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/sci/ - Science & Math

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5025770 No.5025770 [Reply] [Original]

Hi /sci/
I'm a bit slow. Well I feel that way because my question I have.
I want to know how magnets work. I looked it up. I repeatedly got magnets are surrounded by magnet fields etc.
I just want answers to 1) what material makes a magnet? 2) how are they made? 3) How do they work?

>> No.5025779

Physics Guy spent some time to write this out

The "magnetic field" is a special relativistic effect of the electric field. There is basically one one field the "Electromagnetic field", but depending on how you view it, you will either see it as an electric field, magnetic field, or a combination of both.

All atoms contain moving electrons, each with spin. The movement (apparent movement) and spin each produce a small magnetic moment (think of a magnetic arrow). These arrows can align themselves anti-parallel to cancel any net magnetism, or parrallel to show a net magnetism, or a ton of other crazy senarios!

All materials can be magnetized (at a certain tempertaures that allows for the tiny arrows to move in a parallel configuration) by introducing a external magnetic field. When the field is removed, the arrows realign (relax), this could take seconds or centuries. Permanent magnets are the kind that take centuries for there arrows to relax back into so random configuration.

continued...

>> No.5025784

>>5025779
The common magnets we use (including the ones you mention ) have d-shell (or f-shell in case of rare earth magnets) electrons incompletely filled, hence a net non-zero spin. The configuration of the bulk materials of these atoms is such that it allows for the arrows to move at room temperature (energetically favorable). They then have a huge relaxation time (bulk material property), hence it takes them centuries to loose there magnetism naturally. Now, the question becomes how will these materials align in the external field. Well for the ones you mention it is energetically favored for them to align parallel to the external field (hence they will have a net magnetism). For the rest of the atoms with incomplete orbitals (that have movable arrows at room temperature) they align anti-parrallel.

The determination of the bulk material properties of a substance form first principles in not trivial. It requires alot of material science, chemistry, and quantum mechanics. Often these calculations are so tedious that they do them on super-computers. This is still an area of active research, and there is no easy way to determine all the bulk properties of any random material. We lack the computer power....

>> No.5025785

Changing electric fields cause a magnetic field.

>> No.5025793

>>5025784
>>5025779
thank you for your thorough explanation!
I was with some friends the other night, and a guy made fun of the ICP line of "Magnets, how do they work" then I realized I wasn't entirely sure. Thanks again

>> No.5025831

>>5025793
the ICP line really is kinda true.

fucking magnets. it's one of the hardest physics concepts to grasp.

>> No.5026402

>>5025831

and, in spite of all the ridicule ICP got, NOBODY KNOWS how magnets work, at least with respect to the magnetic force. it's just one of the fundamental forces, and as such, it DOES appear to be somewhat magical.

i'm not a juggalo, btw.

>> No.5026406

>thread about magnets

I want a magnetic gas, get to work guys.

>> No.5026439

>>5026406

Can't do it bro, didn't you read the thread? Gas can diffuse freely, so it'll never be magnetic on its own. Same for fluids that aren't suspensions of solids.