(forgive me any grammatical flaws, english is not my native language)
i know that according to Earnshaw's theorem a stable levitation cannot exist by only using permanent magnets.
Similar questions has been already answered (e.g) Can I levitate an object without using an electromagnet? but they don't state what actually would happen and why.
...with a setup like that for exampe.
We asume that we have a cup and a sphere. Since a perfect equilibrium cannot exists, what happens actually then?
- no levitation (no repulsive force) at all due to negation
- "instable levitation" (sphere jitters and spins)
- the sphere either sticks to the cup or pops out of it depending on it's weight