Abstract This chapter discusses how the new quantum theory took care of some of the failures of the old quantum theory and how it put the old theory’s successes on a firmer basis. Examples in the former category are the new theory’s resolution of the problems the old theory ran into with the anomalous Zeeman effect and helium (giving the wrong value for its ground state energy and being unable to explain the spectroscopic divide between ortho- and parahelium). Examples in the latter category are the fine structure in hydrogen and the Stark effect. The chapter also discusses some examples of Kuhn losses, instances where the new theory (at least initially) could not account for phenomena explained by the old one.Abstract This chapter discusses how the new quantum theory took care of some of the failures of the old quantum theory and how it put the old theory’s successes on a firmer basis. Examples in the former category are the new theory’s resolution of the problems the old theory ran into with the anomalous Zeeman effect and helium (giving the wrong value for its ground state energy and being unable to explain the spectroscopic divide between ortho- and parahelium). Examples in the latter category are the fine structure in hydrogen and the Stark effect. The chapter also discusses some examples of Kuhn losses, instances where the new theory (at least initially) could not account for phenomena explained by the old one.

Aug 17, 20230 citations

Microwave Technique for Determining the Fine Structure of the Helium Atom

Willis E. Lamb

A new technique of microwave spectroscopy is proposed for application to excited states of short lifetime. If atoms are excited by electron bombardment, closely-spaced energy levels may be unequally populated. The radiation emitted in decay to lower states may have an angular distribution and polarization character correlated with the direction of bombardment. When such atoms are acted on by radio-frequency fields, transitions may occur between excited states which cause an observable change in the pattern of decay radiation. An analysis is made of the possibility of applying such a method to a determination of the finestructure patterns $(1snp)^{3}P_{J}(J=0, 1, 2)$ of the helium atom. After a review of previous optical spectroscopic work and theory of this fine structure, an old unsolved mystery concerning the polarization of collision light is discussed. The theory of the Zeeman effect is worked out in a form applicable to the microwave experiments. Expected transition frequencies and rf matrix elements, intensity changes and shape of resonance curves, Stark effect and singlet-triplet mixing are also considered. An estimate is made of the signal to be expected in the experiment described in the following paper.A new technique of microwave spectroscopy is proposed for application to excited states of short lifetime. If atoms are excited by electron bombardment, closely-spaced energy levels may be unequally populated. The radiation emitted in decay to lower states may have an angular distribution and polarization character correlated with the direction of bombardment. When such atoms are acted on by radio-frequency fields, transitions may occur between excited states which cause an observable change in the pattern of decay radiation. An analysis is made of the possibility of applying such a method to a determination of the finestructure patterns $(1snp)^{3}P_{J}(J=0, 1, 2)$ of the helium atom. After a review of previous optical spectroscopic work and theory of this fine structure, an old unsolved mystery concerning the polarization of collision light is discussed. The theory of the Zeeman effect is worked out in a form applicable to the microwave experiments. Expected transition frequencies and rf matrix elements, intensity changes and shape of resonance curves, Stark effect and singlet-triplet mixing are also considered. An estimate is made of the signal to be expected in the experiment described in the following paper.

Physical ReviewJan 15, 195752 citations

New Aspects

Wolfram Schommers

Elsevier eBooksOct 12, 20182 citations

Ensembles and Effects

Günther Ludwig

Springer eBooksJan 1, 19831 citation

Introducing quantum mechanics through its historical roots: The hydrogen Rydberg atom viewed through the lens of the old quantum theory

Michael G. Littman, E. Gordis, Pavel Zhelnin +1 more

Solutions of Schrödinger's equation for Rydberg states of hydrogen are shown to display patterns that can be understood semi-classically within the framework of Bohr-Sommerfeld planetary orbits and de Broglie's concept of matter waves. Using n = 10 and n = 100 quantum levels we show how de Broglie-wave-analyzed Kepler orbits can be matched to excited-state wavefunctions and charge distributions. Making the connection between the old and new quantum theories can help beginning students develop an intuition about quantum mechanics and allow them to develop an appreciation of how Schrödinger's wave mechanics was stimulated by the theories of his predecessors.Solutions of Schrödinger's equation for Rydberg states of hydrogen are shown to display patterns that can be understood semi-classically within the framework of Bohr-Sommerfeld planetary orbits and de Broglie's concept of matter waves. Using n = 10 and n = 100 quantum levels we show how de Broglie-wave-analyzed Kepler orbits can be matched to excited-state wavefunctions and charge distributions. Making the connection between the old and new quantum theories can help beginning students develop an intuition about quantum mechanics and allow them to develop an appreciation of how Schrödinger's wave mechanics was stimulated by the theories of his predecessors.

American Journal of PhysicsMay 1, 20235 citations

(1snp)^{3}P_{J}(J=0, 1, 2)

of the helium atom. After a review of previous optical spectroscopic work and theory of this fine structure, an old unsolved mystery concerning the polarization of collision light is discussed. The theory of the Zeeman effect is worked out in a form applicable to the microwave experiments. Expected transition frequencies and rf matrix elements, intensity changes and shape of resonance curves, Stark effect and singlet-triplet mixing are also considered. An estimate is made of the signal to be expected in the experiment described in the following paper.