No . The Big Bang is not some complicated mathematical unknown . It ' s actually very simple and based entirely on observation . Sure , you have to trust at the collected data is accurate , but the thing is , it ' s been verified by telescopes all over the world . The cosmic background radiation is observable by you if you tune a tv or radio to static . It ' s also not necessarily true . It ' s the best fit for current observations of the red shift of galaxies , but it ' s based entirely on the assumption of running that backwards to a singular point to date the universe . Thats a pretty fair assumption to make , but it ' s by no means confirmed as a certainty , although we do currently assume it as fact because it ' s useful to do so and nothing has contradicted it yet . So yes , on the one hand it might be a belief somebody holds , but it ' s not an unknowable or unprovable one , and it can be explained in laymans terms very easily and with multiple lines of evidence .