Ironically, perhaps the closest to a scientific viewpoint we have on this is the near-death experience, the DMT experience, or the experience of passing through the bardos as described by the practice of "conscious dying" and coming back again by Eastern yogis.

Yet most people who credit themselves as "scientists" discredit these experiences for their "metaphysical" connotations. What they don't realize is that everything is one thing, and nothing requires metaphysical explanation, no matter how unusual it seems to our current paradigm.