Bible answer for - What is the universe expanding into?

We have an answer for what the universe is expanding into with my hypothesis (firmament) which is both scientific and biblical based as well as also pointing out the possibility of there already being the scientific data to support this hypothesis and when validated there will also be a likely explanation for the tunnel that those people travel through who have a near-death experience (NDE). Then too, there are a few challenges to Bible translation veracity that is negated as well as an overall reinforcement of the authority of scripture in general while being in perfect agreement with scientific theory.