Much improved rewrite of the Bloch Simulator

A brief introduction to MRI

Would you ever describe an arrow pointing to the right as pointing either up or down? If you are teaching NMR or MRI, there is a good chance you do just that, and expect your students to understand. Frequently misunderstood QM is responsible. Nuclei in thermal equilibrium are not in the spin-up or the spin-down state, for example, but in almost random mixtures (superpositions) corresponding to a near-spherical distribution of orientations. And nuclear magnetic resonance involves no "quantum jumps".