>>11951644it's only us in this thread
>B and H are basically exactly the same in a vacuumyes, up to a constant scaling factor that depends on your choice of units
>but the additional component "M" would result from something with a relative permeability >1.0 like a big chunk of iron getting influenced by H?Almost entirely correct, except anything with a relative permeability !=1 will have a component of M. Certain materials have an M field that actually opposes the H field and are called diamagnetic. These types of materials aren't as common, but they do exist. In the analogy given above, it would be like if the mystery object absorbed one photon for every 10 it sees, thus reducing the total B field instead of increasing it.
Keep in mind this is only in the linear case where you can use the approximation that . The graph of this B-H curve would be a line. However, your picture shows that's clearly not the case in ferromagnetic materials, and most often the relative permeability is interpreted as the slope of the linear part of all of those graphs, although it does change as you apply a greater and greater field.
Magnetic hysteresis is a pretty fucked topic honestly, it took me a while to get it understood.
