the prevailing theory among cosmologists is that the observable universe began from a point of singularity and this singularity rapidly expanded in all directions to the present universe we see today. We are, to use the anology, in a balloon expanding outwards in all directions. We have detected the Microwave Background Radiation in equal distance in all points of directions. This observation proves one of three things, that our solar system is the very center of the universe (and therefore the point of origin) or the instruments are inaccurate, or astronomers are not interpreting the data correctly.
Astrophysicists state that before the big bang, there was no vacuum of space nor time as we understand them, but that space came into existence as time passed after the big bang. This 'expansion, obviously, was three-dimensional, that is, it expanded in all directions in the spherical, not linear, so we should be able to see differences in distances of the CMB. We should, in fact, see specific regions devoid of the CMB, regions where CMBs are closer to us than other regions. Such data would support the Big Bang theory but as it is, it proves noting except the foolishness of man's perception of the world and the universe he inhabits.