The empirical study reveals for the first time the fea-tures of the simultaneity of the processes of growth of scientific knowledge, objectified in the texts of defended dissertations. The re-sults are achieved through statistical analysis using the method of paral-lel periodization of single-quality dynamics of time series indicators of dissertation defenses in the humanities, technical, chemical and eco-nomic sciences. The study is based on 59 479 dissertations for the peri-od from 1980 to 2022. Simultaneity is understood as a formal charac-teristic of the spatio-temporal deployment of the dynamics of production of various scientific knowledge and is represented as a formation characterized by a set of components in the form of natural and artificial processes that determine their growth and development. The natural component is predetermined by the paradigmatic orientation and theoretical and epistemological preferences of the subjects of scien-tific activity. The artificial component depends on the political, eco-nomic and socio-psychological factors of influence, transformation of public institutions. The analysis of the artificial component of simulta-neity was carried out, which influenced the peculiarity of the processes of dissertation defenses, characterized by wave-like lines of their growth and decline in two episodes. The first growth: from 1980 to 1987; decline: from 1988 to 1993. The second growth: from 1996 to 2007; decline: from 2008 to 2022. The practical significance of the work lies in the fact that the concept of simultaneity can be used as a means of coordination and planning of dissertation defense flows in research and design organizations.
dynamics; dissertation; defense; knowledge; natural; artificial; science; simultaneity; growth; development.