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# A Lesson from an Hourglass

Genesis 5:5,8
Thus all the days that Adam lived were 930 years, and he died….Thus all the days of Seth were 912 years, and he died….

Calculating the age of the earth, from empirical data, requires presuppositions. The scientists, who calculate the age of rocks using, for example, uranium-lead dating, are intelligent people, and completely capable of performing careful experiments. Their care, coupled with their technology, means that they make highly accurate measurements of the amounts of uranium and lead. But these measurements do not directly give us the age of the rock. In order to calculate the age, we must make three assumptions:

1. That there was no lead in the original rock.
2. That no lead was either added to or removed from the rock at any time.
3. That the half-life of uranium has never changed. The half-life gives us a handle on the rate of change of uranium to lead.

Imagine you find an hourglass on a desk. In order to calculate how long the hourglass has been running, you might measure the amounts of sand in the upper and lower chambers, and the rate at which the sand is flowing. Using this data, you could confidently calculate how long ago the hourglass was set up. But you do not know if all the sand was in the top to start with, and you do not know if the glass was shaken to speed up the rate of flow. Different assumptions give you a different answer, so the only reliable way to know the age of the earth is to use the information God gave us in the Bible.

Prayer:
Our thoughts are lower than Your thoughts, Lord. Help us to remember that You have given us so much information in Your word. May we not consider that we know better than Your word. Amen.

Notes:
Taylor, P.F. (2015), The Biblical Age of the Earth, (Toutle, WA: J6D Publications)