compass needle

"Each electron possesses a magnetic spin that acts like a tiny compass needle embedded in the material, reacting to the local magnetic field," said Rice materials scientist and co-author Boris Yakobson.

Jones held the dripping candle over the protective glass cover that shielded the dancing compass needle, showing Booth the course to steer.

Above, the mast tilted back and forth like a compass needle aimed at the sky.

When ancient ceramics or mud bricks that contain ferromagnetic, or certain iron-bearing, minerals are heated to sufficiently high temperatures, the magnetic moments of the minerals behave like a compass needle, reflecting the orientation and intensity of the field at the time of burning.

These errors are akin to flipping a compass needle from north to south or east to west, respectively.