Why is wave-function collapse still being taught in quantum mechanics?

I don't really understand why wave-function collapse is still being taught while we seem to have better interpretations of QM available nowadays.

During the early development of quantum mechanics the measurement problem was a heavily debated topic, resulting in a general acceptance of the so-called Copenhagen interpretation. The two main problems with it are

• It is not clear what physically defines an observation.


• There is a certain faster than light interaction, thought this does not include faster than light travel of information.

Furthermore, the idea that the universe is nondeterministic was not appealing to some, for example to Einstein.

Since 1957 we have the "Many-worlds" interpretation of QM which resolves both these problems, makes QM deterministic again and gives a (IMO) much more physical interpretation. The original name Hugh Everett gave to his theory is "Correlation Interpretation" which I find actually more clear. Perhaps "Observer Entanglement" would be even more natural in the current idiom.

This theory was first mostly ignored, and even now seems to still not get the attention it deserves. Why are teachers often still teaching wave-function collapse, with all its shortcomings, when they teach QM?

Answer

1. 
   
   

   There are many interpretations, and while there are good arguments in favor of one or another, they are currently not distinguished experimentally. Therefore it is often considered prudent to leave the question of which interpretation is best to the field of philosophy, and focus in a physics course on the falsifiable aspects of the theory. The field of quantum interpretations is too deep to do the subject justice in an ordinary quantum mechanics course.

   
   


2. 
   

   The "Copenhagen Interpretation" is not very well-defined, but given point #1, it has several advantages over the others. One is historical inertia, but more importantly is its minimalism and instrumentalism. In its "textbook version," it avoids taking a position on the philosophical aspects of the theory, and focuses on calculation. It is often associated with the "Shut up and calculate!" mantra. "Collapse" of the wavefunction is not taken too literally as a dynamical process, but merely as a calculational tool. Quantum textbooks/courses tend not to dwell on the philosophy of Bohr or Heisenberg, and rather leave interpretation open to student preference should they pursue it through other resources.

   
   


3. 
   

   The philosophical problems with the interpretation, such as describing the experimental apparatus or observer quantum mechanically, are currently not an issue for experimentalists testing the predictions of quantum mechanics, though in response to some comments perhaps I should add that some interpretations tend to be preferred by different subfields of physics, for example unitary wave function evolution is more useful for cosmology, a case where there are no observers external to the wave function of the universe to cause it to collapse. Something similar might be said for quantum computation, where something like an AI could potentially be put in superposition.