Many independent measurements have established that the Earth and the universe are billions of years old. Geologists have found annual layers in glaciers that can be counted back 740,000 years. Using the known rate of change in radio-active elements (radiometric dating), some Earth rocks have been shown to be billions of years old, while the oldest solar system rocks are dated at 4.6 billion years. Astronomers use the distance to galaxies and the speed of light to calculate that the light has been traveling for billions of years. The expansion of the universe gives an age for the universe as a whole: 13.7 billion years old. (Updated April 16, 2012)

Genesis 6-9 tells the fascinating story of Noah, the Ark, and the Flood. Some Christians interpret the text to mean that the biblical flood must have covered the entire globe. They also work to explain the evidence in rocks and fossils in terms of this world-wide flood. Other Christians do not feel the text requires that the flood be global, but could have covered the small region of earth known to Noah. The scientific and historical evidence does not support a global flood, but is consistent with a catastrophic regional flood. Beyond its place in history, the Genesis flood teaches us about human depravity, faith, obedience, divine judgment, grace and mercy.

In our sixth BioLogos videocast, we take a look at the age of the Earth. We explain four methods scientists have used to determine that age: tree ring, lake varve, radiometric, and seafloor spread dating, and also offer some theological insight on how an old earth can fit with the first chapters of Genesis.

In this brief video, Physicist Ard Louis looks at two important aspects of time to consider when reading Genesis 1: chronology and the idea of “deep time”.

A common argument against biological evolution is that the theory contradicts the second law of thermodynamics. The second law says that disorder, or entropy, always increases or stays the same over time. How then can evolution produce more complex life forms over time? The answer is that the second law is only valid in closed systems with no external sources of energy. Since the Earth receives continual energy from the Sun, the second law does not apply.