ferromagnetism

Copper sulfide does a lot of weird things, and it's very easy to screw with ferromagnetism in unexpected ways.

If the video showed ferromagnetism, which parts of the material and/or impurities are ferromagnetic enough for that to happen?

By connecting ferromagnetism to circulating currents (i.e, paramagnetism and diamagnetism), you just repeated the same mistake.

With this narrower sense, there is still no need to use quantum mechanics to explain ferromagnetism.

To the parent and its sibling comments: There is no atomic or subatomic current that can explain ferromagnetism in any approximation.

The Feynman lecture you linked to is an explanation why currents fail to explain ferromagnetism.

With that and them presenting ferromagnetism as the Messner effect makes me kind of question the competence of the entire analysis.

Our results pave the way for developing quantum coherent devices, including qubits and sensors, that utilize the interplay between ferromagnetism and superconductivity.

The same would not happen with a printed, non-magnetic gun (if we put aside the bullet's ferromagnetism, if any..).

The Ising spin model of ferromagnetism is another reversible cellular automata technique.

Can we apply Ising models used to explain ferromagnetism to how opinions get formed in crowds?

In the context of the article it's probably ferromagnetism and antiferromagnetism though.

Most of the things we call "magnets" exhibit ferromagnetism, which typically produces much stronger forces than either of the previous two.

You said, > Ferromagnetism has nothing to do with currents This is why I said ferromagnetism is circulating current in the sense of "to a first approximation" and "heuristically".

Because it means the entire disagreement is entirely down to what kinds of "metal images" are acceptable, rather than any factual, like "whether a full quantum treatment of ferromagnetism is necessary to completely explain ferromagnetism (of course it is)." The rest of us who don't solve research problems believe a toy model is still interesting, but don't deny (nor mention) better models.

Once you accept that physics absolutely allows the creation of a static magnetic field from a circulating current that flows forever in a zero-resistance inductor coil, then the existence of ferromagnetism is no stranger than that - to a first approximation, it also comes from circulating currents, "just" on a subatomic scale.

Ferromagnetism has nothing to do with currents, it is due to aligned spins of partially filled shells.

Ferromagnetism does both, attracts and repels, but only certain materials are ferromagnetic.