# refractive index

> ratio of the speed of light in vacuum to that in the medium

**Wikidata**: [Q174102](https://www.wikidata.org/wiki/Q174102)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Refractive_index)  
**Source**: https://4ort.xyz/entity/refractive-index


## References

1. Integrated Authority File
2. ISO 80000-1:2009 Quantities and units—Part 1: General
3. Nuovo soggettario
4. Freebase Data Dumps. 2013
5. ISO 80000-7:2008 Quantities and units—Part 7: Light
6. ISO 80000-7:2019 Quantities and units — Part 7: Light and radiation
7. Quora
8. ISO 80000-3:2019 Quantities and units — Part 3: Space and time
9. SI Brochure (9th edition): Concise summary
10. National Library of Israel
11. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)