David Deutsch: evaluation

Transcript context

…How do you think the many-worlds interpretation of quantum mechanics relates to the view that, just in terms of space, the size of our current universe is infinite, and therefore everything possible is happening in it? It complicates the discussion of probability, but there’s no overlap between that notion of infinity and the Everettian notion of infinity, if we are infinite there, because the differentiation (as I prefer to call what used to be called splitting) — when I perform an experiment which can go one of two ways, the influence of that spreads out. First, I see it. I may write it down; I may write a scientific paper. When I write a paper about it and report the results, that will cause the journal to split or to differentiate into two journals, and so on. This influence cannot spread out faster than the speed of light. So an Everett universe is really a misnomer because what we see in real life is an Everett bubble within the universe. Everything outside the bubble is as it was; it’s undifferentiated, or, to be exact, it’s exactly as differentiated as it was before. Then, as the bubble spreads out, the universe becomes or the multiverse becomes more differentiated, but the bubble is always finite. How do your views relate to the philosophical modal realism of David Lewis?…

Stored transcript either side of the excerpt. The highlighted words are the published quote; the surrounding text is unedited source, never generated.