Rømer's determination of the speed of light
type: Thing
description: 1676 experiment which showed that light has finite speed
additional property: PropertyValue
  property ID: P17
  value: France
additional property: PropertyValue
  property ID: P61
  value: Ole Rømer
additional property: PropertyValue
  property ID: P373
  value: Rømer's determination of the speed of light
additional property: PropertyValue
  property ID: P575
  value: August 22, 1676
additional property: PropertyValue
  property ID: P646
  value: /m/09glk55
additional property: PropertyValue
  property ID: P2579
  value: history of physics
additional property: PropertyValue
  property ID: P4431
  value: 340th-anniversary-of-the-determination-of-the-speed-of-light
confidence:
  popularity graph score:
    score: 0.01
    score pct: 1
    tier: long_tail
    components:
      sitelinks: 12
      sitelinks norm: 0.028
      unique citations: 1
      unique citations norm: 0.0
      monthly pageviews: 322
      monthly pageviews norm: 0.0
  sitelinks: 12
  unique citations: 1
  monthly pageviews: 322
  yearly pageviews: 1032
  pageview trend:
    m: 2026-08
    v: 322
  pageview trend:
    m: 2026-07
    v: 232
  pageview trend:
    m: 2026-06
    v: 137
  pageview trend:
    m: 2026-05
    v: 5
  pageview trend:
    m: 2026-05
    v: 97
  pageview trend:
    m: 2026-05
    v: 13
  pageview trend:
    m: 2026-05
    v: 5
  pageview trend:
    m: 2026-05
    v: 7
  pageview trend:
    m: 2026-04
    v: 1
  pageview trend:
    m: 2026-04
    v: 193
  pageview trend:
    m: 2026-04
    v: 5
  pageview trend:
    m: 2026-04
    v: 3
  pageview trend:
    m: 2026-04
    v: 12
  popularity:
    sitelinks: 12
    max: 423
    pct: 2.8
  tier: long_tail
claims:
  P17:
    value: Q142
    source count: 0
    confidence: 0.0
    value label: France
  P31:
    value: Q134348943
    source count: 0
    confidence: 0.0
  P61:
    value: Q160187
    source count: 0
    confidence: 0.0
    value label: Ole Rømer
  P373:
    value: Rømer's determination of the speed of light
    source count: 0
    confidence: 0.0
  P575:
    value: +1676-08-22T00:00:00Z
    source count: 0
    confidence: 0.0
  P646:
    value: /m/09glk55
    source count: 1
    confidence: 0.2
  P2579:
    value: Q212881
    source count: 0
    confidence: 0.0
    value label: history of physics
  P4431:
    value: 340th-anniversary-of-the-determination-of-the-speed-of-light
    source count: 0
    confidence: 0.0
citations:
  source: Freebase Data Dumps
  stated in qid: Q15241312
  pub year: 2013
meta:
  wikidata id: Q2898393
  level: standard
  html url: https://4ort.xyz/entity/r-mer-s-determination-of-the-speed-of-light
  markdown url: https://4ort.xyz/entity/r-mer-s-determination-of-the-speed-of-light.md
  facts url summary: https://4ort.xyz/entity/r-mer-s-determination-of-the-speed-of-light/facts.json
  facts url standard: https://4ort.xyz/entity/r-mer-s-determination-of-the-speed-of-light/facts.json
  facts url full: https://4ort.xyz/entity/r-mer-s-determination-of-the-speed-of-light/facts.json
  data source: Wikidata (CC0 / public domain)
  license: https://creativecommons.org/publicdomain/zero/1.0/
  api version: v1
  served at: 2026-08-06T22:03:30.209869Z
  entity updated at: 2026-05-03T21:19:00.258443+00:00Z
  entity created at: 2026-04-11T00:04:51.131602+00:00Z