Talk:Magnetism

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Error in magnetic domains image[edit]

I remember my previous physics teacher said that this image: http://en.wikipedia.org/wiki/File:Ferromag_Matl_Magnetized.JPG in the Magnetic domains section is wrong. The arrows should go from north to south. I never really understood his argument so I'm just asking that somebody with more knowledge in this subject take a look at it.

Antonio92 (talk) 08:31, 21 June 2012 (UTC)

Confirmed: Outside a magnet the lines definitely go north to south. (Inside the B field goes S-->N, the H field goes N-->S.) I corrected the image. (It sometimes takes a day or two before the up-to-date image thumbnail gets put on the page.) --Steve (talk) 14:30, 21 June 2012 (UTC)Subzbharti (talk) 18:13, 21 March 2013 (UTC)

Problem with figure[edit]

Hierarchy of types of magnetism.[7]caption in the diagram are blurred and not readable. Please edit them suitably. thanks — Preceding unsigned comment added by Subzbharti (talkcontribs) 18:13, 21 March 2013

Lead[edit]

I know how hard it is to write the introductory sections for topics like this, and how it tends to generate endless edit wars over minor wording differences. I don't mean to criticize the hard work that has been done on this article. But I feel I don't understand the lead sentence:

Magnetism is a class of physical phenomena that includes forces exerted by magnets on other magnets.

Doesn't magnetism also include forces exerted by magnets on materials which are not magnets? And I'm wondering if the term magnetic field should be introduced earlier, in the first sentence, instead of the 3rd. --ChetvornoTALK 23:32, 19 September 2014 (UTC)

I've tweaked it, hopefully addressing your immediate concern (I agree that it was probelmatic); see what you think. —Quondum 00:09, 20 September 2014 (UTC)
That looks a lot better to me. I like the lead sentence, it a good definition. --ChetvornoTALK 00:27, 20 September 2014 (UTC)

Unified Field Theory and Magnetism[edit]

We adventure into UFT by assuming there is but one source of forces, and that all forces can be explained by characteristics of a space with nothing but relative levels of compression. This means the concept of electromagnetic charge as a characteristic of particles is forbidden.

Mass acquires the definition of an expansion of space, compressing space around it. (Hence it is relative like spacial measurements, and hence it is energy.)

This definition reconciles the strong and nuclear forces rather easily. Two particles of mass that get too close push each other away encompassing the strong nuclear force. The sphere packing of an atomic nucleus, or a star containing black holes, creates suction between its component particles and towards its interior as it expands, encompassing the weak nuclear force. The misshapenness of the compressed space is responsible for gravity. But what is magnetism?

What is magnetism? Why do the same poles of magnets repel and opposites attract? Well, if you spin a massive particle about an orbit you generate a corkscrew shaped object in space time. As two magnetic poles opposite in polarity approach their spin is in the same direction which reduces antagonism from the expanding objects. Conversely, if two magnetic poles identical in polarity approach, their direction is opposite and they plow into each other increasing expansive antagonism.

Magnets, whether the planet earth, a bar magnet, an electromagnet, a gyroscope, all generate their fields through the rotation of mass in the same direction with some preponderance. — Preceding unsigned comment added by GuildCompounder (talkcontribs) 00:19, 1 April 2015 (UTC)

Sources of magnetism[edit]

The section on Sources of magnetism describes two sources - current and the nuclear moment - before launching into a discussion of the electron magnetic moment. No connection is explained between the list of sources and the subsequent discussion. Can this be added? 83.104.46.71 (talk) 08:59, 10 May 2015 (UTC)

I agree; the electron magnetic moment seems to be inexplicably lumped in with electric current. I think the second bullet point, nuclear dipole moment, should be expanded to include all particle dipole moments. --ChetvornoTALK 09:31, 10 May 2015 (UTC)
Me three. The magnetic moment associated with the orbital angular momentum of an electron should presumably also be included in the second point. But perhaps we should not be trying to classify the sources so distinctly into two categories; rather it might be better to simply list several contributors: electric current (flow of electrons, ions and any charge-carrying particles generally), intrinsic spin of elementary particles, orbital contributions. Technically, nuclear magnetic moment arises from a combination of the last two of its constituent particles. —Quondum 16:28, 10 May 2015 (UTC)
I can see that point of view, but my feeling is it would better to limit the bullet points to the fundamental sources, currents and intrinsic spin. Orbital magnetic moment can be understood as a circular "current" of charge about the nucleus. This can be explained in the following text. Explaining it that way would give entry-level readers a more intuitive understanding: charge + motion = magnetic field --ChetvornoTALK 17:45, 10 May 2015 (UTC)
That might not be so rigorous. It works as an intuitive explanation. However, I expect that the magnetic moment due to intrinsic spin of a particle falls into the same explanation (rotary current), and is indistinguishable at a mathematical level. I don't think that it is for us to be making such hazy, ill-defined distinctions. —Quondum 18:47, 10 May 2015 (UTC)
Kittel lists the principal sources in a free atom as electron spin, electron orbital angular momentum, and the change in angular momentum induced by an applied field. The first two give rise to paramagnetism and the third to diamagnetism. This satisfies the desire of the IP editor for a connection between sources and phenomena. Note the focus on a free atom, with ordered arrays of moments to be discussed separately in connection with phenomena like ferromagnetism. Similarly, electron currents as sources primarily arise in connection with electromagnets. Nuclear magnetic moments are 1000 times smaller than electron magnetic moments, so they should not be listed as principal sources. RockMagnetist(talk) 03:44, 11 May 2015 (UTC)