# Hippocrates of Chios

> 5th-century BC Greek mathematician and astronomer

**Wikidata**: [Q312629](https://www.wikidata.org/wiki/Q312629)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Hippocrates_of_Chios)  
**Source**: https://4ort.xyz/entity/hippocrates-of-chios

## Summary
Hippocrates of Chios was a 5th-century BC Greek mathematician and astronomer recognized as a geometer. He is most notable for his work on the quadrature of the lunes, a geometric shape bounded by arcs of two circles.

## Biography
*   **Born:** Circa 470 BC (sources indicate -0470-01-01T00:00:00Z, -0470-00-00T00:00:00Z, and -0500-00-00T00:00:00Z) in Chios.
*   **Died:** Circa 410 BC (-0410-01-01T00:00:00Z).
*   **Nationality:** Greek.
*   **Occupations:** Mathematician, astronomer, geometer, shopkeeper.
*   **Fields:** Astronomy, Geometry.
*   **Notable Works:** Lune of Hippocrates.

## Contributions
Hippocrates of Chios made significant contributions to the field of geometry, specifically through his study of the "lune of Hippocrates." This geometric shape is defined as an area bounded by arcs of two circles, distinguished by the property that its area is a rational multiple of the circles' radii. His work in this area was a notable attempt to solve the problem of squaring the circle. Additionally, he was active in the field of astronomy, engaging in the study of celestial objects and phenomena.

## FAQs
**What was Hippocrates of Chios's primary profession?**
He was a mathematician and astronomer who worked as a geometer, though he was also recorded as having been a shopkeeper.

**What is the "lune of Hippocrates"?**
The lune of Hippocrates is a geometric shape bounded by arcs of two circles, notable because its area is a rational multiple of the circles' radii.

**What time period did Hippocrates of Chios live in?**
He lived during the 5th century BC, with birth dates estimated around 470 BC or 500 BC and death estimated around 410 BC.

## Why They Matter
Hippocrates of Chios matters for his pioneering work in geometry, particularly his investigation into the quadrature of lunes. By demonstrating that the area of a specific lune could be expressed in terms of the radii of the circles involved, he made early strides in the attempt to square the circle, a problem that fascinated ancient mathematicians. His dual role as a mathematician and astronomer places him among the foundational figures in the Greek exact sciences, contributing to the systematic organization of knowledge in geometry and the study of celestial bodies.

## Notable For
*   Being a 5th-century BC Greek mathematician and astronomer.
*   Authoring the notable work "Lune of Hippocrates."
*   Working as a geometer studying geometry.
*   Being identified as a shopkeeper before his mathematical career.
*   Contributing to the fields of astronomy and geometry.

## Body

### Early Life and Background
Hippocrates of Chios was born around the year 470 BC (with some records suggesting dates around 500 BC) on the island of Chios. He is identified as a human member of the species Homo sapiens. While he is primarily known for his intellectual pursuits, historical records indicate that his occupation included being a shopkeeper, suggesting a transition from commerce to scholarship.

### Mathematical Contributions
As a geometer, Hippocrates focused extensively on geometry. His most famous contribution is the "lune of Hippocrates." A lune is a shape bounded by arcs of two circles. Hippocrates demonstrated that the area of this specific lune is a rational multiple of the circles' radii. This discovery was significant in the history of mathematics as it related to the broader problem of squaring the circle. His work is formally recognized under the notable work identifier Q782019.

### Work in Astronomy
In addition to his geometric work, Hippocrates was an astronomer. This field is defined as the natural science dedicated to the study of celestial objects and phenomena originating outside the Earth's atmosphere. Astronomy is classified as an exact science and a branch of physical science. During the time of Hippocrates, the field involved systematic observation and theoretical modeling to organize knowledge about the cosmos. While specific observations by Hippocrates are not detailed in the provided data, his classification as an astronomer aligns him with the study of stars, galaxies, and celestial mechanics.

### Historical Context and Identifiers
Hippocrates of Chios is documented in various academic and knowledge systems. He is listed with VIAF ID 42631297 and has multiple identifiers across library and academic databases, including:
*   **GND ID:** 118639633
*   **SUDOC:** 243159846
*   **Mathematics Genealogy Project ID:** 1354
*   **MacTutor Biography ID:** Hippocrates_of_Chios
*   **Treccani ID:** ippocrate-di-chio
*   **Store norske leksikon ID:** Hippokrates_fra_Khios

His aliases include simply "Hippocrates," and his name in Ancient Greek is recorded as Ἱπποκράτης. He has a sitelink count of 43 and his biography is preserved in numerous encyclopedic entries, such as Britannica (biography/Hippocrates-of-Chios) and Wikipedia.

## References

1. Eudemian Ethics
2. Virtual International Authority File
3. [Hippokrates fra Khios. 2025](https://snl.no/Hippokrates_fra_Khios)
4. [Ippocrate di chio - Enciclopedia](https://www.treccani.it/enciclopedia/ippocrate-di-chio_(Enciclopedia-della-Matematica)/)
5. Freebase Data Dumps. 2013
6. CERL Thesaurus
7. Treccani's Enciclopedia on line
8. Enciclopedia Treccani
9. HMML Authority File