This is not an answer to the question. The implication from what you said is that the law of conservation of matter and energy is not true when applied to “univ

This is not an answer to the question. The implication from what you said is that the law of conservation of matter and energy is not true when applied to “universe splitting”. Which comes back to the original question. So where does it come from? I assume that proponents of many worlds have an answer for this, though I don’t know what it is. I am doubtful that it’s “magic” or just “conservation does not apply”. > conservations laws would probably not apply for that device The law of conservation applies to the universe, not the measurement device.