One of the wonders of our planet is its magnetic field, without which the earth would not be habitable. The earth’s magnetic field acts as a shield to protect us from the intense harmful radiation of the sun, whose super-charged particles would eventually strip our planet of its atmosphere. But our magnetic field also presents strong evidence for a much younger age of the earth than some scientists propose …
Magnetic fields are generated by electrical currents in conductors, and these currents are greatly boosted in the presence of ferromagnetic substances such as iron and nickel – of which the earth’s core primarily consists. Scientists have been able to determine that our planet has a hot solid core of ferromagnetic metal at its heart, surrounded by an outer molten core of the same material (the pressure at the centre being too great for liquids to exist). Strangely, they have been able to determine this by measuring shockwaves from earthquakes. By measuring the residual P-waves (which can travel through solids and liquids) and S-waves (which can only travel through solids) at various places around the earth after an earthquake, a sonic map of the earth’s core has shown it to have a perfectly spherical solid inner core (1,221 km thick) and a perfectly spherical outer liquid core (2,250 km thick).
Furthermore, the earth’s strong magnetic field is proof that the molten outer core is in movement around the solid inner core. Strong convection currents, moving at speeds of possibly thousands of kilometres per hour, are driven by heat from the inner core and are formed into circular or spiral patterns of movement by the Coriolis force from the earth’s rotation. These currents create the movement of charged particles that produces an electrical current. As this electrical current flows around the solid metallic inner core, a strong magnetic field is produced.
The earth’s magnetic field extends thousands of kilometres into space and forms an invisible defence shield called the magnetosphere. The magnetosphere deflects the majority of harmful charged particles from the sun (known colloquially as the ‘solar wind’) and even accelerates them away from the earth. Without our protective magnetic shield, the solar wind would eventually strip our planet of its atmosphere and render our planet uninhabitable – much like Mars is today.
But the magnetosphere is not uniform. It is strongest at the equator and weakest at the poles. This is because the lines of force from the earth’s magnetic field loop around the earth from pole to pole, so that the magnetic lines of force are almost vertical at the poles and are closer to the earth’s surface at those points.
This means that the charged particles from the sun are able to briefly penetrate the upper atmosphere of the earth around these polar regions – penetrating to within 100 km of the earth’s surface. In these regions, solar particles travelling at thousands of kilometres per second slam into atoms of oxygen and nitrogen in the atmosphere, heating them up, stripping electrons from their atoms and creating a glow in the sky, known as the aurora. Oxygen and nitrogen atoms give off different colours when super-heated, giving rise to the diverse colours within the aurora.
As beautiful as these southern and northern lights are, they are a reminder of the deadly radiation that the earth is constantly bombarded with and which our magnetic shield is protecting us from.
One lesser-known fact is that our magnetic shield is slowly weakening. Measurements of the earth’s magnetic field over the last 180 years reveal an exponential (accelerating) decay of the field strength. If we extrapolate this decay back into the past, we find that only a few million years ago the current would have been so great that the heat generated by the electrical resistance would have melted the earth! Obviously, this did not happen, but it shows that the earth cannot be 4.56 billion years old as some scientists suggest.
When this research revealing the decaying magnetic field was first published it created a problem for ‘old age earthers’. They solved this problem by positing that perhaps the earth’s magnetic field goes through periodic reversals, possibly every 300,000 years or so. According to this theory, the gross dipole magnetic field gradually fades to zero, then gradually starts back up again, building to maximum intensity and regenerating an opposite polarity, before beginning to fade once more in an endless cycle of gradual reversals.
There are several huge problems with this theory. Firstly, the theory arises from wishful thinking rather than from hard evidence. Scientists did not discover evidence of past polarity reversals and then formulate the theory. Instead, they formulated the theory as a means of propping up a belief in a very old age for the earth, which was, in turn, necessary in order to allow sufficient time for the extremely slow evolutionary processes which supposedly led to a single celled organism eventually evolving into a PhD scientist. Since formulating this theory of periodic polarity reversals, scientists have desperately sought evidence to prop up this assertion, but all attempts to do so have resulted in, at best, highly speculative interpretations of obscure geological findings which have the ring of desperation about them.
The second problem with the polarity reversal theory is that there is no known scientific mechanism whereby such a reversal could occur. Such a reversal would require a mechanism to regenerate the current each time after it dissipates to zero and there is simply no such known mechanism.
Thirdly, as well as lacking any mechanism to rejuvenate a decayed magnetic field, the polarity reversal theory would also result in many thousands of years with no current at all (and therefore no magnetic field), surrounded on either side by many more thousands of years of extremely weak current as the field either decayed or rejuvenated. During these millennia, the earth would have been unprotected from the solar winds, and over the course of the supposed 4.6 billion years of its existence, our atmosphere would have been completely stripped away long ago.
The fact that we are still here today with a life-giving atmosphere tells us that this supposed polarity reversal cycle did not happen and is a myth concocted from desperate wishful thinking rather than from real evidence-based science.
The exponentially diminishing strength of the earth’s magnetic field is one of many scientific evidences of a relatively young age for the earth. (The longevity of our sun, with its diminishing nuclear reaction is another that is worth reading about).
So, next time you either visit the aurora lights in person or see images of them, give thanks to God for the marvellous protective shield within which he has cocooned us. The aurora lights are a visible manifestation of the protective hand of an all-powerful, loving Creator.
“The heavens declare the glory of God; the skies proclaim the work of his hands. Day after day they pour forth speech; night after night they reveal knowledge. They have no speech, they use no words; no sound is heard from them. Yet their voice goes out into all the earth, their words to the ends of the world.” (Psalm 19:1-2)
 One such evidence is the appeal to different magnetic field orientations within rock crystals, supposedly revealing rocks that were formed during different phases of the earth’s polarity. But these variations are very easily explained by several other models including a more recent creation of the earth followed by a worldwide flood. (See, Danny R. Faulkner, Master Books, Green Forrest, 2017,“The Expanse of Heaven”, p.88)