@prefix rdf: . @prefix xsd: . @prefix dcterms: . @prefix skos: . @prefix rdfs: . @prefix api: . @prefix foaf: . skos:narrower . skos:broader . a rdfs:Resource , skos:Concept ; dcterms:contributor ; dcterms:modified "2020-11-03T20:18:43.377Z"^^xsd:dateTime ; skos:altLabel "Doppler effect"@en ; skos:broader ; skos:definition "Effect of the relative motion of a wave source (light, sound) and the observer. If the source is moving away, the wavelength is stretched (shifted toward lower frequencies). If the source is approaching, the wavelength is compressed (shifted toward higher frequencies). These effects, known as Doppler shifts, are in the case of light waves called redshift and blueshift, respectively."@en ; skos:narrower , ; skos:prefLabel "Doppler shift"@en . skos:broader . a api:ItemEndpoint , api:Page ; api:definition ; api:extendedMetadataVersion ; foaf:primaryTopic .