If shrunken down to micron size, a compass needle could wobble. (Courtesy: iStockphoto/tobias machhaus) A tiny magnetic needle just 10 μm long could be used to create a magnetic-field sensor that – if ...

A magnetometer is a device that measures magnetism: the direction, strength, or relative change of a magnetic field at a ...

A compass needle is essentially a thin bar magnet. If it were free to move in all three dimensions, a magnet would line up along any local magnetic field line. Field lines are graphical ...

Quick – can you tell where north is? Animals as diverse as sea turtles, birds, worms, butterflies and wolves can, thanks to sensing Earth’s magnetic field. But the magnet-sensing structures inside ...