In his book The trouble with physics, Lee Smolin says there is a crisis in physics, because we are not making as much progress as we use to. Perhaps what we need to do is to go back and review what we have accomplished; recheck what we believe we understand; clean up some of the messy corners.
No doubt, one of the least comfortable parts of the current knowledge that we have in physics today is quantum mechanics. This is not just me. Richard Feynman said that nobody really understands quantum mechanics. Gerard ‘t Hooft believes the quantum mechanics is not fundamental. Most physicists have some sort of a love-hate relationship with quantum mechanics.
Then why do we use it? Fact is, it works. Quantum mechanics is a mathematical formalism (not a theory) that is extremely successful in making predictions. It is an inevitable consequence of the scientific method that it would optimize mathematical formalisms or theories for their ability to make successful predictions and not for their ability to provide an understanding. If we also somehow gain the latter then it is a bonus. So if we want an understanding we need to aim specifically for it, almost as an ad hoc motive in addition to `scientific progress.’
Well that is precisely what I have in mind: to revisit quantum mechanics and try to see if one can increase our understanding of it somehow. At least one can try to remove the misconceptions that may exist. The approach is to revisit the principles on which quantum mechanics are based. What are the principles of quantum mechanics? In his two volumes on quantum field theory Steven Weinberg considered quantum mechanics as a principle in itself. However, I believe that a principle should be something simple that one can phrase in a simple sentence. The whole construct that is quantum mechanics is too complicated to pass as a single principle.
So let’s see if we can compile a list of principle that can act as foundation for the formalism of quantum mechanics. To do this I intend to discuss the following aspects that I believe play a central role in quantum mechanics:
Hopefully these discussions will not only lead to a succinct list of principles, but will also clear up some of the misleading concepts in quantum mechanics.