> I read the essay, and I disagree that the multiverse is necessary. Read his book 'Our mathematical Universe', he explains there why these are actual separate

> I read the essay, and I disagree that the multiverse is necessary. Read his book 'Our mathematical Universe', he explains there why these are actual separate multiverses. I agree it's somewhat a matter of interpretation whether it's truly "multi" or a single entity. But if the domains are separate enough, it's probably best to think of them as different universes.