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Author Topic: Magnetism !!..what is it ?  (Read 4530 times)

Offline neilep

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Magnetism !!..what is it ?
« on: 10/09/2007 22:08:23 »
When I hold two magnets together , depending on the orientation, they either pull together or push themselves apart !!

So, what is it ?...Is Magnetism ' stuff ' ?...the reason I ask that is because there is s definite force acting upon the magnets.....but I can't see it...and I can only feel it with another magnet !....even I'm not that attractive !! (hard to believe I know !)


Offline Mr Andrew

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Magnetism !!..what is it ?
« Reply #1 on: 10/09/2007 22:18:23 »
That's a good question.  It's like asking what gravity's a force that acts on two masses (there can be things with no mass like things can have no charge).  Einstein solved the gravity problem but no one has come up with a good explaination of electricity or magnetism yet.  Maxwell's equations just describe them, but they don't explain them.


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Magnetism !!..what is it ?
« Reply #2 on: 10/09/2007 23:22:05 »
Some things just can't be 'explained' using the ideas we all know and love.
People have tried to  explain things like magnetism - waste of time.
It's just something that happens and it follows certain rules, within certain limits.
You can predict the force between two wires carrying electric current and you can base your prediction on ideas like 'fields' or 'action at a distance'. You can take it further and further but DON'T ask for an explanation unless you want to spend your whole life on it.
What do we mean by "what do we mean by 'what do we mean by mean by mean'""?
That stuff is only for very erudite people and I have a feeling that many of them couldn't, in fact apply Maxwell's Equations to  solve a simple situation.
I have to agree that the force between two strong magnets is totally impressive and totally baffling - because it's not something we are used to . It's stronger than what we are accustomed to.  The force from an electric motor is just not impressive - we are too familiar with it.
Why are we not just as impressed when we lift a lump of lead? That's a stronger force than normal - but it's not enough to impress us.
However - I was once given a fresh (not radioactively hot) fuel rod for a Magnox Reactor to hold. That was about as thick as a broom handle with light alloy fins on it. I was TOTALLY GOBSMACKED by how heavy it was. Uranium is really really dense  and my  eyes told me that a bright shiny thing should feel like aluminium. It was over 40 years ago and I can still remember the experience. Was it magic ? No it was just gravitational attraction between a very dense rod and the Earth.


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Offline Soul Surfer

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Magnetism !!..what is it ?
« Reply #4 on: 11/09/2007 08:45:58 »
It IS possible to explain magnetism provided we accept a few givens  and the reference above showing how magnetism may be "explained" via electrostatics and gravity.

for simplicity let me recapitulate the basics.

The fact that all masses create an attractive force of gravity is easily understood and observed every day in our life here on earth although the behaviour of large groups of gas and stars moving under their mutual gravity is quite complex and not well understood by most people.  (but that's a different story for another day)

We can also observe simple electrostatic effects using the classic dry glass rods rubbed with silk and plastic rods rubbed by fur.  These can be shown to have opposite charges too  although some of the behaviour may be unexpected for technical reasons (and I will not go into that in this brief description.  so the existence of two sorts of electrical charges  that are called positive and negative where like charges repel each other and unlike charges attract  is well within home experimentation and probably to be found elsewhere on this website.

Electrostatic effects are only part of a force process called electromagnetism.  This is because  the electrical and the magnetic processes are inextricably bound up together because when electrical charges move they create magnetism. A stream of moving electrical charges of similar polarity is called an electrical current and this creates a magnetic field circulating around the stream  you could visualise this as a bit like a vortex.

The article referenced above shows how this can be described by the application of relativity to the movement of electrical charge and the force is essentially the same as that caused by static charges.

This leads to the existence of two magnetic poles and standard behaviour of electromagnets created by coils of wire carrying currents.

This description needs to be continued to explain permanent magnets and their behaviour but I have to go now and I will complete this later

Offline K.Margiani

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Magnetism !!..what is it ?
« Reply #5 on: 17/09/2007 16:21:05 »
             Magnetic Field of the Earth
   “crazy” secret of the Uranus magnetic field explained for scientists. (

   During liquid stage of the Earth development liquid nucleus was formed from liquid heavy metals' layers in the physical center. Let’s mark this volume with letter n.  The rest of the volume of the Earth was the admixture of oxides and other chemical elements fiery liquid masses. Let’s mark this volume relatively with letter m. Geoevolution of Planets at the liquid stage is characterized by the following common regularity. The rotation of liquid layers of m volume toward poles decreases little by little. The inner nucleus rotation in that stage always less then rotational speed of equatorial layer of m masses. On the liquid stage of the evolution convection streams into layers of the m masses are characterized complex turbulent movement around n nucleus. These streams with turbulent movement are moving around the inner nucleus with the direction of the planet’s rotation. At this stage almost convection streams formed summery magnetic field. By this magnetic field was created later stabile magnetic field of the solid heavy metals nucleus. On the liquid stage of evolution magnetic poles of Earth m and n masses exactly coincided with the rotation axis geographical poles. Inner nucleus is in the physical centre

     Nucleus n is characterized by the less speed of the rotation then m masses. Because of radioactive decomposition in Earth inner nucleus, huge amount of heat is of course released. This helps in the movement of m masses convection streams on this stage. Because of difference in densities, n and m masses do not mix up with each other. As a result of chemical processes, in m volumes liquid small masses of liquid metal are sediment into n volume. Liquid nucleus step by step gains more amount and volume as well.

     The formation of stable magnetic field, which exists in the inner metal nucleus nowadays, began after its hardening process. The influences of metals with paramagnetic qualities are in nucleus on this stage. They has own summary magnetic field and are very insignificant. It is caused by small percentage of those metals.  Magnetic field of metal layers with diamagnetic qualities slightly weakens the summary magnetic field ferromagnetic metals layers. It can be said that on the full liquid stage the Earth had mainly n and m masses summary magnetic field.

        During the geoevolution of planets on the first stage its inner nucleus metals layers begin to turn into solid condition. On the second stage D layer of planets becomes solid. It divides convection streams of m masses into ­­­two parts. This causes decreasing of the magnetic field of m masses convection streams. Increasing of D layer causes the enlargement of liquid layers density. By this process was decreased convection streams movement and of course came to the end magnetic field made by these streams. On the third stage planets surface begins to turn into solid condition, with formation very thing solid crust.

        Into liquid heavy metals nucleus stable dipolar magnetic field is creating during hardening stage of nucleus, only in the case, if nucleus ferromagnetic layers can record the initial magnetic field made by m masses. This is possible when temperature of solid ferromagnetic metals layers are lower, then the Curie point (under conditions of high density and colossal pressure). Parallel with the process of magnetic field weakening caused by m masses, into heavy metals solid nucleus of paramagnetic and diamagnetic metals layers magnetic field undergoes mainly influence of recorded magnetic field by the ferromagnetic metals layers.

       At last Earth’s magnetic evolution was transferred to the stage of heavy metals solid nucleus’ almost stable dipolar magnetic field. From this stage Earth’s dipolar magnetic field is made up almost by the solid metals nucleus ferromagnetic layers. Diamagnetic metals layers into inner nucleus slightly weaken the summary magnetic field of ferromagnetic metals layers.

   According to cosmogeological theory if a planet has a vivid rotation around its axis, it should have its own dipolar magnetic field. Only Mercury is an exception. Its rotation was almost prevented by the impact of big asteroid(chunk of huge geolayer). Today's rotation speed would never form dipolar magnetic field of Mercury. Influence of changeable Sun magnetic field on the Mercury’s magnetic evolution is another topic of research.

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Magnetism !!..what is it ?
« Reply #5 on: 17/09/2007 16:21:05 »


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