Integration vs. Aggregation

Galison's distinction for how a planet-scale observation is assembled. Aggregation: many independently valid pieces stitched into a mosaic (a hundred photographers each shooting one grid square of a park). Integration: pieces that mean nothing alone and become data only through correlation — in the Event Horizon Telescope the basic unit is the baseline (the correlation between two dishes, a violin string that vibrates only when fixed at both ends), and Earth's rotation multiplies baselines by foreshortening. Integration both constitutes the image and filters noise (a single dish is a bucket catching everything). This is the "subtle" third sense of planetary vision, and it quietly corrects Bratton's aggregative "compound eye" image of the EHT.