  Nuclear pairing correlations are known to play an important role in various
single-particle and collective aspects of nuclear structure. After the first
idea by A. Bohr, B. Mottelson and D. Pines on similarity of nuclear pairing to
electron superconductivity, S.T. Belyaev gave a thorough analysis of the
manifestations of pairing in complex nuclei. The current revival of interest in
nuclear pairing is connected to the shift of modern nuclear physics towards
nuclei far from stability; many loosely bound nuclei are particle-stable only
due to the pairing. The theoretical methods borrowed from macroscopic
superconductivity turn out to be insufficient for finite systems as nuclei, in
particular for the cases of weak pairing and proximity of continuum states. We
suggest a simple numerical procedure of exact solution of the nuclear pairing
problem and discuss the physical features of this complete solution. We show
also how the continuum states can be naturally included in the consideration
bridging the gap between the structure and reactions. The path from coherent
pairing to chaos and thermalization and perspectives of new theoretical
approaches based on the full solution of pairing are discussed.
