History and Problems of the Standard Model in Cosmology

Since the beginning of the 20th century, a continuous evolution and perfection of what we today call the standard cosmological model has been produced, although some authors like to distinguish separate periods within this evolution. A possible historical division of the development of cosmology into six periods is: (1) the initial period (1917-1927); (2) the period of development (1927-1945); (3) the period of consolidation (1945-1965); (4) the period of acceptance (1965-1980); (5) the period of enlargement (1980-1998); and (6) the period of high-precision experimental cosmology (1998-now). The last period started with a epistemological optimism that has declined with time, and the expression "crisis in cosmology" is now stubbornly reverberating in the media. The initial expectation of removing the pending minor problems arising from the increased accuracy of measurements has backfired: the higher the precision with which the standard model tries to fit the data, the greater the number of tensions that arise, the problems proliferating rather than diminishing.