During a brief but dramatic chapter in Earth's history about 41,000 years ago, the planet’s magnetic field nearly collapsed.

When an electric current passes through a metal wire, a magnetic field forms around that wire (see diagram at right ... and generators to operate. In the Earth (see image below right), the ...

Such is the case with the Earth's magnetic field. Every so often, our planet's magnetic poles reverse polarity (see When Compasses Point South). Compass needles have always pointed north ...

The outer core is liquid iron and nickel and generates the Earth's magnetic field. And the inner core ... made from solid iron and nickel. In this diagram, the red lines represent the edges ...

Back in 1832, the celebrated British physicist, Michael Faraday, carried out a set of experiments designed to answer a tantalizing question: could electricity be generated by Earth's rotation through ...

From there, the other directions can be figured out. Without the Earth’s magnetic field, this useful phenomenon would not occur. Whilst the geographical and magnetic north poles aren’t always ...

This "nano-compass" allows the microbe to passively orient itself in Earth's geomagnetic field (Figure 2). These magnetic nanoparticles ... concentration (top of the diagram) swim forward to ...