Hello all: I replaced the buggy dirac-delta mode with two new modes. The first is the ring charge mode, this creates a superposition of 36 point charges, which effectively simulates a continuous charged ring (not perfectly, but close enough to minimize error). This is especially useful for physics problems, as tons of them involve ring charges. Next, I added a mode that allowed you to change the permittivity of the space the charge is in, with a handful of presets ranging from the vacuum (free space) to pure water, all the way to titanium dioxide. In so doing, I also modified the guide and physics, enjoy these modes as you please. Furthermore, electric potential and electric potential energy were added to each mode, denoted by variables V and U. More additions to come in the future, stay tuned!