And of course, going the other way from 'our own being': organs, tissue, chemicals, cells, atoms, sub-atomic particles, their particles (quarks, etc.), ????

But the further we go we never see 'nothingness', because...well...it's nothing. The most plausible (under our current scientific and logical understandings) is that it probably is a component of something bigger (multiverse, etc.), but then again our understanding is greatly limited in terms of the cosmos. But, when scientists say 'it' (the universe as a totality of all things existing) is expanding into 'nothingness', I think they really mean nothingness (because they're talking about the expansion of space-time). I just think I want to know the reasoning going on there from someone more apt in physics or astronomy.

My guess is that, 'it' (as a positive space-time existence) just 'is' and is expanding; not into anything but just is...well..growing. But this is a very ill-informed guess. Perhaps it is possible for something to expand from nothing. For example, I remember listening to a philosopher named Alan Watts where he attempted to explain the concept of something from nothing. He was talking about an analogy of how sound comes from nothing (absence of sound), or in this case, silence. Without the understanding of silence, one cannot have sound. When I say something, it just pops out from nothing. Likewise, existence comes from nothing; look around and just 'pop' there it is. Without nothing maybe something can't be? For example, '1' has no value if it is not superimposed over the concept that there could be '0'? I don't know...