I don't think that criticism really understands what Everett says-- the evolution of the universal wavefunction is unitary. There is no "splitting". There is on

I don't think that criticism really understands what Everett says-- the evolution of the universal wavefunction is unitary. There is no "splitting". There is only uncertainty about what part of phase space you are in (and any measurement that tightens your certainty in one axis of phase space will broaden it along some other axis).