The Core and Electromagnetism
Perhaps one of the more interesting movies electromagnetically speaking is The Core. The basic premise of the movie is that the Earth’s outer core, supposedly the third layer of what makes up the planet, which is believed to be in constant motion, has stalled due to human interference. As a result, the electromagnetic field that surrounds the earth protecting it from the destructive power of the Sun’s cosmic rays has become unstable, creating earthquakes, electrical failure, and general breakdown of basic electronic technology, including pacemakers. The disruption has also caused birds to lose their sense of direction and sends them careening into stone statues to die in front of small children in parks. The mission of the protagonists is to jump start the planet by detonating a series of nuclear bombs at strategic points in the liquid iron of the outer core.
The Earth does have a protective magnetic field around it that protects the surface from being inundated by powerful solar rays that can cause, at the least, serious personal injury from radiation. People are sometimes also injured or contract illnesses from man-made radiation sources. An electromagnetic field is generated from the motion of charged particles, and in the case of the outer core, it is the extremely high heat that sets the charged particles in motion. It is also true that this continuous motion of the liquid metal in the outer core does generate this protective field, which extends to about 78 miles up from the crust (surface of the Earth). Occasionally, fluctuations in the field let in more cosmic rays than usual, affecting communications, power grid networks, and satellite reception, which was demonstrated in the first part of the movie.
It should be noted there are some points in the movie that reeks of bad science, such as the existence of amethysts in the mantle, which is in turn posited to be mostly empty space. While scientists have yet to penetrate to the mantle, known scientific facts make these suggestions highly improbable. However, the movie does base most of its propositions on sound principles, save for the fact that the motion of outer core could be stopped or restarted with existing technology.