Getting the numbers right - the lonely struggle of Rydberg

Johannes Rydberg, one of the grandfathers of modern-day physics and chemistry, whose scientific carrier began in the late nineteenth century is discussed. Rydberg is most famous of his studies of the atomic spectra of elements like hydrogen. Atoms like sodium, that have only one valance electron, are still referred to as 'Rydberg atoms' and are the focus of intense research. The original theories of atomic structure were deducted from the spectrum of sunlight. The research has shown that the Ryberg's equation does not apply precisely to the spectra of more complex atoms, because their outer electrons interact significantly with their inner electron shells.