It’s a bit like gravity. We have some good theories, but that’s about it.
No! That’s the point I’m trying to make! Gravity and its source truly are a mystery (aside from the basic fact that it causes mass to attract other mass, of course)
Magnetism is a well defined component of the electromagnetic force. We know what it is, where it comes from, and why it has the effect that it does. We’ve known most of this for a century! The study of electromagnetism came early to the field of physics because it’s easy to work with and understand on human scales.
To be very short, moving electricity creates magnetism; moving magnetism creates electricity. A permanent magnet is magnetic because most of the electrons are spinning the same way, creating magnetism. That’s it.
That is what you tell the grade 4 students.
Later you can teach them about magnetic domains, dipole moment, electric and magnetic fields and their relationship to radio waves etc… But these are all things we know, and I feel like it’s important that kids know that humanity has in fact mastered magnetism.
Sure there is still a lot to learn, but at this point it’s engineering, not science. Practical things like magnetic alloys or optimal field arrangements for motors.
I_Has_A_Hat@startrek.website 11 months ago
Isn’t it the alignment of molecules in a material so that their electrical charges are all oriented in the same direction, thus attracting the opposite charged ions of other molecules in other objects towards the corresponding side of the magnet material? That’s why magnetism only affects materials like iron where the molecules naturally form in a uniform orientation during it’s transition from solid to liquid, and not other material that has a more random orientation.
I mean, I guess when you really boil it down, there may still be some question as to why positively charged ions are attracted to negatively charged ions in the first place. But then we’re getting into quantum mechanics which is way deeper of an answer than a grade schooler would be looking for and so far down the rabbit hole that making a claim like “we dont know how magnets work” is only true in the technical sense. And by that, I mean it holds as much truth as “we don’t know how anything works”.