Lex Fridman interviews Sean M. Carroll on his new quantum mechanics book.
Carroll says that there are three contenders for a QM interpretation: (1) many-worlds, (2) hidden-variables, and (3) spontaneous collapse.
None of these has a shred of empirical evidence. We know that hidden variable theories have to be non-local, and no one has ever observed such a nonlocality. Spontaneous collapse theories contradict quantum mechanics.
After some questions, he admitted another: (4) theories concerned with predicting experiments!
He derided (4) as "epistemic", and complained that those theories (like textbook Copenhagen quantum mechanics) are unsatisfactory because they just predict experiments, and fail to predict what is going on in parallel universes or ghostly unobserved particles.
He also complained that under (4), two different observers of a system might collect different data, and deduce different wave functions.
Yes, of course, that is the nature of science.
Carroll's problem is that he has a warped view of what science is all about. He badmouths theories that make testable predictions, and says that we should prefer a theory that somehow tells us about "reality", but doesn't actually make any testable predictions.
He is a disgrace to science.
Update: See also this Google Talk video, where Carroll makes similar points.
He compares his 3 leading interpretations of QM to the 3 leading Democrat contenders for the White House. Maybe that is a fair analogy, and the leading Democrat contenders are all unfit for office, for different reasons.