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Origins: Creation science & evolution

About fossils, the length of the
day and the age of the earth

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About the age of the earth, and why it is so important:   You may wish to skip this introduction if you are familiar with old and new earth beliefs.

Many creationists and scientists disagree about the age of the Earth. The most vocal creationists believe in a young earth -- one that has been in existence fewer than 10,000 years. All of the scientists that we have heard of, who are not young earth creationists, believe that the earth is much older -- over four billion years.

bulletOld earth belief:
bullet Over 99.8% of specialists in the biological and geological sciences support the theory of evolution. This implies a very old earth. A near universal estimate, based on radiometric measurements of earth rocks, is that that the earth coalesced into more or less its current shape about 4.5 billion years ago.

bullet Many "Old earth creationists" believe that God inspired the authors of the Bible to write text that is inerrant -- free of error. They interpret Genesis 1 and 2 in the Hebrew Scriptures (Old Testament) as implying a very old universe. They generally accept the scientists' estimate of a  universe coming into existence approximately 15 billion years ago and a roughly 4.5 billion year old Earth. They believe that God created both.

bullet Young earth belief: Many, perhaps most, Christian Creationists are "young earth creationists" who view the Earth and the rest of the universe as less than 10,000 years old. Conservative Christians have made many calculations have been made to estimate the date of creation. We have found dates ranging from 3641 to 6000 BCE. A common estimate for creation is 4004 BCE; this implies a 6 millennia-old earth. However, some young earth creationists suspect that some of the generations between Adam and David were simply not reported in the Bible. That is, when the Bible states that A begat B, then A might have been really the grandfather, not the father, of B. This could push the date of creation, according to their interpretation of the Bible, back perhaps to sometime between 4000 and 8000 BCE -- as much as ten millennia before the present time.

The difference between ten thousand years and 4.5 billion years is enormous. It is roughly like comparing the thickness of a piece of paper with the length of a football field!

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Calculation of the earth's rotational speed:

There are at least three methods of estimating the rotational speed of the earth as it existed in the distant past; one technique goes at least as far back as 2 billion years ago. This is almost half-way to the time when the earth coalesced according to scientists, but 200,000 times as long as the earth has existed according to young earth creationists:

bullet Fossil bivalves and coral: One well known indicator of an old earth are the daily and yearly growth rings on rugose coral fossils. One group of fossils had been dated as 370 million years old, using radiometric analysis. Analysis of their growth rings indicated that there were about 425 days in each year when the coral was alive. This means that each day was only about 20.6 hours long when the coral was alive. As we go back in time, if we assume that the deceleration rate was constant at its present rate, a day would have shortened by about 11 microseconds each year. This would be 1.1 hours over 370 million years. One would have expected a 23 hour day if the corals were 370 million years old. Thus, we can conclude that the two unrelated methods of estimating the age of the corals gave values that were reasonably close.

bullet Stromatolites: Another indicator is a stomatolite at Zhoukoudian, Beijing, China. It is a sedimentary structure mainly composed of blue-green algae which has formed "bright and dark laminas." They show yearly patterns much like rings in trees. They found that one billion years ago, a year was composed of about 516 days. Each day would have been on the order of 17 hours long. 1

bullet Fossil tidal rhythmites: These are tidal sedimentary rocks formed from cyclical deposits of sedimentary material. They form layers as a result of the tides. 2

An article on the CreationWiki web site has collected twenty-seven direct measurements of the number of days in a year over the past two billion years using these three methods:


The red data points are from fossil bivalves and corals; the two blue points are from fossil tidal rhythmites; the six green points are from stromatolites. "Ma" refers to millions of years ago relative to the present time.


Fitting a statistical curve fit to the data, as shown in magenta, one can compute that the earth's deceleration. The author of the CreationWiki essay estimates a loss of about 0.0132 seconds per year per year.

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Estimates of the earth's rotational speed 4 billion years ago and more:

We have found three articles which give estimates of the length of a day many billions of years ago, close to the time some 4.5 billion years ago when the earth first coalesced. They appear to have been derived from mathematical models of the earth's rotation:

bullet The International Society for Astrological Research (ISAR) estimates the length of a day as about six hours, at a time 4 billion years ago. 1

bullet An article in a popular Canadian newspaper column on astronomy estimates the length of a day at five hours some four billion years ago. We are trying to find the source of that datum. 5

bullet Still another article says that "Most scientists believe that the earth's rotation rate was originally an 8-hour day....A rotation rate of 8 hours would not cause a huge bulge at the Earth's equator. Even if the rate were much higher, any bulge formed at that time would have disappeared within the last 4.5 billion years due to tectonic activity." 6

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Implications for evolution and creation science:

Scientists have estimated the rotational speed of the earth up to two billion years ago from fossils and stomatolites. They have found that a day lasted about 21 hours 370 million years ago, and about 17 hours about a billion years ago. Scientists have estimated a four to eight hour day about 4 billion years ago.

Also, direct evidence shows that the earth was in existence two billion years ago. This contrasts with the creationists' belief that the earth is less than 10,000 years old.

The evidence shows that the rotational speed of the earth was higher billions of years ago than it is today -- but no unreasonably so. Some creation scientists and authors had suggested that the rotational speed of the earth would have been so high that it would have flattened the earth into a pancake.

Fossils and stomatolies allow a direct measurement of the number of days in the year at the time that the fossils and algae were alive. However, measurement of the age of the samples depends upon radiometric analysis. Although the latter technique is accepted as accurate by the vast majority of scientists, creation scientists have rejected it as inaccurate.

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The following information sources were used to prepare and update the above essay. The hyperlinks are not necessarily still active today.

  1. "One Billion Years Ago: Over 500 Days Yearly, 17 Hours Daily," China Education and Research Network, 2004-DEC-21, at:
  2. G.E. Williams, "Tidal Rhythmites - Key To the History of the Earth's Rotation and the Lunar Orbit," Journal of Physics of the Earth 38(6): Pages 475-491, 1990.
  3. "Claim CE011: Earth's rotation is slowing down, so it cannot be more than a few million years old." CreationWiki, at:
  4. This image is reproduced here under the terms of the GNU General Public License. See the GNU Free Documentation License at:
  5. Terence Dickson, "The expert spin on Venus," The Toronto Star, 2005-JUL-13, Page B7.
  6. "The Slowing of the Earth's Rotation Rate Means the Earth Must be Young," 2000-DEC-19, at:
  7. CreationWiki uses the same open source software as Wikipedia; however, the two are not affiliated in any way.

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Copyright © 2002 to 2011 by Ontario Consultants on Religious Tolerance
Originally written: 2002-JAN-3
Latest update: 2011-APR-28
Author: B.A. Robinson

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