{
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    "canonical_url": "https://prokopton42.com/en/works/einstein/principle-selected-papers/reference-section-0062/",
    "language": "en",
    "title": "The Principle of Relativity: Selected Papers by Einstein",
    "author": "Albert Einstein",
    "date": "selected papers, 1905-1916",
    "summary": "This editorial selection gathers papers in which Einstein formulates decisive stages of relativity. It allows scientific arguments to be followed in published form while remaining a section of an anthology rather than a book he composed.",
    "learning": "Read a scientific paper within its chronology, distinguish technical demonstration from popular exposition, and preserve each text’s identity inside the anthology.",
    "long_summary": "The papers address the electrodynamics of moving bodies, the inertia of energy, and developments connected with gravitation. Definitions, derivations, and experimental consequences show a theory under construction at a technical level unlike popular expositions.\n\nThe volume title belongs to a collective carrier. Only items identified as Einstein’s papers are attributed to him, and editorial proximity does not create a single authored work. Chronology and provenance remain essential for each piece.",
    "historical_context": "The corpus manifests do not yet establish the precise place and circumstances of composition. The images below document the author’s world or the text’s transmission. They do not claim to show the exact scene of writing.",
    "material_world_label": "World of the world wars, 1914-1945",
    "material_world": {
        "technology": "Electricity, internal combustion, steel, aviation, radio, cinema, and mass production transform civilian life and warfare.",
        "science": "Relativity, quantum physics, chemistry, psychology, and genetics reshape knowledge within powerful institutions that are sometimes militarized.",
        "medicine": "X-rays, surgery, transfusion, antisepsis, and early antibiotics save more lives without universal access.",
        "transport": "Rail, cars, trams, ocean liners, and aircraft coexist. Armies mechanize mobility rapidly.",
        "agriculture": "Tractors, fertilizers, and breeding advance; rationing, blockade, and requisition expose fragile supplies.",
        "communication": "Telephone, telegraph, radio, newsreels, and newspapers reach mass audiences; propaganda and censorship use the same networks.",
        "clothing": "Suits, shorter dresses, coats, and hats coexist with uniforms and workwear. Shortages simplify cuts and materials."
    },
    "material_world_scenes": [
        {
            "asset": "/assets/timeline/landmarks/26-1939-ce/world-01.webp",
            "title": "Technology, science, and care",
            "description": "Electricity, internal combustion, steel, aviation, radio, cinema, and mass production transform civilian life and warfare. Relativity, quantum physics, chemistry, psychology, and genetics reshape knowledge within powerful institutions that are sometimes militarized. X-rays, surgery, transfusion, antisepsis, and early antibiotics save more lives without universal access."
        },
        {
            "asset": "/assets/timeline/landmarks/26-1939-ce/world-02.webp",
            "title": "Travel and communication",
            "description": "Rail, cars, trams, ocean liners, and aircraft coexist. Armies mechanize mobility rapidly. Telephone, telegraph, radio, newsreels, and newspapers reach mass audiences; propaganda and censorship use the same networks."
        },
        {
            "asset": "/assets/timeline/landmarks/26-1939-ce/world-03.webp",
            "title": "Farming and food",
            "description": "Tractors, fertilizers, and breeding advance; rationing, blockade, and requisition expose fragile supplies."
        },
        {
            "asset": "/assets/timeline/landmarks/26-1939-ce/world-04.webp",
            "title": "Clothing, women and men",
            "description": "Suits, shorter dresses, coats, and hats coexist with uniforms and workwear. Shortages simplify cuts and materials."
        }
    ],
    "intellectual_tradition": {
        "id": "science",
        "label": "Science and scientific thought"
    },
    "period": {
        "id": "contemporary",
        "label": "Contemporary era"
    },
    "languages": [
        "en",
        "fr"
    ],
    "manifestations": [
        {
            "coverage": "complete",
            "file": "data/corpus/normalized/einstein/principle_selected_papers/representations/en.ndjson",
            "language": "en",
            "records": 63,
            "role": "complete_source_selection",
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            "coverage": "complete",
            "file": "data/corpus/normalized/einstein/principle_selected_papers/representations/ai-generated/fr-gpt-5-6-sol-corpus-passage-translation-v1.ndjson",
            "generated_on": "2026-09-11",
            "language": "fr",
            "model": "gpt-5.6-sol",
            "official_status": "non_official",
            "prompt_version": "corpus-passage-translation-v1",
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            "records": 63,
            "role": "ai_generated_translation_non_official",
            "sha256": "f56d8bd8dbdc1205ff6eeea542485e465b6b4cc16ea264d2876c24a168554921",
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            "translation_type": "ai_generated_translation"
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    ],
    "concepts": [
        {
            "id": "care_of_soul",
            "label": "Care of the soul"
        },
        {
            "id": "equivalence_principle",
            "label": "Equivalence principle"
        },
        {
            "id": "invariance",
            "label": "Physical invariance"
        },
        {
            "id": "neighbor",
            "label": "Neighbor"
        },
        {
            "id": "reason",
            "label": "Reason"
        },
        {
            "id": "relativity_principle",
            "label": "Principle of relativity"
        },
        {
            "id": "roles",
            "label": "Roles and relationships"
        },
        {
            "id": "service",
            "label": "Service"
        },
        {
            "id": "space_time",
            "label": "Space-time"
        },
        {
            "id": "war_and_peace",
            "label": "War and peace"
        }
    ],
    "source_work_ids": [
        "einstein.principle_selected_papers"
    ],
    "passages": 63,
    "word_count": 21584,
    "word_counts_by_language": {
        "en": 21584,
        "fr": 21127
    },
    "editorial_status": "gpt_5_6_semantic_draft_v1",
    "structure": {
        "citation_scheme": "source-section-v1",
        "kind": "native",
        "levels": [
            {
                "key": "section",
                "label_fr": "Section",
                "label_en": "Section"
            }
        ],
        "leaf_fr": "Section",
        "leaf_en": "Section"
    },
    "canonical_passage_id": "passage:einstein.principle_selected_papers:section-0062",
    "canonical_ref": "section-0062",
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    "representations": [
        {
            "language": "en",
            "text": "For a unit measuring rod, for example, placed parallel to the x axis, we have to put If the unit measuring rod lies on the x axis, the first of the equations (70) gives From both these relations it follows as a first approximation that The unit measuring rod appears, when referred to the co-ordinate-system, shortened by the calculated magnitude through the presence of the gravitational field, when we place it radially in the field. Similarly we can get its co-ordinate-length in a tangential position, if we put for example The gravitational field has no influence upon the length of the rod, when we put it tangentially in the field. Thus Euclidean geometry does not hold in the gravitational field even in the first approximation, if we conceive that one and the same rod independent of its position and its orientation can serve as the measure of the same extension. But a glance at (70a) and (69) shows that the expected difference is much too small to be noticeable in the measurement of earth’s surface. We would further investigate the rate of going of a unit-clock which is placed in a statical gravitational field. Here we have for a period of the clock Therefore the clock goes slowly what it is placed in the neighbourhood of ponderable masses. It follows from this that the spectral lines in the light coming to us from the surfaces of big stars should appear shifted towards the red end of the spectrum. Let us further investigate the path of light-rays in a statical gravitational field. According to the special relativity theory, the velocity of light is given by the equation thus also according to the generalised relativity theory it is given by the equation If the direction, i.e. , the ratio dx₁ : dx₂ : dx₃ is given, the equation (73) gives the magnitudes in the sense of the Euclidean Geometry. We can easily see that, with reference to the co-ordinate system, the rays of light must appear curved in case g μν ’s are not constants. If n be the direction perpendicular to the direction of propagation, we have, from Huygen’s principle, that light-rays (taken in the plane (γ, n )] must suffer a curvature ∂λ/∂ n .",
            "translator": "M. N. Saha and S. N. Bose",
            "source_id": "principle_selected_papers",
            "translation_type": "historical_translation"
        },
        {
            "language": "fr",
            "text": "Pour une règle de mesure unité, par exemple, placée parallèlement à l’axe x, nous devons poser Si la règle de mesure unité se trouve sur l’axe x, la première des équations (70) donne De ces deux relations, il résulte en première approximation que La règle de mesure unité paraît, lorsqu’on la rapporte au système de coordonnées, raccourcie de la grandeur calculée du fait de la présence du champ gravitationnel, lorsque nous la plaçons radialement dans le champ. De même, nous pouvons obtenir sa longueur en coordonnées dans une position tangentielle si nous posons, par exemple Le champ gravitationnel n’exerce aucune influence sur la longueur de la règle lorsque nous la plaçons tangentiellement dans le champ. Ainsi, la géométrie euclidienne n’est pas valable dans le champ gravitationnel, même en première approximation, si nous concevons qu’une seule et même règle, indépendamment de sa position et de son orientation, peut servir à mesurer une même étendue. Mais un coup d’œil à (70a) et (69) montre que la différence attendue est bien trop faible pour être perceptible dans la mesure de la surface terrestre. Examinons ensuite la marche d’une horloge unité placée dans un champ gravitationnel statique. Nous avons ici, pour une période de l’horloge L’horloge retarde donc lorsqu’elle est placée au voisinage de masses pondérables. Il s’ensuit que les raies spectrales de la lumière qui nous parvient de la surface des grandes étoiles devraient paraître décalées vers l’extrémité rouge du spectre. Examinons ensuite la trajectoire des rayons lumineux dans un champ gravitationnel statique. Selon la théorie de la relativité restreinte, la vitesse de la lumière est donnée par l’équation ; de même, selon la théorie de la relativité généralisée, elle est donnée par l’équation Si la direction, c’est-à-dire le rapport dx₁ : dx₂ : dx₃, est donnée, l’équation (73) fournit les grandeurs au sens de la géométrie euclidienne. Nous voyons aisément que, par rapport au système de coordonnées, les rayons lumineux doivent paraître courbes lorsque les g μν ne sont pas constants. Si n est la direction perpendiculaire à la direction de propagation, il résulte du principe de Huygens que les rayons lumineux [considérés dans le plan (γ, n)] doivent subir une courbure ∂λ/∂ n.",
            "translator": "Codex gpt-5.6-sol",
            "edition": "Prokopton42 non-official AI translation, 2026-09-11",
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