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chound
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What causes magnetism?
Gonzolo said:Moving electric fields (charges) explains pratically all that we see in our daily lives.
Which elementary particles and how?
Gonzolo said:I see. The explanation I was aware of for permanent magnets was that they were due to the electron revolution around nuclei. It's only as good as the Bohr model and perhaps not accurate numerically. At least it allows not having to introduce spin (which, I agree, is more accurate).
ZapperZ said:Well, if that is true, then EVERYTHING would be a permanent magnet, since every material has an "electron revolution around nuclei". But the fact that we don't, and only certain types are paramagnet, ferromagnet, etc., implies that it is a lot more complicated than that. Quantum magnetism is one of the most complex and complicated many-body problem.
Zz.
reena said:Magnetism of the brain and heart:
Both brain and heart exhibit magnetism as the magnetic field in both cases is huge. Can someone venture to guess the cause and effect of this magnetic field?
Gonzolo said:Well, it could be argued that in magnets, the normals to each orbit are aligned (same z), while in all other materials, they are not (random z). Again, I don't claim this to be a sufficient explanation to a scientist, but it is one I that have seen in a (perhaps an elementary) physics textbook. I am not sure where exactly the theory fails, although it surely does at some point.
Gonzolo said:Well, it could be argued that in magnets, the normals to each orbit are aligned (same z), while in all other materials, they are not (random z). Again, I don't claim this to be a sufficient explanation to a scientist, but it is one I that have seen in a (perhaps an elementary) physics textbook. I am not sure where exactly the theory fails, although it surely does at some point.
ZapperZ said:I'm sorry, but the magnetic field of the brain and heart are HUGE? Define "huge"!
If they are THAT huge, then it doesn't explain why detecting neuron signals from the brain require some of the most sensitive, superconducting curcuit we can build today.
Zz.
reena said:I am really sorry that I am not able to find the article I read the other day which referred to the effect of microwaves on the brain. I would like to quote the numbers and I just don't have them now!
Gokul43201 said:This reminds me of a paper I read, in Nature (or Science, not sure which) some ten years ago. It was mostly about magnet design. A group in Tokyo (I think), built these giant conventional (not-superconducting, if I remember right) electromagnets fed by 4 storey tall capacitors, which make a huge transient current.
I don't remember the field strength of the magnet, but I remember a picture where a magnet held above the center of a long trough of water caused it (the water) to mound up below the magnet. Subsequently, a little copper sulphate was added to the water making it (blue, and more importantly,) diamagnetic. Now, bringing the magnet close made the liquid part under it. They called this the "Moses Effect" !
Theelectricchild said:But why is no one answering simply? : Current.
Gonzolo said:ZapperZ and Gokul43201,
I just checked again in the book in question (pre-calculus and pre-modern physics level). There are about 17 pages based on magnetism in matter based on the Bohr model of the atom. The most impressive part is that it predicts [tex]M = \frac{e}{2m}L[/tex] for the magnetic moment of a hydrogen atom, apparently the same value as a quantum theory predicts. Paramagnetism, diamagnetism and ferromagnetism are also "covered". I consider it to be an excellent introduction, as it gives very good insight into the matter (I like puns).
Gokul43201 said:... I remember a picture where a magnet held above the center of a long trough of water caused it (the water) to mound up below the magnet. Subsequently, a little copper sulphate was added to the water making it (blue, and more importantly,) diamagnetic. Now, bringing the magnet close made the liquid part under it. They called this the "Moses Effect" !
chound said:I would appreciate if someone could make it all sense for me. I can't understand a bit what you are talking about. And in my 10th grade textbook there is no mention of what causes magnetism. So please explain detailedly
The cause of magnetism is the alignment of electrons in an object. When the electrons all spin in the same direction, it creates a magnetic field.
Magnets attract or repel each other based on the direction of their magnetic fields. Opposite poles (north and south) will attract, while the same poles will repel.
Magnetic materials, such as iron and nickel, are able to retain a permanent magnetic field due to the alignment of their electrons. Non-magnetic materials, like wood or plastic, do not have this alignment and therefore do not create a magnetic field.
Yes, temperature can affect magnetism. When heated, the electrons in a material may become more agitated and disrupt the alignment of the electrons, reducing the strength of the magnetic field.
Magnetism has many practical applications in everyday life, such as in compasses, electric motors, and credit cards. It is also used in medical imaging technology, like MRI machines, to create detailed images of the human body.