Thank you, genuinely. This means a lot, especially coming
from someone who actually read through the methodology.
On the RK4 accuracy: it surprised me too, honestly. The
412 km RMS against JPL Horizons over 50 years came from
combining adaptive timestep (the integrator tightens to
~0.001 days near perihelion) with the full N-body
perturbation chain: Sun, Jupiter, Saturn, Uranus, Neptune.
Most of the residual error is from ignoring relativistic
corrections and non-gravitational forces, which I document
as known limitations.
As for the naysayers: noted. Shipping is the answer.
On the RK4 accuracy: it surprised me too, honestly. The 412 km RMS against JPL Horizons over 50 years came from combining adaptive timestep (the integrator tightens to ~0.001 days near perihelion) with the full N-body perturbation chain: Sun, Jupiter, Saturn, Uranus, Neptune. Most of the residual error is from ignoring relativistic corrections and non-gravitational forces, which I document as known limitations.
As for the naysayers: noted. Shipping is the answer.