In my opinion, "before the bigbang" is an oxymoron. Big Bang is when Universe started, and time is inherent to existence as we know it. If the definition of Universe is "Universe is all that exists", which is the only valid definition, then we can derive that nothing can exist outside of the Universe, before or after it, and that includes time. This also answers the fundamental question that religious people ask:"If there was no God, what trigerred Big Bang? Are you trying to tell me that something was created out of nothing?" No, I'm not (one of Thomas Aquinas' "proofs" of God's existence). They are assuming the cause-effect pattern inherent to THIS Universe. Without it, there is no time, therefore no cause-effect. Only in THIS universe do processes need causing processes. Big Bang needs no cause, since it is not an effect.