Understanding Spin: the field theory of magnetic interactions

Spin is commonly thought to reflect the true quantum nature of microphysics. We show that spin is related to intrinsic and field-like properties of single particles. These properties change continuously in external magnetic fields. Interactions of massive particles with homogeneous and inhomogeneous fields result in two discrete particle states, symmetric to the original one. We analyze the difficulties in quantum mechanics to give a precise spacetime account of the experiments and find that they arise from unsuitable analogies for spin. In particular from the analogy of an angular momentum. Several experiments are suggested to check the model against the standard model in quantum mechanics.