ABSTRACT
Modern scientific cosmology started in 1917 when Einstein applied the general theory of relativity to the cosmos. In 1993 a former President of the Royal Astronomical Society pointed out that from the mass of astronomical observation it could be that only ‘two and a half facts’ are really vital for cosmology. It must be clear by that in the great issues of cosmology there are and will always remain uncertainties, as well as topics which are essentially matters of opinion. The intrinsic incompleteness in cosmology is partly centred on the beginning, which is beyond normal scientific investigation. Newton combined local and astronomical mechanics, and that yielded the impressive structure of Newtonian cosmology. At several periods in history it has been thought that some object was uniquely qualified to be considered the centre of the universe: the earth, the sun, and our own galaxy have been in that position.
