**Hipparchus of Nicaea** (/hɪˈpɑːrkəs/; Greek: Ἵππαρχος, Hipparkhos; c. 190 – c. 120 BC) was a Greek astronomer, geographer, and mathematician.

Contents

- 1 When was Hipparchus born?
- 2 What did Hipparchus do as a kid?
- 3 When and where was Hipparchus born?
- 4 Where was Hipparchus born?
- 5 How did Hipparchus discover trigonometry?
- 6 What did Eratosthenes do?
- 7 What did Ptolemy do?
- 8 What did aristarchus do?
- 9 What did Aristarchus discover?
- 10 When was Hipparchus died?
- 11 Who invented epicycles?

## When was Hipparchus born?

Hipparchus, also spelled Hipparchos, (born, Nicaea, Bithynia [now Iznik, Turkey]—died after 127 bce, Rhodes?), Greek astronomer and mathematician who made fundamental contributions to the advancement of astronomy as a mathematical science and to the foundations of trigonometry.

## What did Hipparchus do as a kid?

Born in Nicaea, Bithynia (now Iznik, Turkey), Hipparchus lived in the 2nd century bc. As a young man he compiled records of local weather patterns throughout the year.

## When and where was Hipparchus born?

Ṭūsī was the first ( c. 1250 ) to write a work on trigonometry independently of astronomy. But the first modern book devoted entirely to trigonometry appeared in the Bavarian city of Nürnberg in 1533 under the title On Triangles of Every Kind. Its author was the astronomer Regiomontanus (1436–76).

## Where was Hipparchus born?

A Greek mathematician and astronomer, he measured the earth-moon distance accurately, founded the mathematical discipline of trigonometry, and his combinatorics work was unequalled until 1870. Hipparchus discovered the precession of the equinoxes and observed the appearance of a new star – a nova.

## How did Hipparchus discover trigonometry?

Hipparchus produced a table of chords, an early example of a trigonometric table. He did this by using the supplementary angle theorem, half angle formulas, and linear interpolation. Hipparchus calculated the length of the year to within 6.5 minutes and discovered the precession of the equinoxes.

## What did Eratosthenes do?

Eratosthenes, in full Eratosthenes of Cyrene, (born c. 276 bce, Cyrene, Libya—died c. 194 bce, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth for which any details are known.

## What did Ptolemy do?

Ptolemy made contributions to astronomy, mathematics, geography, musical theory, and optics. He compiled a star catalog and the earliest surviving table of a trigonometric function and established mathematically that an object and its mirror image must make equal angles to a mirror.

## What did aristarchus do?

Aristarchus of Samos, (born c. 310 bce—died c. 230 bce), Greek astronomer who maintained that Earth rotates on its axis and revolves around the Sun.

## What did Aristarchus discover?

Aristarchus estimated the sizes of the Sun and Moon as compared to Earth’s size. He also estimated the distances from the Earth to the Sun and Moon. He is considered one of the greatest astronomers of antiquity along with Hipparchus, and one of the greatest thinkers in human history.

## When was Hipparchus died?

Hipparchus of Nicaea (/hɪˈpɑːrkəs/; Greek: Ἵππαρχος, Hipparkhos; c. 190 – c. 120 BC) was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of precession of the equinoxes.

## Who invented epicycles?

It was developed by Apollonius of Perga and Hipparchus of Rhodes, who used it extensively, during the 2nd century BC, then formalized and extensively used by Ptolemy of Thebaid in his 2nd century AD astronomical treatise the Almagest.