Experts agree that Quantics has an extended algorithm for calculating probabilities of events, resulting in many confirmed predictions. But what is "behind this algorithm"? There are at least nine interpretations on which no considerable consensus exists. (Adapted from Quantum Mechanics and the Particles of Nature, by Anthony Sudbery.)

1. Copenhagen Interpretation:
2. Literal Interpretation: This is found in most textbooks, treating each state vector (or its corresponding point in the projective geometry of state space, as described in (8), below) is regarded as objective as, say, momentum and kinetic eneryy in classical physics. The aspects of indeterminacy and nonseparability of state are accepted as facts about the world. The objection to this interpretation is that (as noted in (8)) no state vector can be identified as corresponding to a given physical state.
3. Objective Interpretation (modifying Literal Interpretation):
4. Epistemic Interpretation:
5. Ensemble Interpretation:
6. Many Worlds Interpretation:
7. Quantum Logic Interpretation: Each wave function, Y can be treated as a state vector (vector representing some quantic state), their collection forms a state space (a complex vector space with inner product. However, correspondence between state vectors and quantic states is not one-one, since the current mathematics is what elsewhere I describe as t-math, which respect only type, not tokens of type or ordering. Hence, any multiple of a state vector is equivalent to a single state vector, and we deal with its equivalence class, and the collection of these classes forms a projective geometry, which, in turn, is equivalent to a modular lattice theory, in which the distributive law fails. This has been interpreted as meaning that quantics has a different logic than classical physics, which "obeys" classical logic (including distributivity), just as general relativity fits a non-Euclidean (Riemannian) geometry, different from the Euclidean geometry of non-Relativistic physics. Since it is argued that classical logic is used otherwise in quantics, this interpretation has few adherents among physicists than any of the others. What is not considered is that nondistributivity follows from the polarization of waves acting as a favored element in a "pointed" set, as discussed elsewhere at this Website.
8. Hidden Variables Interpretation: All observables have precise values determined by hidden variables whose discovery will remove the present appearance of indeterminacy. However, Bell's theorem shows that any hidden variable theory requires instantaneous action at a distance, in conflict with special relativity.
9. Stochastic Interpretation (probabilistic with time parameter): The Schrödinger Equation has a formal similarity to a stochastic differential equation which describes the unpredictable of a particle from random impulses -- such as floating pollen particle in Brownian motion. This allows for a particle with definite position at each moment of time such that each time interval has a definite transition probability for a definite increment in this position. However, as with the HIdden Variables Interpretation, application of Bell's Theorem requires that properties of the medium (say, a fluctuating electromagnetic field) depend on the behavior of distanct particles. Also, the stochastic nature requires that the particle's wave function form at any given time depends upon its form at the initial moment -- a strange condition.