I have an old baby rattle that consists of six small balls inside a larger clear sphere. When at rest, the balls repel each other, and never touch. Assuming they are magnets, shouldn’t they immediately clump together?
Video: [https://www.reddit.com/user/PM_ME_YR_BOOPS/comments/gwammg/baby_rattle_with_magnets_that_only_repel/](https://www.reddit.com/user/PM_ME_YR_BOOPS/comments/gwammg/baby_rattle_with_magnets_that_only_repel/)
In: Physics
I believe the balls aren’t magnetic, they are electrets. They retain a static electric charge that is uniform within them. The balls are held apart by the ensuing electrostatic forces. This is the same effect makes plastic cling wrap work.
You can test this theory by bringing another statically charged object near them, like a balloon rubbed on hair. If the balls are electrets, they should be attracted/repelled away from the balloon.
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