PART II

SPECTRAL EVIDENCES

Anomalous Zeeman Effect

Pauli in his Nobel Lecture discussed his work with the anomalous Zeeman effect when he started to work with Bohr in the fall of 1922.

We know now that at the time one was confronted with two logically different difficulties simultaneously.  One was the absence of a general key to translate a given mechanical model into quantum theory which one tried in vain by using classical mechanics to describe the stationary quantum states themselves.  The second difficulty was our ignorance concerning the proper classical model itself which could be suited to derive at all an anomalous splitting of spectral lines emitted by an atom in an external magnetic field.  It is therefore not surprising that I could not find a satisfactory solution of the problem at that time....I therefore tried to examine again critically the simplest case, the doublet structure of the alkali spectra. According to the point of view then orthodox, which was also taken over by Bohr....a non-vanishing angular momentum of the atomic core was supposed to be the cause of this doublet structure.

In the autumn of 1924 I published against this point of view, which I definitely rejected as incorrect and proposed instead of it the assumption of a new quantum theoretic property of the electron, which I called a 'two-valuedness, not described classically'...Uhlenbeck and Goudsmit's idea of electron spin, which made it possible to understand the anomalous Zeeman effect simply by assuming that the spin quantum number of one electron is equal to 1/2 and that the quotient of the magnetic moment to the mechanical angular moment has for the spin a value twice as large as for the ordinary orbit of the electron. ... I stressed the circumstances that I was unable to give a logical reason for the exclusion principle or to deduce it from more general assumptions.  I had always the feeling and I still have it today, that this is a deficiency [1].         

The splitting of spectral lines when a light source is placed in a magnetic field was discovered by Peter Zeeman in 1896.  A "normal Zeeman effect" was observed for all lines belonging to a singlet system.  The normal Zeeman effect lines split into two or three lines depending on the direction of observation.  Current theory attributes this splitting of the singlet state to the orbiting angular momentum of the electron. In the singlet D₁ line of sodium (2S_1/2----2P_1/2) we find the normal Zeeman effect. 

A more complex splitting occurs in multiplicities greater than one.  When we move to the D₂ line of the Sodium doublet (2S_1/2------2P_3/2) anomalies occur. "One speaks of the anomalous Zeeman effect when the angular momentum and magnetic moment of the two terms between which an optical transition occurs cannot be described by just one of the two quantum numbers s or l (or S or L), but are determined by both" [2].

"In anomalous Zeeman splitting, other values of g_j than 1 (Orbital magnetism) or 2 (spin magnetism) are found" [3]. "The anomalous effect must be attributed to a nonclassical magnetic behavior of the electron spin.  ....Thus the spin generates twice as much magnetic moment, relative to its angular momentum" [4].  Another authority on spectra, Gerhard Herzberg, takes a similar position. "from the above discussion (line splitting will vary according to the values of J, L, and S in the upper and lower states ...term type) it is clear that the double magnetism of the electron is fundamental to the explanation of the anomalous Zeeman effect" [5].

This has been the position of physics for many years that the anomalous Zeeman effect is a result of the non-classical double magnetism of the quantum electron. However, the use of a new Circular Model of the Atom incorporates a dipole elemental buildup of the elements suggesting an alternative approach to the origin of the anomalous Zeeman effect. Attribution of double magnetism to the electron  is unjustified in light of the new dipolar circular model. 

In the Circular Model of the Atom the dipole buildup of the periodic table of the elements occurs within distinct and separate positive and negative multiplicities sections. Superimposing the anomalous Zeeman effect spectral lines upon the circular table demonstrates that the doublet lines originate from the negative portion of the dipole field thus eliminating the need for double magnetism of the electron.

Herzberg in his analysis of anomalous Zeeman effect indicates it only happens when we get splitting of term types in upper and lower states.  What is the cause of the splitting? In the new dipole Circular Model of the Atom this process occurs naturally and sequentially whenever spectral line states originate in the negative field without resorting to or imputing a double magnetism to the electron as present quantum theory requires.        

[1] Pauli, W., 1945. Exclusion Principle and Quantum Mechanics. Nobel Prize Lecture, emphasis added.

[2] Haken, H. & Wolf, H. C., 1984. Atomic and Quantum Physics. New York: Springer-Verlag, p. 206, emphasis added.

[3] Haken, H. & Wolf, H. C., 1984. Atomic and Quantum Physics. New York: Springer-Verlag, p. 207, emphasis added.

[4] Zeeman Effect. In: McGraw Hill Encyclopedia of Physics, New York: McGraw Hill, pp. 1279-1280, emphasis added.

[5] Herzberg, G., 1944. Atomic Spectra and Atomic Structure. New York: Prentice Hall, p. 112. 

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