🧲 Magnets

Updated at 2022-10-09 20:00

Every magnet has a north and a south pole. North pole attract south poles and via versa.

The magnetic field lines always run from the north pole to the south pole.

Don't think magnet as having a positive and a negative side. It will just confuse future yourself and everybody else.

And don't use + and - as signs for the poles. Prefer N and S.

Your magnet's north pole is attracted to the Earth's north pole. Technically, the Earth is labeled backwards. The magnetic pole near the geographic north pole is actually the magnetic south pole of the huge magnet we call Earth. It is slightly confusing, but makes orienting your magnets with a compass more logical.

If you place a magnet near a compass, the compass north arrow points to the south pole of the magnet.

Magnetic north pole is painted red by convention; if the poles are painted. South pole is made blue, green or unpainted.

Permanent magnets have a natural lifespan. But most permanent magnets will retain their magnetism for decades, usually much longer.

neodymium magnet naturally loses half its strength over 500 years

You can accidentally weaken permanent magnets by:

  • heating the magnet over 80 °C for a prolonged period
  • force a pole near the same pole of another magnetic field for a prolonged period
  • dropping the magnet a lot

But all of these weaken the magnet only very very very slightly.

Storing magnets:

  • Keep the magnets in the vendor-supplied packaging.
  • Keep the magnets in a row so the rows are attracting.
  • Keep the magnets attached to a thing they attach to like steel.
  • Keep packages of unlike magnets separated.