{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp05_complete_proposal_portfolio20_20260803","cell_id":"negative_space_design__astronomy_astrophysics","arm":"COMPLETE_PROPOSAL_PORTFOLIO","candidate_id":"nsd-astro-blank-sky-witness-lattice","proposal_index":5,"version":0,"title":"Blank-Sky Witness Lattice for Multiplexed Spectroscopy","problem":"A multiplexed spectroscopic configuration can assign nearly every available aperture to a celestial target, leaving the background inferred from separate exposures, distant samples, or a small and spatially uneven set of target-free channels. If atmospheric emission, scattered light, detector response, or other background structure varies across the exposure or focal plane, subtraction residuals can resemble, obscure, or alter faint spectral features in target channels.","actors":["Astronomers designing multiplexed spectroscopic configurations","Instrument and observatory scientists","Spectroscopic reduction-pipeline developers","Investigators whose targets compete for apertures","Data-quality and calibration reviewers"],"observable_state":"Configuration and exposure records can show which apertures contain intended targets, which sample target-free lines of sight, their distribution across focal-plane and detector coordinates, their throughput and contamination status, the background model fitted from them, residual structure in held-out witness spectra, and the target assignments omitted or deferred to create the lattice.","consequence":"Background structure may remain entangled with faint target features, while reviewers lack simultaneous target-free measurements distributed across the same instrumental configuration with which to test the subtraction.","affected_objective":"Separate faint celestial target spectra from contemporaneous atmospheric and instrumental background while making the scientific opportunity cost and validity of the background samples auditable.","intervention":"Design each eligible multiplexed configuration with a protected lattice of target-free witness apertures distributed across relevant focal-plane and detector regions. Each witness points to a location with no intended source inside a declared exclusion boundary under the configuration's input catalog and acquisition checks. Witness apertures are protected from late target assignment after configuration lock and collect spectra simultaneously with target apertures. Their absence of an intended target makes local sky and instrumental structure observable. Channel-throughput tests distinguish a valid witness spectrum from a dead or failed aperture, and post-exposure checks reclassify witnesses contaminated by uncatalogued sources, cross-talk, or acquisition error. A declared subset fits the background model while separate witnesses remain held out to test subtraction. Targets omitted from witness positions remain recorded and eligible for later configurations rather than being deleted.","structural_mapping":[{"archetype_element":"Attention Competition Map","domain_realization":"Map pressure to maximize target count against the need to observe background variation across focal-plane, detector, and wavelength regions."},{"archetype_element":"Omission Candidate","domain_realization":"Identify target assignments that can be deferred from selected apertures without violating mandatory calibration, priority, cadence, or configuration constraints."},{"archetype_element":"Protected Empty Space","domain_realization":"Reserve lines of sight containing no intended target so their spectra can serve as simultaneous background witnesses."},{"archetype_element":"Positive Form Relationship","domain_realization":"The target absence in witness apertures makes the background component measurable, thereby clarifying which structures in neighboring target spectra remain after subtraction."},{"archetype_element":"Absence Boundary","domain_realization":"Define each witness through a source-exclusion region, catalog threshold, acquisition check, detector assignment, and configuration-lock rule."},{"archetype_element":"Context Preservation Frame","domain_realization":"Retain aperture throughput, coordinates, source-catalog limits, exposure conditions, detector mapping, target opportunity cost, and contamination flags alongside each witness."},{"archetype_element":"Meaning-of-Absence Check","domain_realization":"Distinguish an intentionally target-free spectrum from a dead channel, failed exposure, acquisition miss, catalog omission, or contaminated line of sight."},{"archetype_element":"Reintroduction Trigger","domain_realization":"Reclassify a witness as object-bearing and exclude it from the background model when post-exposure evidence reveals a source; return deferred targets to the eligible pool for later configurations."},{"archetype_element":"Accessibility and Recoverability Guardrail","domain_realization":"Preserve raw witness spectra, rejection reasons, omitted-target records, and alternative reductions so neither calibration evidence nor target cost is hidden."},{"archetype_element":"Clarity or Effect Test","domain_realization":"Use held-out witness apertures to test whether the fitted background accounts for spatial and detector variation without evaluating the model only on spectra used to fit it."}],"mechanism_mapping":[{"mechanism_slug":"architectural_void","role":"Designs the target assignments and target-free apertures as one figure-ground configuration, sizes and distributes the voids from the occupied apertures inward, and protects them against later infill.","counterfactual_removal":"Without this mechanism, target-free apertures become incidental leftovers that may cluster in unrepresentative regions or disappear when another target can be assigned."},{"mechanism_slug":"editorial_cut","role":"Defers only target assignments compatible with the witness plan, preserves their priority and constraints, and keeps them recoverable for a later configuration.","counterfactual_removal":"Without this mechanism, creating the lattice could arbitrarily discard science targets or conceal the observational cost of the calibration samples."},{"mechanism_slug":"empty_state_design","role":"Diagnoses each apparently empty channel as intentional blank sky, instrument failure, acquisition error, or source contamination before it is admitted to the background model.","counterfactual_removal":"Without this mechanism, a failed or contaminated aperture could be treated as a valid expression of the background merely because no intended target was assigned."}],"causal_chain":["Configuration design identifies focal-plane and detector regions over which background behavior needs simultaneous constraint.","Selected apertures are left without intended celestial targets and protected from target infill.","Because the witnesses share the target exposure, they record contemporaneous atmospheric and instrumental contributions under the same configuration.","Spatial and detector distribution lets the reduction model test whether those contributions vary across the multiplexed field.","Throughput and contamination checks remove channels whose apparent emptiness has the wrong cause.","One witness subset fits the background while held-out witnesses test the resulting subtraction independently.","Target spectra can then be assessed against an explicitly measured and validated background estimate, with the deferred-target cost retained for allocation review."],"baseline":"Configuration software prioritizes feasible target assignments, while background subtraction relies on whatever target-free apertures remain, separate sky exposures, or a reduction model estimated from the ensemble of observed spectra.","nearest_rivals":["Separate offset-sky exposures obtained before or after the target exposure","Nodding targets between object and sky positions through the same apertures","A robust background model inferred from the multiplexed target spectra without protected target-free witnesses","A small fixed set of dedicated sky apertures without explicit spatial distribution or held-out validation"],"remaining_contrastive_claim":"The proposal's defining move is to use the absence of an intended target as a protected, distributed, simultaneous measurement condition. Unlike an offset exposure, the witnesses share the target exposure; unlike nodding, they do not alternate target and sky; unlike ensemble modeling, they supply spectra whose interpretation does not begin with target removal. The bounded question is whether the designed lattice constrains or tests background structure beyond these rivals at an acceptable recorded target cost.","authority_safety":{"decision_authority":"The instrument scientist and configuration lead may design a shadow lattice under existing time-allocation and calibration policies. Any prospective use that displaces approved targets requires authorization from the observatory's established allocation authority.","authorized_first_step":"Perform a read-only retrospective evaluation using archived configurations that already contain independently documented target-free apertures; do not modify a live configuration, target allocation, raw exposure, production reduction, or scientific result.","excluded_actions":["Removing mandatory calibration, alignment, safety, or high-priority target assignments","Claiming that a witness is astrophysically empty beyond the declared catalog and acquisition limits","Treating a dead, low-throughput, contaminated, or mispositioned aperture as valid blank sky","Changing source-exclusion or rejection rules after viewing a desired spectral feature","Overwriting raw spectra or production background models","Using retrospective pilot reductions in catalogs, publications, or observing decisions without separate authorization","Hiding the identities and opportunity costs of deferred targets"],"halt_rollback":"Stop if archived data lack independently documented target-free apertures, throughput information, detector mapping, or contamination checks sufficient to distinguish intentional blank sky from channel failure. Also stop if shadow configurations would require violating mandatory target or calibration constraints. Rollback consists of discarding derived shadow configurations and reductions while retaining all archived observations and production products unchanged."},"negative_tests":{"strongest_counterevidence":"Offset-sky, nodding, or robust ensemble methods leave equal or smaller held-out background residuals without sacrificing multiplexed targets, while protected witnesses are contaminated, spatially unrepresentative, or too sparse to constrain the relevant variation.","problem_falsifier":"The inferred problem is falsified for the tested instrument and regime if background residuals are not associated with spatial, detector, or exposure-dependent variation that simultaneous target-free samples could observe, or if the existing calibration design already provides adequate independent coverage and validation.","intervention_falsifier":"The intervention is falsified if lattice-based models do not improve prediction on held-out target-free apertures relative to the strongest rival, do not change the stability of faint-feature interpretation under alternative valid reductions, or impose a target-allocation cost rejected by the authorized allocation body.","risks":["Uncatalogued or diffuse sources may contaminate locations classified as blank.","Reserving apertures reduces the number of simultaneous science targets.","Witness placement constraints may produce a lattice unrepresentative of target locations or detector behavior.","Cross-talk from bright neighboring targets may enter nominally blank channels.","Atmospheric variation may occur on scales the lattice cannot resolve.","Catalog thresholds and exclusion radii may bias witnesses toward unusual field environments.","Held-out witnesses may be too few to separate background-model error from channel-specific noise.","Deferred targets may not remain observable in a later configuration despite being retained in the queue."]},"next_evidence_step":"Identify no more than six archived multiplexed spectroscopic configurations containing raw data, detector and throughput metadata, target assignments, and enough independently labeled target-free apertures to form fitting and held-out subsets. If that condition is unmet, stop. Freeze wavelength calibration, masks, rejection rules, and source-exclusion criteria. Compare the production background method, the strongest feasible rival, and prespecified shadow lattices that vary only in witness distribution and count. Evaluate residual continuum and line structure on held-out witnesses, the stability of selected faint target features across valid reductions, contamination detection, and the target assignments a corresponding shadow configuration would defer. Use the results only to determine whether a separately authorized prospective configuration test is warranted.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Proposal 1 leaves future telescope time unassigned so late transient information can activate it. Proposal 5 instead points selected simultaneous apertures at lines of sight with no intended targets so those apertures actively measure background; they are not waiting for future targets and are not released during the exposure. Proposal 2 removes interface annotations from valid image pixels to prevent graphical occlusion. Proposal 5 changes the physical observing configuration and collects additional calibration spectra; it does not alter image presentation or hide overlays. Proposal 3 protects conversational silence before anomaly discussion to reduce first-speaker framing. Proposal 5 has no facilitation or hypothesis-generation procedure; its causal path runs from target absence to direct background measurement and subtraction validation. Proposal 4 uses blank spans in a time-series graphic to denote the absence of usable measurement and prevent implied continuity. In proposal 5, the nominally blank aperture produces a usable measurement precisely because an intended celestial target is absent. Its problem, intervention, evidence object, causal path, actors, and adoption unit are therefore distinct from all four earlier proposals.","revision_record":{"parent_version":null,"progress_targets_addressed":["Fifth independently adoptable proposal","Explicit diversity from proposals 1 through 4","Physical observational use of target absence","Auditable target-allocation cost and contamination safeguards","Held-out validation and bounded first evidence"],"conceptual_changes":[],"operational_changes":[],"evidence_changes":[],"claim_changes":[]}}