A Danish astronomer Tycho Brahe (1546–1601) admired Copernicus’ work especially for his mathematical solutions. He believed, however, that the elegance of the heliocentric model was too high a price for abandoning the idea of an immovable Earth.

Johannes Kepler (1571–1630) became a supporter of Copernicus’ heliocentric theory thanks to Michale Maestlin, who introduced him to the arcana of astronomy at the University of Tübingen. 

Most of the cosmological models under consideration are based on the Copernican principle whereby, in a large scale, the Universe looks the same, regardless of the position of the observer. It implies that the cosmological parameters such as the pace of expansion of the Universe (Hubble’s constant), the chemical composition of matter, the average density of galaxies, the background radiation temperature and the mass distribution of stars turn out to be the same, regardless of location.

The standard Big Bang model is a generally adopted evolutionary theory of the Universe. According to this theory, about 13.7 billion years ago the Universe was filled with very dense and very hot plasma, in which there was a thermodynamic equilibrium between the elementary constituents of matter and radiation (photons).

One of the unresolved issues in Physics and Cosmology is the problem of the origin of laws of nature, values of fundamental constants and the alleged extraordinary coincidence between the values of these constants. Some believe that if the values of fundamental constants like the speed of light or Planck's constant were a little different, life could not appear or there could not be stars and planetary systems. Another mystery is why the Big Bang occurred and where the energy of this event came from.

The standard Big Bang model has excellently passed many observational tests, also of the experimentum crucis nature. Cosmologists, however, are aware of its shortcomings.