I haven't read the book... synopsis from Wikipedia..In this book, Carroll examines the reasons why people misunderstand quantum mechanics and advocates a version of the many-worlds interpretation, while objecting to the views often grouped together as the Copenhagen interpretation.
....many world interpretation supports a universal wave function..if am not wrong, that means any other wave function Is independent;that means no collapse to the other...if so, there are many worlds for each wave function....to me these increases confusion...how do this 'many worlds' interact?
Me am of the opinion that there might be one universal wave function that collapsed to many wave functions(not many worlds)...these many wave functions interact through wave function collapse...after all,so far it's generally accepted that it was a single Big bang.
Therefore I regard this..
as an over statement .