG writes, “when a sample of the lava in the Mt. St. Helens crater (that had been observed to form and cool in 1986) was analyzed in 1996, it contained so much argon-40 that it had a calculated ‘age’ of 350,000 years! Similarly, lava flows on the sides of Mt. Ngauruhoe, New Zealand, known to be less than 50 years old, yielded ‘ages’ of up to 3.5 million years.” Those examples don’t encourage confidence in radiometric dating.

At the moment of creation, everything had apparent age. For example, when Adam was one minute old, he looked like an adult. When the first trees were one minute old, they probably had rings indicating that they were hundreds of years old. The rocks would have had apparent age, too.

There is no way that science can determine how old the earth is.

But God has told us how old the earth is. In Genesis 5 the Bible provides a genealogy that covers all of Noah’s ancestors, beginning with Adam. And we have other listings that go from Noah to the time of Christ. If there are no gaps in these records, then the creation was around 4200 BC or a little over 6,200 years ago. However, let’s say that in some cases a grandson was listed with his grandfather, thus leaving out a generation. Assuming that were so (though it is not likely), it would only allow for Earth’s age to be a few hundred, or at most a few thousand, years older.

Some Bible scholars think there was a gap in time between Genesis 1:1 and 1:2 and that there could, therefore, have been an unknown number of years before the creation of Adam and Eve. However, even if that view were true (which is highly unlikely; see here for an article by Don Stewart on the gap theory), it would only extend Earth’s age a few thousand years, not millions or billions.

I realize that many Christians believe science has absolutely proven that the earth is over 4 billion years old and that the first humans appeared on Earth around 2 million years ago. Many people who have an interest in the Bible accept those dates, then–in an effort to reconcile them with what the Bible says–come up with various theories about what Genesis 1-3 “really” means. For example, most professors at conservative seminaries today say that Genesis 1-3 presents poetic history, not actual history. They say that we cannot know which events truly happened and which did not. In their view, Genesis 1-3 tells us that God created, but not how He created.

In this view, Adam might not have been created from dust and Eve might not have been created from Adam’s rib. Instead, Adam and Eve might have been born naturally into a race of pre-humans called hominids. Then God breathed on them and gave them souls and they became the first humans. Some Bible scholars say that there were no Adam and Eve at all.

In this view, there may not have been a literal talking serpent or a Garden of Eden or a forbidden fruit. All of these could be poetic devices that simply tell us that God created and that mankind fell, but not how all that happened.

The fact that both the Lord Jesus and the Apostle Paul refer to a literal Adam and Eve should eliminate the poetic history idea. Paul also confirms that when they sinned, Eve was deceived but Adam was not. Many verses in the OT and NT confirm the creation account.

Evolution is a theory that is filled with contradictions. Evolution as an explanation of origins makes no sense. That is why there are thousands of scientists who believe that the earth is just thousands of years old and that Genesis 1-3 reports literal history.

I’m confident that the earth is less than 7,000 years old. I see no scientific evidence that causes me to question that.