http://www.ck12.org Chapter 5. Energy
5.81 Magnetic Field Reversal
- Describe a magnetic field reversal.
- Identify evidence for magnetic field reversals.
Do you like science fiction? This is a fictional scene that is set in the future. Science fiction artists are so creative!
They might even describe a time when compasses point south instead of north. Actually, this idea isn’t fiction—it’s
a fact.
Changing Places
Earth’s magnetic poles have switched places repeatedly in the past. As you can see in theFigure5.177, each time
the switch occurred, Earth’s magnetic field was reversed. Themagnetic fieldis the region around a magnet over
which it exerts magnetic force. We think of today’s magnetic field direction as “normal,” but that’s only because it’s
what we’re used to. You can watch a simulation of a magnetic field reversal at this URL: http://www.pbs.org/wgbh/
nova/earth/when-our-magnetic-field-flips.html