The HIDDEN Magnets in Your Phone ft. MKBHD

If you take a strong magnet you can wipe a refrigerator magnet so all the north (or south) fields point towards the refrigerator and it will no longer stick to a refrigerator. You can restore it by using a ruler and place it over the refrigerator magnet so it only covers the edge. Run the strong magnet over the refrigerator magnet using the ruler as a guide. Then move the ruler a few mm inwards, flip the strong magnet, and repeat. Keep doing this and you will restore the alternating fields on the refrigerator magnet and it will again stick to the refrigerator.