It is a reasonable assumption that "We live in a physical world."
No it isn't. Simply "assuming" a thing reasonable implies (possibly equally, even more reasonable) competing theories.
Like every appeal to religious belief ever, one simply presumes the conclusion because they've never seriously accepted the premise as "reasonable" to begin with. I sure don't know exactly how every signal is sent, received, or processed in living things, but we know one helluva lot more about it now than we did fifty years ago. Who knows how much we'll have figured out in another fifty years? I think one helluva lot x one helluva lot would be a reasonable estimate - given we don't largely kill ourselves off in the meantime.
Fact: We live in a physical world.
Fantasy: We live in a non-physical world.
If one rejects that (for our purposes) a scientifically empirical, unfalsifiable, consensus finding remains what meaningfully separates established "fact" from fiction, the "known" from all the wackiness proposed, then "God" help them.. to steer well clear of those like me.