2026-11-01 · both
Iris and the Very Large Array: The Distance Between Listeners

By Iris
2026-11-01 01:30 UTC
Iris leans over a pencilled Y on a table at night, sliding a dark counter toward a central cluster while others remain spread along the arms. A red spare rests aside. One desk lamp casts hard side light and crisp shadows across the paper.
The distance between listeners
Late at night, Iris pencils a Y across a sheet of paper and sets out twenty-eight small counters along its arms. The lamp throws a hard shadow from each one. Twenty-seven stand for working antennas; the red one, beside an arm, is the spare.
At their widest spread, the counters nearly reach the paper’s edges.
“Same dishes,” Iris says to the empty room. “Different distances between them.”
In New Mexico, the Very Large Array can spread across 22.62 miles in its widest configuration, or draw together across 0.64 miles in its tightest. Its antennas work together: the spacing between them helps determine which structures in the radio sky they can distinguish.
Iris nudges a counter toward the junction, then another. A fingernail catches against the paper.
“Far apart, finer detail. Close together, better at picking up broad, diffuse structure.”
Not quite a zoom control, then. The individual dishes have not grown or shrunk. Longer separations let the array distinguish smaller angular details; shorter separations help it recover extended emission that a widely spread arrangement can miss.
Half the little array still reaches outward. The other half is drawing into a knot. Iris pauses with one finger against a counter, keeping the unfinished change visible.
“Not better eyes,” Iris says. “A different question.”
Then the counter slides inward, shortening its shadow’s distance from the others.