What is the Nature of Magnetism?

[zoobyshoe]

All right! I did it, finally. I got a whoppin' 4.9 sec fall time through a 1.5 m aluminum tube!

Congratulations!

So now we know that the visibility of the effect is highly dependent on the strength of the magnet.

-Zooby

 

[zoobyshoe]

so physicists still do not know what the magnetic field is actually made up of right ?

I think this is more or less true. It's true for almost everything, though. At a certain level they no longer know what anything is actually made up of. All they can tell you is what it does, not what it is.

 

[kuenmao]

Isn't the magnetic field just invented(YES, invented) by scientists? There is actually no such thing as a magnetic field, if you define things to be made up of some mass. It is just a construct of the human mind so as to easily see the effects of a magnetic field on the system we are talking about. If you ask what it is made of, then the best answer would be: nothing, save the imagination of the human brain.

 

[krab]

This magnet is ridiculously strong. I have no idea what it is - the mystery magnet.

My guess is that it is Samarium-Cobalt.

 

[krab]

so physicists still do not know what the magnetic field is actually made up of right ?

These sorts of questions are interesting. If you look back on these forums, you will find many similar: What is the real mechanism of gravity, of mass, of electric charge, etc. I cannot help feeling that it is a result of our conditioning whereby we have a real feel for mechanical effects, but none for other kinds of effects. I also cannot help feeling that those who ask these questions need something like microscopic mechanical devices like springs and linkages. If that's the case, they are out of luck. There are no mechanical devices operating behind the scenes. In fact, even the mechanical things we know about are fields (mostly electric) at the microscopic level. Yes, when you push your hand against something, the reason it does not go through is that there are electric fields between the atoms that keeps them together. So, in a sense, everything is fields. It's one of the things you get used to when you learn physics. Fields just are, and they have certain properties physicists know and have measured.

 

[zoobyshoe]

krab: "I cannot help feeling that it is a result of our conditioning whereby we have a real feel for mechanical effects, but none for other kinds of effects."

I think you've hit the nail on the head. That "real feel" you mention is a neurological one: our nerves and brain are able to make an extremely useful kind of sense out of mechanical forces. Not so with fields.

krab: "I also cannot help feeling that those who ask these questions need something like microscopic mechanical devices like springs and linkages."

Again: nail on the head. That is exactly what people are looking for when they ask these questions. When a person starts wondering about these things they have no other reference frame at their disposal from which to consider them. They are not at liberty, so to speak, to ask from any other standpoint: you push two repelling magnets together, your sences demand you to understand that this is a completely mechanical phenomenon. Your mind tells you: "there must be micro-springs too fine to be seen with the naked eye." or something similar.

Krab: "So, in a sense, everything is fields. It's one of the things you get used to when you learn physics. Fields just are, and they have certain properties physicists know and have measured."

Getting used to it is, I believe, dependent on a given individual acquiring enough information about fields to see that the micro-spring (or whatever) explanation just won't satisfy everything that a field can do. You have to learn a certain number of their mysterious properties before you can face the fact that fields are a thing unto themselves, that "they just are". In other words, you have to know a fair amount about how they behave in a fair amount of circumstances before you realize that "What fields are" isn't a secret that hasn't been unlocked yet in terms of micro-springs.

What fields do, is consistent and measurable, but what they are ends up not being expressible by mechanical analogy. Fields are fields.