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Mr_Holes
2009-Jul-04, 06:58 PM
Hello everybody,

I have a question again.

There exists superconductivity of electrical current.

There exists superconductivity of thermal energy with superfluids like helium 3 and helium 4.

There exists no viscosity with superfluids.

I would like to know if a state where perfect conducting of magnetic field lines is also possible ?

korjik
2009-Jul-04, 07:21 PM
Magnetic field lines dont conduct.

The question dosent really make sense tho. Electrical superconductivity is current flow with zero resistance. Thermal superconductivity is heat flow with zero resistance. Superfluidity is fluid flow with zero resistance.

Magnetic fields dont flow.

Mr_Holes
2009-Jul-04, 09:00 PM
Magnetic field lines dont conduct.

The question dosent really make sense tho. Electrical superconductivity is current flow with zero resistance. Thermal superconductivity is heat flow with zero resistance. Superfluidity is fluid flow with zero resistance.

Magnetic fields dont flow.

I understand what you mean, but here is i what i was thinking.

There is electric current and there is a electric field.

There is super fluidity and there is a force.
I mean to say when you have resistance you have to build up a counterforce.
You could say there is a force difference.

There is thermal conductivity and there is thermal isolation.
You could say that there is a thermal field because of the thermal difference.

There is .... and there is a magnetic field.

I know there is nothing more then magnetic field lines but is that not odd.
Should there also not be an magnetic counterpart other then just a force ? Should there not be an magnetic flow possible as well ?

tashirosgt
2009-Jul-05, 01:22 AM
.

Electric current is a flow of a scalar quantity, "charge".
Fluid flow is a flow of a scalar quantity, "mass".
Heat flow is a flow of a scalar quanity, "heat".

What would "magnetic flow" be a flow of? A scalar quantity "north"? You would need magnetic monopoles. The question is why imagining a magnetic field to be constructed of magnetic monopoles doesn't work well.

Flows have conservation laws. If the flow into a region doesn't match the flow out, then there is a build-up of something in the region (charge, mass, heat). It would be hard to build up "north"-ness somewhere without "south"-ness building up somewhere else. How do you capture that with mathematics?

Mr_Holes
2009-Jul-05, 02:01 AM
.

Electric current is a flow of a scalar quantity, "charge".
Fluid flow is a flow of a scalar quantity, "mass".
Heat flow is a flow of a scalar quanity, "heat".

What would "magnetic flow" be a flow of? A scalar quantity "north"? You would need magnetic monopoles. The question is why imagining a magnetic field to be constructed of magnetic monopoles doesn't work well.

Flows have conservation laws. If the flow into a region doesn't match the flow out, then there is a build-up of something in the region (charge, mass, heat). It would be hard to build up "north"-ness somewhere without "south"-ness building up somewhere else. How do you capture that with mathematics?


Well maybe when the magnetic field builds up between a north and a south poles there is a flow ? I think it is like a capacitor, when the charge between the plates is not equal as the external applied voltage current will flow untill the capacitor has the same voltage. I guess something similair would happen with a magnet as well.
But how fast would this build up be. I am assuming when i would take an electromagnet and power it up with a dc power supply the build up of the magnetic field follows the current flowing through the electromagnet untill all field lines penetrate the core of the electromagnet if i am not mistaken. But how would this function in a vacuum ? I really do not know. Does a magnetic field in a vacuum also build up with the speed of light ? I find magnetic field lines curious. And how does this all relate to a permanent magnet ?

korjik
2009-Jul-05, 08:30 AM
I understand what you mean, but here is i what i was thinking.

There is electric current and there is a electric field.

There is super fluidity and there is a force.
I mean to say when you have resistance you have to build up a counterforce.
You could say there is a force difference.

There is thermal conductivity and there is thermal isolation.
You could say that there is a thermal field because of the thermal difference.

There is .... and there is a magnetic field.

I know there is nothing more then magnetic field lines but is that not odd.
Should there also not be an magnetic counterpart other then just a force ? Should there not be an magnetic flow possible as well ?

Where there is charge there is an electric field
Where there is current there is a magnetic field.

this is most of the reason why it is called electromagnetism now, instead of seperate electricity and magnetism.

mugaliens
2009-Jul-06, 09:23 AM
Should there also not be an magnetic counterpart other then just a force ? Should there not be an magnetic flow possible as well ?

Gravity doesn't flow. It's a tensor. Magnetism doesn't flow. It's a tensor.

robross
2009-Jul-06, 10:08 AM
.

What would "magnetic flow" be a flow of? A scalar quantity "north"? You would need magnetic monopoles. The question is why imagining a magnetic field to be constructed of magnetic monopoles doesn't work well.


I've always been confused about how a magnetic monopole would actually be constructed. I know they're theoretical, but some people do believe they exist...someplace else, or in the early universe.

But how would you structure matter to create such a thing? Has anyone designed any models of how atoms could arrange themselves to only have a single pole? I don't have a conception of how this could actually work in nature.

Rob

cjameshuff
2009-Jul-06, 01:49 PM
But how would you structure matter to create such a thing? Has anyone designed any models of how atoms could arrange themselves to only have a single pole? I don't have a conception of how this could actually work in nature.

Er, you don't...magnetic monopoles wouldn't be made out of atoms. If they exist or can be created, they would be elementary particles, like electrons.

Mr_Holes
2009-Jul-12, 12:10 PM
Where there is charge there is an electric field
Where there is current there is a magnetic field.

this is most of the reason why it is called electromagnetism now, instead of seperate electricity and magnetism.


i understand that. But in a perfect vacuum there can also be an electromagnetic field. There is no current flow then i would think.