and where they can attract or repel other magnets. Although we cannot see magnetic field lines, we can detect them using iron filings. The tiny pieces of iron line up in a magnetic field.

If these metals have not been turned into a permanent magnet they will still be attracted to a magnet if placed within a magnetic field ... Magnetic fields lines are invisible but they fill ...

Earth's magnetic field occasionally bursts into song — but these compositions are written with electromagnetic radiation, not ...