I will first frame my response by acknowledging that I am aware that philosophical speculation is somewhat frowned upon here. I come here mostly just to browse and better aquaint myself with the thinking shared by the more hard science minded. I think the 'stick to real science' policy serves this forum well in that it serves to protect the forum's integrity and keep out the woo woos. I still miss the philosophy forums, but i get my fix for that elsewhere.
Disclaimer: I'm just a librarian armed with a curious and inquiring mind.
Regarding your question then, Ben, I think a telling approach might be a reframing of your query. I propose asking instead, "How can all that is not be infinite?" or "How would it be possible for there to be a boundary to all that exists?" It's a case of there not really being a way to rationally get around infinite causal regress. In order to deny actual infinity one must posit a beginning and bounding limits to actual reality. We concede, of course, that reality is limitted in the one sense to what is actually possible and that what is actually possible is circuitously restricted by actual reality. One would necessarily, both epistemologically and in order to account for actual reality, have to posit something from nothing.
No. Don't worry. I'm not going there.
Without getting too far into the semantics surrounding 'nothing', if we wish to account for anything and accept that absolute nothing represents a state wherein there are no degrees of freedom whatsoever, then nothing could not in any way be anything other than nothing. There would be no possibility of anything ever being able to come from nothing as there would be nothing that could undergo change in order to become something other than nothing.
Given that we must accept the simple tautology that existence exists, then existence must necessarily have derived from prior something, and that something must necessarily have been sufficient to account for what actually is.
One could posit that all is static and that change does not occur, but I'm not suggesting that we go down that dark path either.
No. I don't think this calls for any supernatural explanations either. I'm not contortionally twisting my thinking or yours to go in that direction. Not to worry.
Nothing suggests or necessitates positing anything 'outside' since we cannot rationally have anything beyond all that exists. That would imply a boundary again and boundaries can only frame finite, localized entities within the necessarily always greater all that is - which, again, would have to be actual infinite reality.
I do understand that there cannot be observational confirmation that existence must be infinite. It comes down to determining what must be the null hypothesis is this regard. It would seem that since all that has ever been observed has been observed within greater spacial, mathematically modeled or epistemologically constructed contexts, and within always greater causal/temporal reference frames, then reality would seem to be implied by infinite causal regress to be infinite.
