Since we understand that there are several dozen models for the universe, we must conclude that it isn't an easy process to construct a cosmological model from our observations. Is it comparative to ten people observing an accident? Do we not often get ten different renditions of what happened? How much more difficult is it for ten scientists to look into the cosmos and tell us what happened after the fact.
What is Microwave Background Radiation (MBR)? Our universe according to the BB theory, began with what George Gamow called the "primeval fireball." During the first second of existence, the universe went through various changes. Over several thousand years, matter changed as space expanded and cooled.