What the application covers, how to work it, and what to do when a number looks wrong.
The application opens on a working configuration — a module is already selected and a result is already computed. You do not have to create a document or pick anything first. Change an input and the outputs and plots update with it.
Every screen corresponds to one topic. The list on the left switches between them; on a narrow window the list becomes the first screen and a back control returns to it.
1.6e-19) and a leading
minus sign are all accepted.The unit system is a toolbar control, not a per-screen setting, because it is a property of how you read rather than of what you are computing. Switching it re-spells the numbers; it never changes the physical situation you set up.
A few quantities are not merely rescaled between the two systems — their definitions differ. Where that is the case the screen says so instead of presenting a bare conversion factor as if it were a simple change of units.
Where a relation has more than one physically distinct case — the two polarisations at an interface, acceleration along versus across the velocity, the good-conductor approximation versus the full expression, inside versus outside a boundary — the choice appears on screen as a control you set. The application never picks one silently. This is deliberate: a quietly chosen branch is the easiest way for a correct calculator to hand you a wrong answer.
Profiles are plotted against position or angle, with axes labelled in the unit system currently selected. Where a quantity is genuinely discontinuous at a boundary, the curve breaks there; it does not draw a vertical line across the jump.
Plots export as images and result tables as CSV, through the system share sheet. CSV files are written to the comma-separated convention, with fields quoted whenever their contents would otherwise be ambiguous — including when a field contains a carriage return, which is the case that silently corrupts most hand-written CSV writers.
Included: linear, isotropic, homogeneous media; closed-form and series solutions.
Not included: numerical field solvers, meshing or finite-element methods; material property tables; non-linear, anisotropic or inhomogeneous media; quantum electrodynamics.
These are boundaries of the product, not defects. If you need a numerical field solution on an arbitrary geometry, this is the wrong tool and no future version is planned to become the right one.
The relations in this application are covered by an automated test suite, and it is worth being exact about what that suite does, because it is not the usual arrangement.
The theory this application implements is developed symbolically in its source material: it derives relations and prints very few worked numerical examples. There is therefore no large published answer table to check against, and this application does not claim one exists.
What is checked instead is each relation against its own structure: limiting cases, symmetry, conservation and orthogonality identities, agreement between independently derived forms of the same quantity, and round-trips through the unit conversion. Where two independent treatments of the same physics both cover a result, they are cross-checked against each other.
Those checks are strong against algebraic errors, sign errors and transcription errors. They cannot prove a relation was read correctly off the page to begin with. That limit is stated here rather than left for you to find.
Please report it, and if you can, include:
The fourth item is the one that matters most. A disagreement between this application and a source is worth chasing in either direction, and it cannot be chased at all without knowing what it is being compared to.
The application runs on Mac and iPad. It requires no network connection, because it never uses one — it works identically on a plane, in an exam hall, or in a basement laboratory.
Write to the address on the App Store listing for this application. There is no account system and no login; nothing about your copy needs to be recovered or transferred.