How Magnetism Shapes The Universe

How far can you follow a compass needle? As far as the north magnetic pole, where the needle starts spinning wildly? Compass needles align with magnetic field lines, and on the precise spot of magnetic north, those field lines are vertical. So just tilt your compass 90 degrees and you can continue your journey - either down to the molten iron dynamo surrounding the Earth’s core, or up. But up to where? The answer - to everywhere - and today, that’s where we’re going to go.