Why all the nutcases?

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  • #76
andrewgray
It is not an inconsistency... The electron has both angular momentum and spin (=magnetic moment) and therefore there is nothing inconsistent (that is: they were never thinking about spinning things).
You say that the electron spin not spinning is not an inconsistency.

OK then.

So the inconsistency is that the electron's magnetic moment is not a "moment"?


moment n. The product of a quantity and the distance to a particular axis or point.
 
  • #77
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One of the properties of an electron is that it has a magnetic moment...
What is inconsistent about that?

You do an experiment involving a magnet and an electron beam. It turns out the electrons react to the field. They want to line up to it due to their mag. moment (i.e. they experience a torque). I don't see the inconsistency in that.
Perhaps I'm not catching what you mean by inconsistent...

To refer to feynman: "We thought about it, very hard. I can tell you what we found. You don't like it? Tough. Go somewhere else, to a different universe where the rules are simpler, or nicer or more philosophical"

(quote taken from the video taping of his QED lectures in Auckland, New Zealand, first lecture. Haven't seen them before?....it's a must)
http://www.vega.org.uk/series/lectures/feynman/index.html [Broken]
 
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  • #78
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Originally posted by heumpje
video taping of his QED lectures in Auckland, New Zealand, first lecture. Haven't seen them before?....it's a must)
http://www.vega.org.uk/series/lectures/feynman/index.html [Broken]
Thanks. Great stuff.
 
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  • #79
russ_watters
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Originally posted by andrewgray
You say that the electron spin not spinning is not an inconsistency.

OK then.

So the inconsistency is that the electron's magnetic moment is not a "moment"?


moment n. The product of a quantity and the distance to a particular axis or point.
No, I think (I'm a little thin on this one) that an electron has a magnetic moment AND a property called "spin." They are two different properties.
 
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Originally posted by pelastration
Thanks. Great stuff.
Yes, amazing isn't it. That you can find this sort of stuff on the web for free...let's just say I tought that, that only applied to porn
 
  • #82
russ_watters
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Originally posted by heumpje
Auch... That IS sort of a miss there russ. The spin IS the magnetic moment.
D'oh.
 
  • #83
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Isn't the measured magnetic moment predicted here by Dirac (accurately but approximately) proportional to (not the same as) the spin?
 
  • #84
Tom Mattson
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Originally posted by Loren Booda
Isn't the measured magnetic moment predicted here by Dirac (accurately but approximately) proportional to (not the same as) the spin?
Yes, that's right. The magnetic moment is not identical to the spin. A particle with spin has a magnetic moment because it also has a charge.
 
  • #85
russ_watters
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So then I wasn't completely wrong?
 
  • #86
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To be completely, entirely clear on this:

(mu)S=-gs*(mu)BS/hbar

So, the magnetic moment of an electron is proportional to the spin S, with in the proportionality factor gs=2 (the gyromagnetic ratio), [mu]B=9.2*10-24 A*m2 the Bohr magneton and hbar planck's constant divided by two pi. (BTW: somehow you can't do math symbols anymore....The mag. moment and the spin are vectors)

Although the Spin points in the opposite direction as the mag. moment (observe the minus sign) I called it equal since there are only some constants as proportionality factors....
 
  • #87
andrewgray
You say that the electron spin not spinning is not an inconsistency.

OK then.

So the inconsistency is that the electron's magnetic moment is not a "moment"?


moment n. The product of a quantity and the distance to a particular axis or point.
One of the properties of an electron is that it has a magnetic moment...
What is inconsistent about that?

You do an experiment involving a magnet and an electron beam. It turns out the electrons react to the field. They want to line up to it due to their mag. moment (i.e. they experience a torque). I don't see the inconsistency in that.
Perhaps I'm not catching what you mean by inconsistent...
Reply:

Well, in addition to the impossibility of concentrating angular-momentum inside an electron's volume to make electron "spin", there is no room inside an electron for any electric current to have a large enough "moment" to make up a "1/2 quanta of magnetic moment".

Therefore, the electron's magnetic "moment", if it exists, is not a "moment".

Seems inconsistent to me.


P.S. You cannot do your experiment with a magnet and an electron beam (the Stern-Gerlach experiment). This experiment can only be done with electrically neutral particles. In addition, we have proposed a "Stern-Gerlach Killer Experiment" that allows the recovery of the continuous (non-quantized) nature of microscopic angular momentum. See www.modelofreality.org/Sect8_1.html


andrewgray AT modelofreality.org
 

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