Creation vs. Evolution

Determining the age of the Earth - Evolutionist perspective

The age of the Earth is important to the theory of evolution, because in order for evolution to occur, millions of years are needed. If the Earth is only 7-10 thousand years old as Creationists claim, then evolution cannot be true. This is why this is a major topic in the evolution vs. creation debate.

How Old Is The Earth, And How Do We Know?

Scientists use several methods to determine the age of the earth.

• Erosion. Scientific observation shows that erosion takes place at about 1 ft. every 5,000 years. Knowing this method, we can estimate the age of rock formations like the Grand Canyon. If the Canyon started out flat, it would take 30,000,000 years for the Colorado river to erode 600 ft of the Grand Canyon.
• Sedimentation. Another method used is to measure the rate at which sediment is deposited. Scientists think it takes between 500 and 10,000 years to deposit 1 foot of sediment. This method is not as accurate as the erosion method.
• Salinity of the oceans. Some geologists try to measure the age of the earth by the amount of salt in the ocean. First they need to find out how much salt is in the oceans. Then they find out how much salt rivers carry into the oceans each year. By comparing how much salt there is in the oceans now to how much is carried in by rivers each year, scientists can estimate the age of the oceans.
• Radioactive method.. One of the methods used is to study the uranium in igneous and metamorphic rocks. Uranium is a mildly radioactive substance that breaks down very slowly to form other elements and eventually lead. Uranium breaks down at a slow and steady pace which cannot be altered by temperature or pressure. Scientists calculate that it takes about 5 billion years for a half of a piece of uranium to become lead. By looking at different rocks and comparing the amount of uranium still in the rock to the amount of lead that has been formed, they can measure the age of the earth. Using this method, scientists have determined that the earth is 4-5 billion years old.
• Carbon-14 dating. All organic life forms have some amount of carbon-14 in them. When they die, no more carbon-14 is produced but instead the carbon-14 begins to slowly break down. Scientists think it takes 5,600 years for half of a piece of carbon-14 to break down. The fossil remains of creatures that had carbon-14 in them are found in sedimentary rock. By comparing the amount of carbon-14 in a rock to the amount of other substances that have been formed as a result of the breaking down of the carbon-14, scientists can date the rock. Carbon-14 dating is used to find the age of rocks up to 15,000 years old and the radioactive method is used for older rocks.

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This web site is a 1998 ThinkQuest Contest Semi-Finalist. Copyright © 1999 ThinkQuest Team 19012. All rights reserved. Last modified: Friday August 28, 1998.