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Martin Elbin asked:
Why dont magnets ever "run out of power" to attract or repel? ferromagnets in specific, i understand why electric current magnets keep working as long as there is a current, but alignment in ferromagnets dont use current, so why do they keep working...isnt this a contradiction to entropy?
Dave - Okay. In order to create a magnet, you’ve actually got to put some energy in. Certainly, a permanent magnet. You've got to rotate all the low atomic magnets inside the piece of metal, piece of iron and rotate them all up and line them all up so their magnetic fields all add together. And that takes some energy and a magnet does have some energy. But for that to keep on going doesn’t require any energy. It’s a bit like saying, “Why does the earth keep attracting us forever?” They're just forces which exist forever. The actual magnetism in a piece of iron or in a permanent magnet is actually caused essentially by electrons orbiting in one direction more than the other, and the electrons are going to keep on orbiting, as far as we know, for billions of years, as far as we know forever, unless something interrupts them. So the little atomic magnet is going to carry on forever. There’s no reason why the magnet shouldn’t carry on.
Chris - It’s basically not burning off any energy to make the field and it’s something interacting with the field that actually makes an effect rather than the other way around.
Diana - But why is it then that some magnets get demagnetised over time?
Dave - Okay. The atomic magnets would stay magnetised, but especially if you drop them, you can cause them to re-align a bit every time you drop them. If they get very hot, they can get re-aligned as well. So, the atomic magnets is still there, but instead of all pointing the same direction, they start to become more and more randomly organised, so the overall field is less and less, and less.
martin elbin asked the Naked Scientists: why dont magnets ever "run out of power" to attract or repel? ferromagnets in specific, i understand why electric current magnets keep working as long as there is a current, but alignment in ferromagnets dont use current, so why do they keep working...isnt this a contradiction to entropy? What do you think? martin elbin , Fri, 1st Oct 2010
From the bonded ordered structure of the unpaired electron magnetic fields in the atoms. Using a magnet to create forces that stresses the bonds that enable the fields and so can weaken a magnet this is why horseshoe magnets have keepers and bar magnets are usually stored in pairs stuck together. Soul Surfer, Fri, 1st Oct 2010
To create a permanent magnet energy must be supplied to suitable materiel by immersing it in a magnetic field normally supplied by an electromagnet syhprum, Fri, 1st Oct 2010
I don't think magnets actually "store" power, nor do they consume power when they are attracting ferrous objects.
Permanent magnets do in fact store some energy, place the magnet within a coil and connect a load to it, if you cause the magnet to demagnetize by some means the collapsing field induces a current in the coil and power flows into the load. syhprum, Fri, 1st Oct 2010
Magnets are not consuming energy; the spin of the electrons within the substance of the magnet creates a field around the magnet, similar in some ways to the Earth's gravitational field that arises because the planet has mass. In both cases, an object placed within that field can interact with it, such as a stone taken to the top of a building - it has gravitational potential energy, but the energy had to be supplied by the stone being carried up in the first place. Similarly, a magnet creates a magnetic hill down which ferromagnetic materials can fall.
The LHC magnets store 3.056 MW hours of energy quite a lot to get loose if the refrigeration were to fail. syhprum, Sat, 2nd Oct 2010
I think the real thrust of Martin's question might be more along the lines of
Entropy concerns the flow of energy to maintan a force entails no flow of energy unless movement is produced.
Domain theory is what we were taught. But it fails to explain were the magnetic dark force comes from. Is it a property of the spare spaces in the outer electron shell do you think? Can you prove or disprove it??
When considering questions like this it is very important to remember that all materials are very dynamic and contain energy over and above the mass energy of the particles that make them up. let me describe them in ascending order of magnitude
Maybe this one might shed some light on it? Magnets and fractals.
To get an idea at what I'm aiming at here you can research Mitchell J. Feigenbaum. and his Feigenbaum Constant.
There's not a lot of dispute that magnetic materials are somehow drawn towards each other. Is this because of an attractive force, or is it due to the absence of some repulsive force?
Well, that seems to have pretty much put the kibosh on this thread Geezer, Thu, 7th Oct 2010
You done killed it.
I think JP has already confirmed my hunch that the force is mediated by virtual photons. syhprum, Fri, 8th Oct 2010
Bungee cords would also use virtual photons to transmit the forces between their atoms.
Part of it's the "shut-up-and-calculate" nature of quantum mechanics. It's weird, not necessarily intuitive, but it gets incredibly accurate results.
This is getting off-topic, but in some sense getting virtual particles out of quantum fields is a lot like getting classical mechanics out of the quantum mechanical waves of matter. The motion of matter is technically described in QM by a nasty integral expression involving all possible paths the object could take. However, if the object is large enough, the most important contribution to this expression is the one described by classical mechanics. jpetruccelli, Fri, 8th Oct 2010
I think QM is a bit like miracles to religious believers, if you believe in an Omnipotent being that can make anything happen the world becomes very simple you just say it happens that way because god wills it.
I think they can explain it. It's just that the explanation and solution often requires very complicated expressions, and isn't all that enlightening: It's just treating the fields with quantum mechanics, which means you end up with a lot of quantum mechanical wave integrals. There happens to be a good approximation that can be made and that approximation happens to have a nice(r) interpretation as something that's particle-like.
I think it has to do with our natural limitations. It's impressive that we are starting to create words and ideas describing things we can't observe, but that we expect to be 'there' anyway. Our universe is changing into a concept where its origin becomes something not 'existing' to us, creating what we see as the 'reality'.
I must confess that I do not understand how a magnet works. Could it be a form of natural storage of electricity? Thanks for comments. Joe L. Ogan Joe L. Ogan, Sun, 5th Dec 2010
You could see it one of two ways Joe, or more? Who knows :) Either as 'forces' forcing 'transitions', or as 'emergences' creating 'new properties'. The second viewpoint gathers under chaos theory.
The important thing to understand there is that the 'relations' is 'SpaceTime', no 'background' needed to it. Also creating the idea we have of 'discrete events' when passing a certain 'size'. That makes us like some 'foam' on, or in, a ocean of 'something else'. And it also allows for what what we call 'forces' to be created, without what we call the 'arrow of time' involved, on that 'plane below/inside/outside' whatever :) that may exist.
Hi, yor_on. Now that really clears everything up. If I could get someone to explain what you said, I am sure that I would understand it even better. LOL Thanks for comments. Joe L. Ogan Joe L. Ogan, Sun, 5th Dec 2010
Heh, you might be right Joe :) yor_on, Mon, 6th Dec 2010
You could look at this way, maybe :), from my point of view.
I'm afraid that, despite my PhD including a certain amount of work on "magnetic materials", I can't offer any great insights or explanations (especially not now, 10 years on).
Ok, here is what I've gleaned....
Very nice thedoc. Solid matter physics sort of, like we had different densities where 'matter' had one, 'virtual particles' another. Those densities observable as unchanging for us gaining different kind of 'properties', defined by the 'densities' we can't observe. I like that. yor_on, Fri, 31st Dec 2010
I n my opinion it is likely a yet to be fully understood relationship to the electromagnetic for carrier photons.. Conservation of energy must apply if a magnet does work lifting an iron filling off a table it may weaken yet over time and a constant temperature and pressure it should gain from background photon bombardment the energy necessary to replenish less loss due to Entropy it steady state values. Recall; we are not taking about electron orbital promotion but rather effects that would affect things spectral broadening and possibly generalized positional uncertainty as well as internal momentum uncertainties.To get an analogous insight into these notions study Mass-Spectrometry. This is my opinion - I do not have PhD. Tom, Mon, 9th Nov 2015
Dave definition isn't accurate at all,the mechanisms of magnetism are still a mystery,he did not address the question.physicist admit that we don't know why magnets work ,we only know that they do and it has to do with an unbalance of electrons.you should Google it yourself. Dre314, Tue, 13th Sep 2016