This means that their magnetism is there all the time and cannot be turned on or off as it can with an electromagnet. Converting a magnet to a non-magnet is called demagnetisation. Magnets are ...

and it weakens with increased distance from the magnet, creating a spatial magnetic field gradient. The distribution of the magnetic field outside of the main magnet (also called the fringe field ...

Human neuroimaging Researchers in Massachusetts are developing a human brain-scale MPI scanner with a mechanically rotated, permanent magnet-based field-free line. (Courtesy: Lawrence Wald) Magnetic ...