This became a basis for what is now called the old quantum theory.

Throughout the 1910s and well into the 1920s, many problems were attacked using the old quantum theory with mixed results.

They are collectively known as the old quantum theory.

But his answer, like all other calculations in the old quantum theory, was only correct for large orbits.

This phase is known as Old quantum theory.

But once the old quantum theory was a bit better understood, no theoretical argument could be found to justify Weiss's value.

This constant is neglected in the derivation of the old quantum theory, and its value can not be determined using it.

The old quantum theory provides no means to calculate the intensities of the spectral lines.

They can be used to show the superiority of formal quantum mechanics over old quantum theory.

The theory also generated great discussion and renewed attention to the difficulties in the foundations of the old quantum theory.

The old quantum theory is a collection of results from the years 1900-1925 which predate modern quantum mechanics.

The old quantum theory had some limitations:

Old quantum theory went on to modify classical mechanics in an attempt to deduce the Bohr model from first principles.

He derived equations for the line intensities which were a decided improvement over Kramers' results obtained by the old quantum theory.

The basic idea of the old quantum theory is that the motion in an atomic system is quantized, or discrete.

The old quantum theory was formulated only for special mechanical systems which could be separated into action angle variables which were periodic.

Bohr had developed the "old quantum theory" of atomic matter; Heisenberg announced the famous uncertainty principle in 1927.

This condition was the foundation of the old quantum theory, which was able to predict the qualitative behavior of atomic systems.

The new quantization rule was assumed to be universally true, even though the derivation from the old quantum theory required semiclassical reasoning.

In the old quantum theory prior to quantum mechanics, electrons were supposed to occupy classical elliptical orbits.

The old quantum theory was formulated by equating the quantum number of a system with its classical adiabatic invariant.

The simplest system in the old quantum theory is the harmonic oscillator, whose Hamiltonian is:

They all, as well as Wolfgang Pauli, were developing the new quantum mechanics that would eventually supersede the old quantum theory.

While at Chicago, he took a course under the Nobel Prize-winning physicist Robert A. Millikan, which exposed him to the old quantum theory.

It was later understood that the old quantum theory is in fact the semi-classical approximation (also called quasi-classical) to the Schrödinger equation whose limitations are still under investigation.