Like the plot of a science fiction B movie, something strange is happening deep in the constant rotation of liquid metallic core generates Earth’s magnetic force invisible field protects our planet from harmful radiation in space. Gradually, the field is getting weaker. Could we be heading for a demagnetized doomsday leaves us defenseless against the lethal effects of solar wind and cosmic rays? “Magnetic Storm” looks into our potentially unsettling magnetic future.
Scientists studying the problem are looking everywhere from Mars, which suffered a magnetic crisis four billion years, and has been devoid of a magnetic field, an appreciable atmosphere, and possibly life ever since, to a laboratory in the University of Maryland, where a team headed by physicist Dan Lathrop has recreated the molten iron dynamo at Earth’s core by using 240 pounds of highly explosive molten sodium. The most visible signs of Earth’s magnetic field are auroras, which are caused by charged particles from space interact with the atmosphere as it flows toward the north and south magnetic poles.
However, the warning signs of a declining field are subtler-though they are evident in every clay dish that was never fired. During high temperature firing, iron minerals in clay record the exact state of Earth’s magnetic field at that precise moment. By examining pots from prehistory to modern times, geologist John Shaw of the University of Liverpool in England, has discovered how dramatically the field has changed. “When we plot the results of ceramics,” he says, “we see a rapid decline that we have reached our days. The exchange rate is higher in the last 300 years, it has been for some time in the past 5,000 years . going from a strong field to a weak field, and do so very quickly. ”
At the current rate, the Earth’s magnetic field could disappear within a few centuries, exposing the planet from relentless blast of charged particles from space with unpredictable consequences for the environment and life. Other options: the field could stop weakening and begin to strengthen, or it could weaken to the point that suddenly turns polarity, that is, compasses begin to point to the South Magnetic Pole.
