The earth is surrounded by a magnetic field that protects living things from solar radiation. Without it, life could not exist. That’s why scientists were surprised to discover that the field is quickly wearing down. At the current rate, the field and thus the earth could be no older than 20,000 years old.

The earth’s magnetic field is wearing down so quickly that it could be no more than 20,000 years old.

Several measurements confirm this decay. Since measuring began in 1845, the total energy stored in the earth’s magnetic field has been decaying at a rate of 5% per century.1 Archaeological measurements show that the field was 40% stronger in AD 1000.2 Recent records of the International Geomagnetic Reference Field, the most accurate ever taken, show a net energy loss of 1.4% in just three decades (1970–2000).3 This means that the field’s energy has halved every 1,465 years or so.

Creationists have proposed that the earth’s magnetic field is caused by a freely-decaying electric current in the earth’s core. This means that the electric current naturally loses energy, or “decays,” as it flows through the metallic core. Though it differs from the most commonly accepted conventional model, it is consistent with our knowledge of what makes up the earth’s core.4 Furthermore, based on what we know about the conductive properties of liquid iron, this freely decaying current would have started when the earth’s outer core was formed. However, if the core were more than 20,000 years old, then the starting energy would have made the earth too hot to be covered by water, as Genesis 1:2 reveals.

Magnetic Field

Figure 1: Creationists have proposed that the earth’s magnetic field is caused by a freely decaying electric current in the earth’s core. (Old-earth scientists are forced to adopt a theoretical, self-sustaining process known as the dynamo model, which contradicts some basic laws of physics.) Reliable, accurate, published geological field data have emphatically confirmed this young-earth model.

Reliable, accurate, published geological field data have emphatically confirmed the young-earth model: a freely-decaying electric current in the outer core is generating the magnetic field.5 Although this field reversed direction several times during the Flood cataclysm when the outer core was stirred (Figure 1), the field has rapidly and continuously lost total energy ever since creation (Figure 2). It all points to an earth and magnetic field only about 6,000 years old.6

Magnetic Field Weakening

Figure 2: The earth’s magnetic field has rapidly and continuously lost total energy since its origin, no matter which model has been adopted to explain its magnetism. According to creationists’ dynamic decay model, the earth’s magnetic field lost more energy during the Flood, when the outer core was stirred and the field reversed direction several times.

Rescuing Devices

Old-earth advocates maintain the earth is over 4.5 billion years old, so they believe the magnetic field must be self-sustaining. They propose a complex, theoretical process known as the dynamo model, but such a model contradicts some basic laws of physics. Furthermore, their model fails to explain the modern, measured electric current in the seafloor.7 Nor can it explain the past field reversals, computer simulations notwithstanding.8

To salvage their old earth and dynamo, some have suggested the magnetic field decay is linear rather than exponential, in spite of the historic measurements and decades of experiments confirming the exponential decay. Others have suggested that the strength of some components increases to make up for other components that are decaying. That claim results from confusion about the difference between magnetic field intensity and its energy, and has been refuted categorically by creation physicists.9

Dr. Andrew Snelling holds a PhD in geology from the University of Sydney and has worked as a consultant research geologist in both Australia and America. Author of numerous scientific articles, Dr. Snelling is now director of research at Answers in Genesis.

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Footnotes

  1. A. L. McDonald and R. H. Gunst, “An Analysis of the Earth’s Magnetic Field from 1835 to 1965,” ESSA Technical Report, IER 46-IES 1 (Washington, D.C.: U.S. Government Printing Office, 1967). Back
  2. R. T. Merrill and M. W. McElhinney, The Earth’s Magnetic Field (London: Academic Press, 1983), pp. 101–106. Back
  3. These measurements were gathered by the International Geomagnetic Reference Field. See D. Russell Humphreys, “The Earth’s Magnetic Field Is Still Losing Energy,” Creation Research Society Quarterly 39, no. 1 (2002): 1–11. Back
  4. Thomas G. Barnes, “Decay of the Earth’s Magnetic Field and the Geochronological Implications,” Creation Research Society Quarterly 8, no. 1 (1971): 24–29; Thomas G. Barnes, Origin and Destiny of the Earth’s Magnetic Field, Technical Monograph no. 4, 2nd edition (Santee, CA: Institute for Creation Research, 1983). Back
  5. D. Russell Humphreys, “Reversals of the Earth’s Magnetic Field During the Genesis Flood,” in Proceedings of the First International Conference on Creationism, vol. 2, R. E. Walsh, C. L. Brooks, and R. S. Crowell, eds. (Pittsburgh, PA: Creation Science Fellowship, 1986), pp. 113–126. Back
  6. For a fuller treatment and further information see:
    John D. Morris, The Young Earth (Green Forest, AR: Master Books, 2000), pp. 74–85;
    Andrew A. Snelling, Earth’s Catastrophic Past: Geology, Creation and the Flood (Dallas, TX: Institute for Creation Research, 2009), pp. 873–877. Back
  7. L. J. Lanzerotti, et al., “Measurements of the Large-Scale Direct-Current Earth Potential and Possible Implications for the Geomagnetic Dynamo,” Science 229, no. 4708 (1985): 47–49. Back
  8. D. Russell Humphreys, “Can Evolutionists Now Explain the Earth’s Magnetic Field?” Creation Research Society Quarterly 33, no. 3 (1996): 184–185; Back
  9. D. Russell Humphreys, “Physical Mechanism for Reversal of the Earth’s Magnetic Field During the Flood,” in Proceedings of the Second International Conference on Creationism, vol. 2, R. E. Walsh and C. L. Brooks, eds. (Pittsburgh, PA: Creation Science Fellowship, 1990), pp. 129–142. Back