Get ready to flip the dial on your compass by 180° soon. Well not real soon, but indications point to another
reversal of the Earth's magnetic field reversal in as little as
. To more
accurately investigate the phenomenon, researchers at the U. of MD have constructed a 30-ton sphere that spins at
more than 90 mph to generate magnetic fields. The 10-ft sphere is filled with 13.5 tons of liquid sodium to mimic
the Earth’s liquid-iron center core. A 3.3-ft sphere counterrotates inside the larger one. Both spheres are driven
by 350-hp electric motors. At full speed the outer sphere spins at 240 rpm. The inner sphere reaches 960 rpm.