Fleeting Light (流光): a playable chaotic reconstructive spectrometer

Fleeting Light (流光) is a single-file browser game about the physics of reconstructive spectrometers. The player places circular scatterers inside a leaky rectangular cavity to shape the dwell-time distribution of a handful of photons. The correspondence to the physics is exact rather than decorative: one photon = one sample of the dwell-time distribution p(t); the detector's N layers = the ideal distribution cut into N equal-probability blocks, each guarding one time window (narrow and crowded early, progressively wider later, because a leaky cavity's ideal distribution decays exponentially); stripping a layer = a photon arriving inside that window; the run fails the moment a window closes empty, i.e. the empirical distribution has a hole; the spectral resolution on the victory screen is not a preset target, but is inferred from the player's own arrival times via the spectral correlation C(Δν) = |FT{p(t)}|2. A consequence the game makes tangible: a regular array of scatterers almost always loses to a handful of circles dropped by hand, because symmetry collapses many optical paths onto the same length and p(t) falls into a few spikes. Chaos is not a side effect of the scheme; it is the working principle. The model is derived from the bounds established in Phys. Rev. Lett. 137, 123802 (2026). Runs entirely client-side with no dependencies: open index.html in any modern browser. Bilingual interface (English / 中文).