make-the-invisible-visible · autonomous run 000 · 2026-08-17 21:19

Reverse-Time Migration: 12 Million Cubic Meters

The acoustic scattering matrix of the 12 million cubic meters of WWII rubble directly dictated the atmospheric multipath propagation of intercepted Cold War telemetry; the physical ruins of the former conflict literally served as a passive dielectric lens for the latter.

Subterranean acoustic impedance maps back-propagated across Teufelsberg's radar domes. · motion: back-propagating acoustic reflections into the visible spectrum

wall text

Built atop 12 million cubic meters of WWII debris concealing the Wehrtechnische Fakultät, Teufelsberg operated as a premier Cold War signals interception site. This installation transposes Ambient Noise Tomography (ANT) and Reverse-Time Migration (RTM) into visual topology. By recording ambient urban microseisms across a distributed geophone array, cross-correlating signal noise extracts subterranean Green's functions. The resulting model traces acoustic impedance interfaces between loose brick rubble and reinforced concrete. Projected onto the surface radomes, these inverted wavefields treat the historical ruins as a passive scattering lens that physically structured electromagnetic surveillance over Berlin.

shown: Installed as a site-specific projection mapping event directly on the main Teufelsberg radome, visible from the Berlin Olympic Stadium, with live ambient seismic data feeding the visualization.

mechanism

Ambient Noise Tomography (ANT) — Placing 120 geophones around the base of Teufelsberg to record urban microseisms, treating the entire geological structure as a passive acoustic lens rather than a mere elevation for electromagnetic interception.
1. Deployment of a dense seismic array
Cross-correlation of ambient seismic noise — Computing the Green's functions between all geophone pairs to map the internal density gradients and void spaces, turning random urban vibrations into a coherent structural map.
2. Signal extraction of the rubble matrix
Reverse-Time Migration (RTM) — Running the seismic wave equations backward in time through a digital model to computationally focus and image the exact subsurface scattering interfaces where 1940s concrete meets loose broken brick.
3. Back-propagation of the acoustic wavefield
Laser Doppler Vibrometry — Projecting the calculated subsurface scattering matrix onto the decaying fabric of the listening station using scanning lasers, transforming the listening spheres into visual monitors for the ruins below.
4. Surface projection of the impedance map

lineage

Trevor Paglen, 'Limit Telephotography' — Expands Paglen's optical resolution limits into the acoustic subsurface mapping of state secrecy.
Susan Schuppli, 'Material Witness' — Validates her thesis by treating the 12 million cubic meters of rubble as an active, queryable recording medium.
Lawrence Abu Hamdan, 'Walled Unwalled' — Inverts his use of acoustic leakage by visualizing how solid terrestrial mass absorbs, refracts, and ultimately betrays historical trauma.

curatorial qa (machine verdict, unedited)

SCORE 3/5 after 2 attempt(s)
READS: Subsurface architectural wireframes overlaying Teufelsberg and the technical cross-correlation tomography artifact communicate the layering of WWII concrete beneath modern listening posts.
FAILS: The central green lightning flare reads as fantasy energy discharge rather than acoustic back-propagation or wavefield inversion mapping.

spec: antigravity agent · keyframe/artifact: gemini-3.1-flash-image · video: veo-3.1 image-to-video · qa+wall text: gemini-3.7-flash watching the render · 32.6s total