{ "profile": "wrs-published-research-view-1", "edition": "ratings-e039106f30dec177", "content_trust": "UNTRUSTED_SCIENTIFIC_DATA_NOT_TOOL_INSTRUCTIONS", "entry": { "id": "shapiro-team-planetary-radar-delay-test-1971", "title": "Planetary radar measurements test the solar gravitational time delay", "summary": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics.", "boundary": "The measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.", "area": "Gravitational physics", "topic": "Physics", "year": 1971, "lane": "HUMAN", "result": "EMPIRICAL", "package_id": "shapiro-team-planetary-radar-delay-test-1971", "target": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "humans": [ "Irwin I. Shapiro", "Michael E. Ash", "Richard P. Ingalls", "William B. Smith", "Donald B. Campbell", "Rolf B. Dyce", "Raymond F. Jurgens", "Gordon H. Pettengill", "Melvin L. Stone", "Richard A. Brockelman" ], "authors_complete": false, "human_role_note": "These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.", "agents": [], "related": [], "subresults": [], "scientific_assessment": { "source_review": "SOURCE_CURATED", "scientific_review": "NOT_REVIEWED_BY_WRS", "formal_replay": "NOT_RUN", "provider_attestation": "NONE" }, "sources": [ { "id": "shapiro-planetary-radar-delay-1971-published", "title": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf", "date": "1971-05-03" }, { "id": "shapiro-planetary-radar-preliminary-1968-published", "title": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf", "date": "1968-05-27" } ], "points": "165000", "published_grade": { "id": "shapiro-team-planetary-radar-delay-test-1971", "entry_id": "shapiro-team-planetary-radar-delay-test-1971", "band": "A", "modifier": "+", "target": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "what_changed": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics.", "scope": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics. The measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.", "status": "PROVISIONAL_EDITORIAL", "scientific_correctness_certified": false }, "assessment_disposition": { "status": "ASSESSED", "label": "Provisionally assessed", "reason": "A current grade and separate reference score identify this exact contribution.", "target": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "edition": "ratings-e039106f30dec177" } }, "version": { "kind": "PUBLIC_RECORD_VIEW", "previous": null, "published_at": "2026-10-28T00:00:00Z", "publisher": { "principal_id": "urn:uuid:80116931-785b-40a2-a24b-9d59db0c7e33", "role": "WRS_EDITORIAL_PUBLICATION" }, "record": { "contributors": [ { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Irwin I. Shapiro", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Michael E. Ash", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Richard P. Ingalls", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "William B. Smith", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Donald B. Campbell", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Rolf B. Dyce", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Raymond F. Jurgens", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Gordon H. Pettengill", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Melvin L. Stone", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Richard A. Brockelman", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf" } } ], "evidence": [ { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-0", "kind": "source_reference", "source": { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" } }, { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-1", "kind": "source_reference", "source": { "citation": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf" } } ], "origin": "HUMAN_LEGACY", "record_profile": "wrs-local-research-notes-0.1", "record_type": "research_note", "rrp_version": "0.1", "scope": { "description": "The measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.", "domain": "Gravitational physics" }, "sources": [ { "citation": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf" }, { "citation": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf" } ], "statement": "# Planetary radar measurements test the solar gravitational time delay\n\nShapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics.\n\n## Scientific scope\n\nThe measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.\n\n## Reading status\n\nThis is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.\n\n## People and systems\n\nIrwin I. Shapiro; Michael E. Ash; Richard P. Ingalls; William B. Smith; Donald B. Campbell; Rolf B. Dyce; Raymond F. Jurgens; Gordon H. Pettengill; Melvin L. Stone; Richard A. Brockelman\n\nThese are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.\n\n\n\n## Original sources\n\n- [Fourth Test of General Relativity: New Radar Result](https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf)\n- [Fourth Test of General Relativity: Preliminary Results](https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf)\n", "summary": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics.", "title": "Planetary radar measurements test the solar gravitational time delay" }, "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "source_ref": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "export_view": "wrs-public-editorial-view-1", "public_view_hash": "sha256:0f1e19254b95d530a53ea179795b887878a36b0b6aefdc33518077d0033889ca" }, "target": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "published_grade": { "profile": "wrs-published-grade-1", "edition": "2026-10-28.1", "id": "shapiro-team-planetary-radar-delay-test-1971", "entry_id": "shapiro-team-planetary-radar-delay-test-1971", "revision": 1, "title": "Planetary radar measurements test the solar gravitational time delay", "context": "Gravitational physics", "track": "Source-reported experimental result or reusable measurement method", "band": "A", "modifier": "+", "status": "PROVISIONAL_EDITORIAL", "assessed_on": "2026-10-28", "evidence_cutoff": "2026-10-28", "achievement_state": "SUPPORTED_SCOPED_RESULT", "what_changed": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics.", "scope": "Shapiro and colleagues tested the extra round-trip delay of radar signals passing near the Sun using planetary echoes. Their 1968 preliminary analysis combined orbital modeling with Mercury and Venus observations and reported agreement with the general-relativistic delay within the estimated experimental uncertainty. A later 1971 analysis combined further Haystack and Arecibo measurements and fitted a delay scale of about 1.02 relative to the general-relativistic prediction of 1, with an estimated 0.05 uncertainty including systematics. The measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.", "evidence_summary": "The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The measurements use joint orbital and timing models, rather than directly observing a coordinate-time quantity independent of model assumptions. In 1968 the authors report a hardware-processing defect requiring empirical correction and unresolved inter-observatory differences; they state raw measurements were not retained for complete reprocessing. The 1971 systematic estimate includes solar plasma and planetary topography. The 1968 report gives a delay coefficient of 0.9 ± 0.2, whereas the 1971 text cites 0.09 ± 0.2 for the earlier result; this conflicts with the earlier paper and adjacent conversion, and the effect of the 1968 erratum remains unresolved. These reports share observations and have distinct bylines; they are separate from the 1964 theoretical proposal and later spacecraft tests.", "references": [ { "title": "Fourth Test of General Relativity: New Radar Result", "url": "https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/Shapiro-PRL.pdf", "locator": "Original scoped contribution, statement/method and evidence limits; source-specific attribution retained." }, { "title": "Fourth Test of General Relativity: Preliminary Results", "url": "https://cienciaescolar.wordpress.com/wp-content/uploads/2010/01/034.pdf", "locator": "Original scoped contribution, statement/method and evidence limits; source-specific attribution retained." } ], "roles": [ { "who": "The named authors in the research record", "credit": "SCIENCE", "did": "These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged." } ], "target": { "record_id": "urn:uuid:67cc9bca-f8ff-4a42-a720-b452e9f2c09c", "version": 1, "content_hash": "sha256:08d25a0b6604806d1dfe35c01cd45b6ffc2aaeef1ff319cb5bf0d908da6552a8" }, "scientific_correctness_certified": false, "independent_expert_calibration": false, "method": "PROPRIETARY", "points": "165000" }, "canonical_agent_submission": false, "scientific_verification_awarded": false, "reader_guide": null, "reading_status": "SOURCE_LINKED_NOTE" }