May 26, 2026 · 1 min read
What is a perfectly matched layer (PML)?
The absorbing boundary condition that makes finite-domain wave simulation possible: how it works, when it fails, and why integral equation methods do not need one.
Notes
Field notes from Planck Labs.
Technical writing on electromagnetic simulation, numerical methods, and computational physics.
May 19, 2026 · 1 min read
FDTD vs FEM vs MoM: a plain-English comparison
The three dominant families of numerical methods for electromagnetic simulation, what each is good at, and where each one breaks down.
May 12, 2026 · 1 min read
What is electromagnetic simulation?
An introduction to numerical solution of Maxwell's equations: what these solvers compute, where they are used, and the families of methods that dominate the field.
May 5, 2026 · 3 min read
Convergence order in electromagnetic simulation: why mesh refinement compounds
The order of accuracy of a numerical method is a structural property, not a tuning parameter. In three-dimensional wave problems, the difference between second-order and sixth-order convergence is the difference between needing 32× more degrees of freedom per decade of accuracy and needing 3×.