Ecclesiastes 1:10
“Is there any thing whereof it may be said, See, this is new? it hath been already of old time, which was before us.”
Evolutionary geologists find ages for rocks, using a method known as radiometric dating. For example, uranium-lead dating relies on the change of uranium into lead. The rate at which 
uranium changes into lead is not linear, but can nevertheless be measured. This value is called the half-life. If we know the half-life of uranium, and the amount of lead that there was in the rock, when it was formed, then we can calculate the age of the rock, assuming that no lead has been added to or taken out of the rock.
Imagine an hourglass. Sand is flowing from the top to the bottom. You could measure how much sand was in the top of the hourglass, and also how much in the lower part. Finally, you would measure the rate at which sand flows from top to bottom. You might think you could use these values to calculate how long the hourglass had been going, but you would be wrong. This is because you do not know if all the sand started in the top, or if the glass was shaken at some time, making the sand go through faster. In the same way, geologists assume that an igneous rock was formed without any lead in it, but it is impossible to know this. They also assume that the half-life of uranium has never changed. But we now have considerable evidence to suggest that the half-life changed rapidly in the past.
There is, however, a fully reliable method of dating the Earth. This involves using the dates found in the Bible, yielding an age of just over 6,000 years.
Help us, Lord, to weigh everything we know against the truth of Scripture. Thank You for Your word, Lord. We pray that it might guide us into truth. Amen.
Author: Paul F. Taylor
Ref: Humphreys, R. (et al), Radioactivity and the Age of the Earth, (ICR). Image: Adobe Stock image, licensed to author.
