At least some of the disputed pre-Sputnik plate marks were produced by light entering the telescope during the original exposure, rather than being introduced afterwards in the emulsion, the copying chain, or digitization.

The crux. Copy-defect mechanism and artifact morphology on one side; flash physics and unvalidated coma signatures on the other; the original negatives — the decisive witnesses — remain unexamined.

Whether marks on the plates represent actual incident light is the unresolved crux of the entire case. While some Hamburg marks show preliminary coma aberrations suggesting real light, the strongest opposing consideration is that the Palomar marks fall into known artifact morphologies and their original negatives have never been inspected to rule out copying flaws.

Evidence against real incident light includes the sharp, concentrated morphology of the 1950 nine, which lies in the region where the Hambly & Blair classifier places spurious detections, and their reconstruction of a copy-stage pathway that could create such defects in both digitizations (TRN-E003–E005). In favour of incident light are the physical reality of the marks, their repeated occurrence in multi-source configurations (TRN-E001, TRN-E007), the plausible physics that genuine sub-second flashes should also be unusually sharp (TRN-E006), and the Hamburg coma results suggesting some independent candidates carry an optical-aberration signature (TRN-E014). However, there has been no blinded inspection of the original Palomar negatives (TRN-R001), no experimental calibration of flash versus artifact profiles (TRN-R002), and no blind validation of the coma discriminant (TRN-R003). Given these gaps and the existence of a concrete but unquantified copy-defect mechanism, the balance of evidence neither establishes nor rules out real incident light. The strongest opposing consideration to “no light” is exactly the Hamburg coma line, which, if validated, would directly support this claim for at least some events.

This is the genuine crux, and the decisive measurement has not been made. Against incident light stand artifact-like sharpness, a concrete copy-defect pathway, Hambly and Blair's morphology classifier, and the GRB-era record of star-like impostors; for it stand an uncalibrated flash-physics argument and Hamburg candidates, outside the Palomar copy lineage, that reportedly carry coma. The strongest opposing consideration is that Hambly and Blair inspected the actual glass, found the canonical marks grouped with artifacts on plates that visibly carry emulsion holes and copy blemishes, and showed both digitizations descend from a shared ancestor.

This is the crux, and the record is genuinely two-sided. For incident light: the sharpness of the 1950 nine matches what sub-second flash physics predicts (TRN-E006), the classifier condemning them was trained on a "spurious" class defined by lacking a modern counterpart — the very property defining transients — and Hamburg candidates outside the Palomar genealogy reportedly carry coma signatures (TRN-C011). Against: all nine marks sit in the morphological neighborhood of known spurious detections, both digitizations descend from a shared intermediate positive where a single defect could enter every dataset (TRN-C007), and the plates visibly carry emulsion holes and copy blemishes. The decisive observation — blind high-resolution examination of the original telescope negatives — has never been made, and no ensemble statistic can substitute for it. High confidence that the record as it stands cannot settle this rung.

This is the crux and it is genuinely open in the file's own terms: against it, the canonical nine group morphologically with spurious detections and a concrete shared-copy-stage pathway exists; for it, sub-second flashes are independently expected to be sharp, the classifier's "spurious" label is defined by the very property that defines a transient candidate, and the Hamburg coma report describes a signature outside the Palomar copy lineage. Neither side has a calibrated discriminant: no flash-profile curve on period emulsion, no measured copy-stage defect rate, no blind coma validation, and no examination of the original negatives. The strongest opposing consideration is that the mundane branch has a proven mechanism and an ugly historical track record while the exotic branch has only arguments and one unblinded preprint — so if forced to bet I would bet artifact, but that is a prior, not a finding, and I choose "unresolved" over "mixed" because the opposing evidence bodies are each too weakly diagnostic to constitute a real split.

Materially narrowed but not settled: TRN-E022 excludes the copying-chain and digitization branches for the canonical events, but the intrinsic-emulsion-defect branch survives and TRN-E024 shows microscopy cannot close it — with the inspecting microscopist leaning defect. The question is now 'flash or flaw in the original emulsion,' which single-source morphology cannot answer.

The crux is untouched: copy-defect pathway (TRN-C007) and artifact morphology (TRN-E004) against flash physics (TRN-E006) and unvalidated coma signatures (TRN-E014). TRN-E021 assumes this claim rather than testing it, so it adds nothing; the original negatives remain unexamined.

The crux. Copy-defect pathway (TRN-E005) and artifact morphology (TRN-E004) against flash physics (TRN-E006) and unvalidated coma signatures (TRN-E014); the decisive witnesses — the original telescope negatives — remain unexamined.

The crux is unchanged: copy-defect pathway (TRN-C007) and artifact morphology (TRN-E004) against flash physics (TRN-E006) and unvalidated coma signatures (TRN-E014). The original negatives — the only witnesses above the shared copy stage — remain unexamined.

This is the critical physical crux of the entire case: were the marks made by incident photons or by chemistry? While recent unpublished microscopy places the canonical 1950 marks on the original telescope negative—ruling out the specific intermediate-copy-defect pathway for those events—the microscopist noted they strongly resemble emulsion defects, and the manuscript itself admits that microscopy cannot definitively distinguish a sub-second flash from a chemical flaw. The strongest opposing consideration is the historical failure of similar archival searches, which routinely found that sharp, star-like transient candidates ultimately dissolved into emulsion defects, development spots, or handling damage under rigorous scrutiny.

Arguments for incident light rely on sub-second flash physics and preliminary coma aberration signatures, while arguments for plate artifacts cite morphological classification and a shared copying genealogy. Because the original telescope negatives have not yet been blindly examined to rule out copy-stage defects, the claim cannot be resolved in either direction. The strongest opposing consideration to real light is the established shared-ancestor copying pathway that can mint defects mimicking unique sources.

There is credible evidence both ways. Against: Hambly & Blair show that all nine 1950 marks are in the sharp, artifact-like tail of the profile distribution and are classified morphologically with spurious detections (TRN-E003, TRN-E004), and a well-documented copy-genealogy allows defects to propagate into both main digitizations (TRN-E005). For: Yang & Villarroel establish that the 1950 nine are present on the original negative, removing copy-only defects for those events (TRN-E022, TRN-E023), and Hamburg candidates show coma-like PSFs consistent with light through the optics (TRN-E014). Yet the microscopy manuscript explicitly concedes that individual point-like features on the original cannot be distinguished between flash and emulsion defect, and its microscopist leans toward defects (TRN-E024). The strongest opposing consideration is this explicit, expert statement that the decisive test envisioned for decades cannot classify these marks, leaving the crux genuinely unresolved.

There is substantial, structured evidence on both sides. Against: the 1950 nine have morphologies sharply distinct from stars but grouped with known artifacts in SuperCOSMOS (TRN-C002, TRN-E003–E004), the plates show a rich defect population on inspection (TRN-E002), and a well-documented copy-genealogy provides a mechanism for star-like defects to enter both digitizations without being on the original negative (TRN-C007, TRN-E005). For: physics predicts sub-second flashes should also look sharp (TRN-C102, TRN-E006), a second canonical multi-source event exists (TRN-C003, TRN-E007), analogous candidates are reported from an independent observatory (TRN-C010, TRN-E013), and coma-like signatures in Hamburg candidates suggest passage through telescope optics (TRN-C011, TRN-E014). The strongest opposing consideration is that no canonical mark has yet been shown, via blinded, generation-resolved examination, to be present on an original negative with an optical signature that excludes plate and copy defects.

This is the gate, and the 2026 microscopy narrowed it without opening it. The April 1950 nine sit on the original Caltech glass and the 1952 triple is not confined to copy material (TRN-E022, TRN-E023), which retires the shared-ancestor pathway for the flagship events; Hamburg candidates lie outside that pathway altogether and are reported to carry coma (TRN-E014). Against that, Hambly and Blair's classifier groups the Palomar marks with artifacts (TRN-E004), the independent microscopist directed to the nine objects judged emulsion defects reasonable (TRN-E024), and the manuscript itself states that single-source microscopy cannot split a sub-second flash from a flaw born in the emulsion. The strongest opposing consideration is that the only physical discriminant on the table — coma — is a single-author, unblinded preprint that the author says does not establish origin.

Against incident light, the 1950 marks sit in the SuperCOSMOS sharp tail that Hambly and Blair's classifier groups with artifacts, a shared intermediate-positive pathway can print one flaw into both modern digitizations, and two decades of GRB plate searches never confidently confirmed an archival optical transient. For incident light, sub-second flashes are expected to be sharp, and Hamburg plates lie outside the Palomar copy genealogy and reportedly show analogous candidates carrying coma. Neither side has the decisive datum — blinded high-resolution inspection of the original telescope negatives — and flash-versus-artifact profile distributions have never been calibrated on period emulsions. Strongest opposing consideration: Hambly and Blair inspected the surviving glass, found the canonical marks morphologically grouped with artifacts amid visible emulsion holes and copy blemishes, and showed both digitizations are cousins rather than independent witnesses.

This is the crux, and the 2026-08-24 microscopy results (E022–E024) narrow it without settling it: the nine 1950 marks are reported on the original telescope negative — retiring the shared-copy-stage mechanism (E005) for the flagship events — yet the manuscript itself concedes microscopy cannot distinguish a sub-second flash from an intrinsic emulsion defect, and its own Hambly-directed microscopist leaned defect. The sharpness observation (E003) points both ways pending the calibration experiment that has never been run (E006). The strongest positive line is the Hamburg coma signature (E014), a physical incident-light discriminant on an independent plate lineage, but it is single-author, unblinded, and unvalidated against defect mimics. The strongest opposing consideration is the classifier result (E004), weakened by a real circularity — its "spurious" training class is defined by exactly the absence-of-counterpart property that defines transients. With the seventy-five-year test now exhausted and the remaining ones unrun, unresolved is the only honest grade.

This is the crux, and the evidence genuinely splits. Against incident light: all nine canonical marks fall in the classifier's artifact morphological neighborhood, both digitizations descend from a shared copy stage where one defect could enter every modern dataset, and the GRB-era archival searches supply a sobering prior on star-like plate marks (a background-rate calibration, noted as prior rather than record evidence). For incident light: sub-second flash physics predicts exactly the observed sharpness, the skeptical classifier is arguably trained to label any real transient as artifact by construction, the copy-defect mechanism has a demonstrated pathway but an unmeasured occurrence rate, and the Hamburg coma report is a real physical discriminant that chemistry should not trivially mimic — though it is a single unblinded preprint. The strongest opposing consideration to "real light" is the morphology-plus-genealogy combination; the strongest opposing consideration to "artifact" is that the mundane mechanism's base rate has never been measured and the coma line is untouched by it. With the decisive blind examination of the original negatives never performed under a public protocol, unresolved is the honest verdict.

The evidence is close to symmetrically balanced and the file documents why. Against: the marks group morphologically with unmatched detections (TRN-E004), sit in a plate corner where defects congregate, and the GRB-era archival record is a long list of star-like impostors; an experienced microscopist looking at the original glass called emulsion defects a reasonable attribution (TRN-E024). For: sharpness is exactly what a sub-second flash should produce (TRN-E006), the digitization and copy-stage pathways are now excluded for the flagship events (TRN-E022), and a coma signature has been reported outside the Palomar lineage (TRN-E014). The strongest opposing consideration to any positive verdict is TRN-E024's own admission that microscopy cannot separate flash from intrinsic emulsion defect at the single-source level, which means the observation everyone waited for returned a null on the actual question.

This is the case's crux and it is genuinely open: against it, the canonical nine group morphologically with spurious detections (TRN-E004) and a shared-copy-stage pathway can print one flaw into both digitizations (TRN-E005); for it, sub-second flashes are also expected to be sharp (TRN-E006, an argument not a measurement), and the Hamburg coma report (TRN-E014) would, if validated, indicate light through the optics. The strongest opposing consideration is that the artifact side is not merely a possibility argument — the GRB-era archival record shows star-like defects are common and confirmed archival transients are not — which makes the mundane branch the higher-prior one even though it has never been demonstrated for these specific marks. The decisive measurement (blinded examination of the originals, generation of first appearance) remains unreported in this file; a proponent microscopy manuscript is mentioned but has not been seen and cannot count.

TRN-E022 removes digitization and the copy chain as origins for the nine 1950 marks, but the remaining disjunct — a defect in the original emulsion — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it. The crux moved up one layer without closing.

TRN-E022 eliminates digitization and the copying chain as origins for the nine 1950 marks — a genuine narrowing — but the claim's remaining disjunct, defect in the original emulsion, is exactly where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide flash versus flaw. The crux has moved up one layer without resolving.

TRN-E022 removes digitization and the copy chain as origins for the nine 1950 marks, but the remaining disjunct — a defect in the original emulsion — is precisely where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it. The crux has moved up one layer without closing.

TRN-E022 removes digitization and the copy chain as origins for the nine 1950 marks, but the remaining disjunct — a defect in the original emulsion — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it. The crux moved up one layer without closing.

Unpublished microscopy confirms the canonical marks are present on the original negatives, ruling out digitization artifacts, but also concedes that microscopy cannot distinguish between a short-duration flash and an original emulsion defect. The strongest opposing consideration is that the canonical marks morphologically group with known artifact classes, and independent visual inspection leaned toward emulsion defects.

There is real tension here. On one side, Yale & Villarroel’s microscopy shows the canonical 1950 marks on the original negative (TRN‑E022), and independent Hamburg candidates with coma-like signatures (TRN‑E014) suggest incident light through a different telescope, both favoring real flashes. On the other, Hambly & Blair’s morphology and classifier group the 1950 nine with known artifacts (TRN‑E003, TRN‑E004), the microscopist on the original plate leans toward emulsion defects (TRN‑E024), and the copy-genealogy plus GRB archival experience (TRN‑C101) show a rich defect ecology. The strongest opposing consideration is that no blinded, physically grounded discriminant between flash and defect (e.g., calibrated profiles, validated coma test) has yet been applied; morphology and statistics alone cannot decisively assign origin to any individual mark.

This is the gate the rest of the ladder depends on, and it has not been walked through. Presence of the 1950 nine on the original Caltech glass (TRN-E022) would retire scanner and copy-stage origins for that event if the unpublished registration holds, and Hamburg candidates plus a reported coma signature (TRN-E013, TRN-E014) sit outside the Palomar copy lineage entirely; but the same microscopy manuscript states that a brief flash and an emulsion defect produce the same sharp little dot, and its own microscopist — sent to the objects by Hambly — leaned defect. Hambly’s morphology classifier groups the nine with artifacts, the GRB-era searches never confirmed an archival optical transient, and the coma discriminant has not been blind-validated. The strongest opposing consideration is that every positive indicator is either direction-ambiguous (sharpness) or preliminary (Hamburg/coma), while the one test this case waited seventy-five years for explicitly cannot finish the job.

The crux, and honestly open after the microscopy manuscript narrowed it. For light: the nine 1950 marks are now reported on the original negative (TRN-E022), retiring the copy-defect pathway for the flagship events; sub-second flashes are physically expected to be sharp (TRN-E006); and the Hamburg coma signature (TRN-C011) is in principle a physical incident-light detector. For chemistry: the marks sit in the exact morphological neighborhood of spurious detections (TRN-E003/E004); the manuscript's own microscopist leaned emulsion defect; the field lies in a defect-prone plate corner; and the manuscript itself states single-source microscopy cannot separate flash from flaw (TRN-E024). The strongest opposing consideration to a "flash" reading is the GRB-era base rate: decades of archival transient searches produced star-like defects routinely and zero confident archival flashes, a prior that must be paid down with calibration (TRN-R002) and blind discriminant validation (TRN-R003), neither of which exists. The strongest consideration against the defect reading is that nine simultaneous sharp points in ten arcminutes, absent forever after, is an unusual defect pattern — but "unusual" is not "impossible," and no measured defect rate exists to convert that discomfort into a likelihood. Unresolved.

This is a genuine standoff, not a default. Against: the marks group morphologically with spurious detections (TRN-E004, though its "spurious" training class is defined by the very property that defines a transient candidate, a circularity the record itself flags), plate archives are known to manufacture star-like marks at contaminating rates, and the microscopist who examined the original Caltech glass — directed there by the copy-defect argument's own author — judged emulsion defects a reasonable attribution. For: a sub-second flash is expected to be sharp (TRN-E006, an argument not a measurement), the Hamburg candidates lie outside the Palomar copy lineage, and the coma-aberration signature would, if validated, be a physical incident-light detector. The new microscopy (TRN-E022) removes the copy-chain and digitization branches for the flagship events but, by its own authors' account, cannot separate flash from original-emulsion defect — so the mundane space contracted without emptying, and the decisive calibration (TRN-R002) and blind coma validation (TRN-R003) remain undone.

TRN-E022 removes digitization and the copy chain as origins for the nine 1950 marks, but the remaining disjunct — a defect in the original emulsion — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it. The crux moved up one layer without closing.

Recent microscopy confirms the canonical marks are present on the original negatives (TRN-E022), eliminating scanner and copy-stage errors for those events. However, microscopy cannot distinguish a sub-second flash from a chemical emulsion defect, and the independent microscopist leaned toward defect (TRN-E024). The strongest opposing consideration is that automated morphological classifiers explicitly group these sharp marks with spurious emulsion artifacts (TRN-E004), leaving the physical origin of the marks entirely ambiguous.

Yang & Villarroel’s microscopy (TRN-E022) confirms that the nine 1950 sources (and the 1952 triple via copy plus original digitization) are on or directly tied to the original telescope negative, ruling out scanner artifacts and copy-only defects for these events. However, Hambly & Blair’s morphology and classification work shows that the sources fall in the same sharp-profile regime as known artifacts (TRN-E003, TRN-E004), and the independent microscopist cited in TRN-E024 finds an emulsion-defect attribution reasonable. The proponents’ physics argument that real sub-second flashes should also be sharp (TRN-E006) leaves sharpness ambiguous, and no experiment has yet calibrated flash profiles on period emulsions (TRN-R002), while coma-based incident-light evidence from Hamburg (TRN-E014) remains provisional. Thus there is meaningful evidence both for and against real sky photons at the time of exposure, and none is decisive.

Presence of the 1950 nine on the original Caltech negative eliminates scanner and copy-stage explanations for the flagship event, and Busko's reported coma pattern on Hamburg candidates is a physical discriminant chemistry should not naturally produce — but that discriminant is a single unvalidated preprint, and the Yang manuscript states that microscopy cannot separate a short flash from an intrinsic emulsion defect. Against the light reading, Hambly & Blair's classifier groups the marks with artifacts, the inspecting microscopist judged defects reasonable, and the GRB-era archival campaign never confirmed one plate transient. Strongest opposing consideration: sharpness plus a plate-corner location is exactly the morphological and spatial neighborhood of known defects, and no flash-profile calibration exists to break that degeneracy.

This is the crux, and unresolved is a finding, not a hedge. Against incident light: the classifier groups the nine with artifacts (TRN-E004), the manuscript's own microscopist leaned emulsion defect and flagged the plate-corner location (TRN-E024), and the GRB-era archival record shows star-like defects are routine while confirmed archival transients are nonexistent. For incident light: the sharpness is what uncalibrated flash physics predicts (TRN-E006), the copy chain is now reportedly excluded for both flagship events (TRN-E022, TRN-E023), and Hamburg candidates on an untouched lineage reportedly carry coma signatures (TRN-E014). The strongest opposing consideration to a "real flashes" verdict is that neither side has a measured rate — no copy-defect census, no flash calibration curve — so both mechanisms are unfalsified possibilities; the strongest against an "artifact" verdict is that the coma discriminant, if blind-validated, is a physical light detector. Neither decisive observation has been made.

This is the crux and it is genuinely open, but the openness has changed shape: TRN-E022 and TRN-E023 remove the digitization and copy-chain routes for the two canonical events, while TRN-E024 — reported by the proponents against their own interest — establishes that microscopy cannot separate a sub-second flash from an intrinsic emulsion defect, and that the examining microscopist leaned defect. Against reality: TRN-E004's classifier groups the marks with artifacts (though its "spurious" training class is defined by the very property that defines candidates, a real circularity), TRN-E011 states plainly that no feature in these datasets has been shown to be an optical transient, and the GRB-era base rate is unfavourable. For reality: TRN-E006's sharpness physics is coherent but uncalibrated, and TRN-E014's coma signature is the only physical incident-light discriminant on the table and is unvalidated. A pedantic reading should be flagged: over ~10⁵ rows, and given Watters' finding that ≥91% of ensemble features came from a set removed for lying within 5″ of catalog stars, "at least some marks were made by incident light" is nearly trivially true in an uninteresting way; I grade the intended sense — that genuine appear-once candidates record light through the telescope — and that is unresolved.

TRN-E022 eliminates digitization and copying as origins for the 1950 marks, but the surviving alternative — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and the manuscript itself concedes single-source morphology cannot decide it.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — a defect in the original emulsion — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide between flash and flaw.

TRN-E022 removes digitization and copy-stage origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide between flash and flaw.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — a defect in the original emulsion — is precisely where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide between flash and flaw.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide between flash and flaw.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it.

This is the true crux of the case. While the marks are confirmed to exist on the original emulsion, the authors' own microscopy admits that a sub-second flash and an intrinsic emulsion defect produce indistinguishable single-source signatures. The coma aberration findings in Hamburg plates offer a potential path forward but lack blind validation against known directional plate defects.

For: the canonical marks are real emulsion features, with unusual sharpness consistent with sub-second flashes, and Hamburg candidates reportedly carry coma patterns characteristic of light through the optics (TRN-C011), which, if confirmed, would directly support incident light. Against: Hambly & Blair’s classifier groups the 1950 nine with known artifact morphology, the plates show a rich defect population, and the microscopist quoted by Yang & Villarroel judged the 1950 features consistent with emulsion defects, noting their plate-corner location. Crucially, the coma result is a single unvalidated preprint, and the microscopy authors themselves state that individual features cannot be classified as flash vs defect on morphology. The strongest opposing consideration is thus that all currently discriminating tools (sharpness, microscope appearance) are known to be shared by defects, and the only new physical discriminant (coma) has not yet passed blind validation.

This is the crux and it remains open. Presence of the 1950 nine on the original negative, if the unpublished registration holds, closes the copy-stage escape for that event without telling flash from emulsion flaw; Hamburg coma is the only proposed physical discriminant and has not been blind-validated; sharpness is expected both for sub-second flashes and for artifacts. The strongest opposing consideration is the combination of Hambly and Blair's morphology classifier, the GRB-search defect bestiary, and the Caltech microscopist's defect-leaning opinion on the very plate that was supposed to settle the question.

Genuinely open, and now precisely located: after TRN-E022/E024 the question is no longer "original or copy" but "flash or flaw in the original emulsion," and the manuscript itself states single-source microscopy cannot answer that. For incident light: sub-second flashes should be sharper than trailed stars (TRN-E006, plausible but uncalibrated), and Hamburg candidates reportedly carry the coma signature of light through optics (TRN-E014, unvalidated). For chemistry: the nine sit in the classifier's artifact neighborhood (TRN-E004, with the circularity caveat that its "spurious" class was defined by lacking modern counterparts), the microscopist examining the Caltech plate leaned defect and flagged the plate-corner location (TRN-E024), and the record-backed GRB-era base rate shows star-like defects are routine while confirmed archival transients number zero (TRN-C101). The strongest opposing consideration to this verdict is that the measured evidence currently leans artifact — but with the flash-calibration curve never drawn (TRN-R002) and the coma discriminant never blind-tested (TRN-R003), leaning is all anyone can honestly do.

This is the crux and the file documents, unusually clearly, why it is open in both directions: TRN-E022 removes the copy-chain origin for the canonical nine, but TRN-E024 — from the same manuscript, against interest — states that microscopy cannot separate a sub-second flash from an intrinsic emulsion defect at the single-source level, and the microscopist who examined the plate leaned toward defect. TRN-E004's classifier points to artifact but is trained on a "spurious" class defined by the very property that defines transient candidates, so its force is limited; TRN-E006 is a physics argument without a calibration curve. TRN-E014 is the only record offering a physical incident-light discriminant, and it is unblinded and unvalidated. The strongest opposing consideration is the base-rate one: decades of GRB-era archival searches produced star-like impostors and no confirmed transient, which is a real prior against — but a prior, not a measurement of these marks.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide it.

TRN-E022 removes digitization and copying as origins for the 1950 marks, but the remaining disjunct — original-emulsion defect — is where the inspecting microscopist landed (TRN-E024), and single-source morphology cannot decide between flash and flaw.

Genuinely open. Against: the canonical marks are unusually sharp in exactly the way plate artifacts are (TRN-C002 as read by Hambly & Blair), and a concrete copy-defect pathway exists (TRN-C007). For: sub-second flashes are also expected to be sharp, and Hamburg candidates — outside the Palomar copy lineage — reportedly carry coma signatures of light through the optics (TRN-C011). The decisive observation (original negatives, blinded) has never been made.

Physical inspection confirms that the canonical 1950 marks reside on the original telescope negative, eliminating downstream copying and scanning flaws, and preliminary Hamburg studies report off-axis optical coma consistent with light traversing telescope optics. Conversely, the professional microscopist inspecting the Caltech negative attributed the 1950 marks to localized emulsion defects, and automated morphology classifiers group them with plate artifacts. The strongest opposing consideration is Busko's measurement of optical coma aberration on Hamburg reflector plates, an optical signature that emulsion chemistry cannot easily generate.

This is the case's crux and the evidence is balanced. For: the marks are physical emulsion features on the original 1950 glass (TRN-E022), an independent pipeline recovers them (TRN-E008), the sharp-profile physics argument (TRN-E006), Hamburg analogs outside the Palomar lineage (TRN-E013), and the coma signature (TRN-E014). Against: the random-forest morphology result (TRN-E004), Watters' finding that no feature has been shown to be an optical transient (TRN-E011), and the proponents' own manuscript conceding microscopy cannot classify single sources while quoting its microscopist attributing the features to emulsion defects (TRN-E024). Strongest opposing consideration: TRN-E024 — the closest independent eye on the physical evidence leaned defect, and thecoma discriminant has never been blind-validated.

TRN-E022 removes scanning and downstream copying as explanations for the April marks, and TRN-E014 reports an optical-coma signature in an independent Hamburg archive. Conversely, TRN-E024 states that original- plate microscopy cannot distinguish flashes from intrinsic emulsion defects and records the microscopist's defect-leaning assessment. TRN-E004 and TRN-E011 further support artifact contamination, although neither classifies every individual mark. The strongest positive consideration is therefore the Hamburg coma pattern, while the strongest negative consideration is the unresolved original-emulsion alternative.

Original-negative microscopy places the 1950 nine on the emulsion that was in the telescope, eliminating pure digitization and shared-copy- stage explanations for those events, and Hamburg coma offers a physical light-through-optics signature. Yet the same microscopy manuscript states single-source morphology cannot separate a sub- second flash from an intrinsic emulsion defect, and the microscopist leaned defect. No flash-calibration curve or blind coma validation exists. Strongest opposing consideration: emulsion defects on the original negative remain fully compatible with every morphological fact now in hand.

TRN-E022 removes digitization and copying as explanations for the canonical events, which is real progress, but TRN-E024 — from the same authors, against their own interest — establishes that microscopy cannot separate a sub-second flash from an intrinsic emulsion defect at the single-source level, and its microscopist leaned defect. The one positive physical discriminant, coma aberration (TRN-E014), is an unvalidated single-author preprint on a different archive and does not validate any Palomar event. TRN-E004's classifier points the other way but is circular by construction, since its "spurious" class is defined by absence of a modern counterpart. The claim is genuinely open, and the case's whole ladder rests on it.

The crux. Supporting: TRN-E014 (coma signature, Hamburg only, unvalidated). Undermining: TRN-E004 (artifact-like morphology; classifier circular), TRN-E011 (no feature shown to be an optical transient; 91% of rows near catalog stars). Qualifying: TRN-E006 (flashes should be sharp — uncalibrated), TRN-E024 (microscopy cannot discriminate; microscopist leaned defect). TRN-E021 is context. Presence on the original glass (TRN-E022) narrows the question to flash-versus-emulsion-flaw without answering it.

Supporting: TRN-E014 (moderate; coma pattern on Hamburg candidates, unvalidated, not Palomar). Undermining: TRN-E004 (moderate; classifier groups the nine with artifacts), TRN-E011 (strong; no feature shown to be an optical transient). Qualifying: TRN-E006 (sharpness cuts both ways), TRN-E024 (microscopy cannot separate flash from emulsion flaw; the microscopist leaned defect). TRN-E021 is context. The deciding mechanisms on each side (TRN-C101, TRN-C102) are anchor-only. The verdict is the finding: the crux has narrowed to flash-or-flaw and no admitted record can decide it.

Microscopy of the original 1950 telescope negative confirms the marks exist on the primary emulsion rather than originating in digitization or copying, but microscopy explicitly cannot distinguish sub-second optical flashes from intrinsic emulsion flaws, and an inspecting microscopist favored an emulsion flaw. While preliminary Hamburg plate analyses report telescope-consistent coma aberration, this discriminant has not undergone blind validation. Strongest opposing consideration: Busko's detection of off-axis optical coma patterns matching telescope optics in archival Hamburg Schmidt plates, a signature that emulsion flaws cannot easily replicate.

This is the case's crux and the evidence genuinely straddles it: the marks are physical emulsion features on the original glass (TRN-E022), analogs recur on an independent observatory (TRN-E013), a candidate incident-light discriminant exists in the coma signature (TRN-E014), and sharp profiles are physically consistent with sub-second flashes (TRN-E006). Against this, the microscopy manuscript itself states single-source morphology cannot separate flash from defect (TRN-E024), its microscopist leaned defect, the classifier result (TRN-E004) is interpretation over a circularly defined training class, and the coma discriminant has never been blind-validated. No measurement on either side is currently diagnostic; the strongest opposing consideration is TRN-E024's explicit ceiling.

TRN-E014 supports incident light for some Hamburg candidates through a reported telescope-coma signature, while TRN-E022 removes downstream copying and scanning as explanations for the April 1950 marks. Neither result establishes that the canonical marks were made by light: TRN-E024 says microscopy cannot separate flashes from original-emulsion defects and records a microscopist's defect-leaning judgment. The strongest opposing consideration is that the only optical-path discriminant has not been blind-validated and applies to Hamburg rather than the Palomar events.

Presence on the original emulsion is established for the canonical events (E022), but the same manuscript states that microscopy cannot separate flash from intrinsic defect (E024) and quotes the microscopist leaning defect. Sharpness is ambiguous (E003 vs E004/E006), Hamburg coma is unvalidated (E014), and ordinary defects are known to produce star-like points (E011). Strongest opposing consideration is the explicit non-discriminating ceiling of the only original-plate examination performed to date.

Original-glass microscopy (E022) excludes copying and scanning for the 1950 nine. That leaves flash versus original-emulsion defect, which its own authors say microscopy cannot separate (E024). Sharpness is ambiguous without a flash calibration (E003 vs E006; E004 is circular). The ensemble statistics run on an unvalidated catalog (E011), and coma is unvalidated and Hamburg-only (E014). A prior that some of ~10^5 candidates are mundane real light is reasonable but undemonstrated, and would not advance C021. Strongest opposing consideration: the one outside eye on the original plate attributed the marks to emulsion defects in a defect-prone corner (E024), and the neighbouring plate has comparable marks (E002).

The crux. TRN-E024 establishes that microscopy of single sources cannot separate a flash from an emulsion defect, and its microscopist leaned defect. TRN-E014 reports a coma signature on Hamburg candidates, a potential incident-light test, but it is unvalidated. TRN-E004 and TRN-E011 undermine. TRN-E006 argues that sharpness is expected of flashes but measures nothing. Neither deciding mechanism, TRN-C101 or TRN-C102, has been measured, so no record decides the claim in either direction.