Centenary of Alexander Friedmann’s Prediction of the Universe Expansion and the Quantum Vacuum

We review the main scientific pictures of universe developed from ancient times to Albert Einstein and underline that all them treated as a stationary system with unchanged physical properties. In contrast this, 100 years ago Alexander Friedmann predicted expands starting point infinitely large energy density. briefly discuss meaning this prediction its experimental confirmation consisting discovery redshift in spectra remote galaxies relic radiation. After mentioning horizon problem theory hot universe, inflationary model is considered connection concept quantum vacuum an alternative inflaton field. The accelerated expansion discussed powered by cosmological constant originating vacuum. conclusion made since Friedmann’s radically altered our picture world comparison previous epochs, his name should be put on par names Ptolemy Copernicus.