MAGNETS: How Do They Work?

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Recommends Paulo Buchsbaum · 2013-10 · Physics Stack Exchange · on “Why magnetic field lines and force are not orthogonal with magnets?”

The below explanation why magnetism exists is superb in this video [LINK] . The explanation about magnets is also great in this video [this video] . A magnet has atoms with unpaired electrons forming mini magnets. The crystals in the magnet align the atoms in the same direction. If you use a magnet you can align permanently the atoms in some iron ores (e.g. ferrite). The plane of moving charges inside the magnet has many directions, that are approximately in the plane and perpendicular to the magnetic field lines. The magnet attracts or repels other magnet, with the same type of moving charges. [Edit: image [LINK] no longer available.] I have a big question about this. Imagine a moving charge pas

Recommends Yashbhatt · 2014-05 · Physics Stack Exchange · on “Which magnet will last longer?”

See this [this video] . It explains very simply how electrons have to align their intrinsic magnetic momentum and how magnetic fields of electrons cancel out if the shell is full etc. In short all the factors which determine the magnetism of a permanent magnet.

Recommends Thaina · 2014-10 · Physics Stack Exchange · on “Why in a solenoid, do the magnetic field lines resemble that of a bar magnet?”

Opposite. Solenoid is actually like real magnet bar Imagine one iron atom. It has electrons run in circle around that atom so it generate magnetic force. Every iron atom is like a solenoid loop by itself Then Imagine a bar magnet is clump of iron which almost all atoms align in the same direction so every atom contribute a magnetic force. That's it much more like many solenoid loops parallel to each other In detail you should watch this video [this video]

Recommends Jaywalker · 2017-05 · Physics Stack Exchange · on “Permanent magnets and quantum spin”

A lot of atoms by themselves are magnetic dipoles because of the electron configuration in their valence shell. However this does not mean that they are all ferromagnetic like iron. Iron and other elements like it only tend to exhibit magnetic properties because of their crystal structures and the alignment of the domains within the material. Liquids and gases do not tend to exhibit this behavior because their atoms are not fixed in a highly ordered lattice like in solid iron. While magnetic effects can be observed for molten or gaseous elements they are usually due to electromagnetic induction. For the case of the earth's core for example it is suspected that there is self-sustaining feedba

Recommends StephenG - Help Ukraine · 2017-06 · Physics Stack Exchange · on “How does a force get transmitted when a magnet attracts iron?”

According to particle physics , every fundamental force has its force carrier particle. Photon is a force carrier particle of electromagnetic force but how does force gets transmitted when a iron is brought near magnet quantum mechanically ? The detailed mechanism is described by the very complex Quantum ElectroDynamics [LINK] theory (QED for short). Now I looked for a relatively simple explanation or overview of this and found nothing I liked (or feel you'd be happy with). However I did find this very short segment of an interview with Richard Feynman (who was one of the key developers of QED) about this question and why it's so very difficult to explain to a non-expert [LINK] . It's worth

Recommends Martin J · 2018-03 · Physics Stack Exchange · on “Does special relativity explains working of an electromagnet?”

I got caught up trying to find the answer to this question after watching the Veritasium [LINK] and MinutePhysics [this video] videos mentioned in other answers. I would highly recommend watching them as they get the big picture and have some nice visuals. There is some debate in these forums regarding the accuracy of the videos' explanation, but after going through the video, its sources, and the criticism, I still believe the argument is valid. This post is based largely on the videos, and also checking the video's reference Purcell [LINK] (2nd ed. pp 178-181 & 192-199), and the Feynman lectures 13-6 [LINK] for good measure. See either of these for more details. Similar discussions that are wor

Recommends Phil Frost · 2018-06 · Physics Stack Exchange · on “Can a magnetic field exist without an electric field present?”

The "magnetic field" is a concept within classical electrodynamics. Maxwell's equations were developed in the mid 19th century at a time where basic atomic physics was still a nascent field of study. Viewed in the contemporary historical context, a permanent magnet is a perfectly fine example of a magnetic field without an electric field. Within the theory of classical electrodynamics, there is no explanation for why the magnetic field exists, only that it does exist, and how it's related to the electric field. Permanent magnets have a magnetic field as an intrinsic, fundamental property, similar to the reasons rocks have mass. They just do. In the past one and a half centuries other theorie

Recommends mmesser314 · 2021-08 · Physics Stack Exchange · on “Why are neodymium magnets ground into powder rather than cast?”

First watch MAGNETS: How Do They Work? [this video] by MinutePhysics and Veritasium. It is a good explanation, but one point we care about was simplified away. Magnetic domains are tied to crystal structure. Crystal structure creates easy directions. For example, an iron crystal has either a body centered cubic or face centered cubic structure. Each atom has nearest neighbors in various different directions. Nearest neighbor atoms tend to align N pole to S pole, like bar magnets. This can happen in any of the nearest neighbor directions. These are called "easy" directions because it is easy to magnetize an iron crystal in these directions. [LINK] Image from [LINK] Typically iron is made out of ma

Recommends RC_23 · 2021-10 · Physics Stack Exchange · on “Are all of the aligned spins in a ferromagnet pointing in the same direction? Or does the 'south pole' consist of electrons pointing oppositely?”

They are only opposite in an anti-ferromagnetic material, so no. I think all your questions stem from a misunderstanding of magnetic dipole. Every single individual electron has a magnetic field with both a North and South pole. And yes, only valence electrons are involved, since filled shells have even numbers of electrons all with equal numbers pointing in opposite directions. Thus they cannot contribute to a magnetic domain. I would suggest watching this video [this video]

Recommends mmesser314 · 2023-04 · Physics Stack Exchange · on “What is the secret behind the striking similarity between a quark pair and a bar magnet?”

Under the hood, it isn't as similar as it looks. For background on quarks, see these Veritasium videos: Empty Space is NOT Empty [LINK] and Your Mass is NOT From the Higgs Boson [LINK] As these say, if you try to separate a quark/antiquark pair, you have to add so much energy that you create another quark/antiquark pair. You wind up with two pairs, neither of which is separated. For background on magents, see the Veritasium/MinutePhysics video MAGNETS: How Do They Work? [this video] As this explains, there are no N and S particles that could be separated. Even at the level of a single particle, the particle itself is a tiny magnet with a N and S end. A bar magnet contains a lot of these lined up.