Radiometric Dating and the Age of the Earth

Short Answers to Big Questions: Part 6

by on

“Doesn’t radiometric dating prove that the earth is millions of years old?” Not in the least. Actually most dating techniques point to a very young earth, and only a few radiometric-dating methods suggest an old earth.

It cannot be overstated that no one looks at isotopes and measures age. Secularists measure the amounts of the radioactive parent and the daughter isotopes in the present; make a whole host of unprovable, naturalistic (anti-biblical and therefore biased) assumptions; and extrapolate backwards in time to make what is essentially a guess about an age. Here’s a quick look at the assumptions that drive the millions of years conclusion.

Secularists today assume uniformitarianism, an idea that the present is the key to the past. The rate at which things happen now is the way they have always happened in the unobserved past (and although they accept that a few catastrophes occurred in the past, they reject what the Bible says of the major catastrophe that wiped out much of sea life and almost all terrestrial life—the global Flood). For example, they assume that rates of radioisotope decay, measured for less than a hundred years, have been the same for millions or billions of years into the past.

This is a gigantic, unverifiable, faith-based assumption in the religion of naturalism—the religion veraciously proselytized by secularists. They are automatically assuming no special creation by God or the global Flood judgement as clearly described in the Bible. These events would likely affect the initial amounts of elements and their isotopes within a rock, the radioactive decay rates, contamination, and so on. Notice, they are assuming the Bible is wrong before engaging the evidence, explicitly revealing their naturalistic bias when evaluating Biblical claims.

So even if radiometric dating worked perfectly, it cannot prove millions of years because of the atheistic assumptions behind it. But many actual results are the opposite of perfect. Radiometric dating persistently gives wildly inaccurate dates for rocks of known age (and it’s often possible to attain any desired general age for a rock, depending on which radiometric dating method you use or the number of times you date a specimen)!

Take, for example, the North American volcano Mount St. Helens, which erupted several times in the early 1980s. One of the results was a new lava dome which formed in the crater of the volcano. One of the lava flows that formed the dome was observed to erupt, cool, and solidify into rock in 1986 (supposedly starting the radiometric dating “clock”). A sample of this rock was dated using the potassium-argon radiometric method in 1996, and dated as high as 2.8 million years old when the rock was observed to be only ten years old!1

Examples of this sort of egregious error are legion. If we can’t trust the radioisotope dating method when dating rocks of known age, how is it plausible to trust it when dating rocks of unknown age?

Bottom line, do we trust the conclusions of fallible men, who weren’t there, who don’t know everything, who start with atheist assumptions about the past (whether they realize it or not)?

Or do we trust the Word of God that is confirmed by real science, is the ultimate authority in all things, and that reveals the clear, eyewitness account of the Creator Himself?

Whom will you trust?

For an audience of One,


  1. Keith Swenson, “Radio-Dating in Rubble,” Answers in Genesis, June 1, 2001,


Get the latest answers emailed to you or sign up for our free print newsletter.

Answers in Genesis is an apologetics ministry, dedicated to helping Christians defend their faith and proclaim the gospel of Jesus Christ.

Learn more

  • Customer Service 800.778.3390