Science in Seconds - Magnetic Fields

Science in Seconds Know Everything RUMOURS – Magnetic Fields Rheanna Sand: Ah, magnetic fields. One of my favorite science topics, and one of my favorite bands. Of course, one is an abstract, nebulous force, not easily explained, and the other is a mathematical description of the influence in electric current on magnetic material. We've all seen magnetic fields in action. There's one that seems to confuse and worry a lot of people. Earth's magnetic field, or magnetosphere, surrounds the entire planet. But some fear that one day the magnetic poles will instantly switch places, wreaking havoc on navigation systems and forcing Canadians to admire the aurora australis, rather than borealis. One thing is correct about that statement: the magnetic poles will switch! ...eventually. Geologists can tell by going down through the layers of rock, and examining the orientation of magnetized fragments, that approximately every few hundred thousand to a million years, the magnetosphere undergoes a pole reversal. And the last reversal to happen was about 780,000 years ago. But fearing this reversal event is silly: Even if the process were to start today, it would take hundreds, or even thousands of years to complete. The magnetic field arises from the flow of molten iron in the Earth's core. And while it's considered fast in geological time, it's nowhere near fast enough to be any concern to us, our grandchildren or our grandchildren's grandchildren. One day, if we haven't destroyed ourselves, there may be people who experience the messy, disordered magnetosphere in flux. Those folks may be at risk for more cancers or random gene mutations from solar wind particles making their way to Earth. But it's safe to say it most definitely will not be you. Courtesy of Science in Seconds – All rights reserved Only for educational/non-profit purposes. (Translators are invited to put their name here)