Dan Lathrop has built his fourth “baby Earth”, a model designed to help better understand our planet’s magnetic forces. The previous version was just two feet in diameter, and failed to generate a magnetic field of its own. The new model is ten feet across, and will spin at 145 kph. Dan and his team are hoping that this will be big enough to create a magnetic field, and lead to some understanding of how this aspect of Earth ticks.

Of special interest is magnetic pole shifts – what causes them, and when will the next one be. In an interview Dan suggests that we would have a century or two up our sleeves to prepare. Hopefully Dan’s experiment will have results prior to 2012…

• Article at NPR
• Dan’s Lab site