Nerd alert! -more spooky Quantum stuff

[HappySkeptic]

What about Many-Worlds Interpretation? Which is what Sean Carroll believes is the correct one (not Bohm's interpretation).

Well, the Everette interpretation also isn't deterministic. There's no way to know which way the world will split for you. It has the advantage of taking the Schrodinger equation seriously, but so does decoherence.

I do not like Many-Worlds, and I don't know why some top physicists do.  I know Lee Smolin hates it too.  His idea is many potential realities within one universe, not one reality each in an infinite number of splitting universes.  I agree.

As for decoherence theory -- it is clearly correct, but it is not a QM interpretation (it can be included in any interpretation).  Decoherence theory does not provide for wavefunction collapse.  You still need an interpretation to explain collapse.

For those other readers that aren't familiar, decoherence theory states that each quantum interaction causes a new superposition.  After a particle has interacted with many other non-correlated particles, a measurement (which is just another superposition) of the original particle will be seen to experience a phase noise.  In QM terms, it diagonalizes the Hamiltonian, making a measurement of that particle appear classical instead of quantum.  However, there never is anything classical -- its quantum all the way down.  This "all the way down" is a problem, though, when applied to the entire universe.  It means there are infinite histories, and none ever really get chosen.  This isn't the universe we live in, so some sort of collapse must occur.

Now, it could be some self-collapse model involving wavefunction non-linearity (likely unworkable, as it violates energy conservation), or some sort of interaction with Gravity (from Penrose). 

I have seen apparent-collapse models (Montevideo interpretation) which allow for multiple realities, but when multiple particles share more and more information, the realities "for them" converge.  Reality is defined by the information relationships (what does one ensemble of particles "know" about another), not by a single absolute reality.  It fits very well with decoherence theory.  I like that one, but it hasn't attracted many followers.