Nicole HaygesShyla Henry

Period 4

The Greek

Astronomers

Due to their contribution in

mathematics and astronomy, Ancient Greek Astronomers

are known world wide.

Aristarchus of Samos310-230 B.C.

Aristarchus is known for his suggestion of the sun being in the center of the universe instead of earth being the center of the universe. He also is known for his estimation of the distance from the sun to the earth by observing the angle between the moon when it is exactly half full.

Anaxagoras500 B.C.

His most important idea was that people should not trust use their senses (seeing and hearing) or their common sense to tell them about the world, but they should always use logic and reason to figure out truth instead.

ThalesMiletus, about 630 B.C. Thales was the first

Greek scientist that

we know of who did

not try to explain the

weather and the

stars and planets as

things controlled by

the gods. Thales was

right that everything

is made out of the

same things, but

those things are

electrons and protons, not water.

He understood that

the earth was round,

and that the moon

was lit by light reflecting from the

sun.

CononSamos, 283-222 B.C.

Conon was a Greek mathematician and astronomer. Headed the Alexandrian library after Euclid. Conon discovered a new stellar formation that he named Come (or Plocamos) Berenices, in honor of Berenice, queen of Ptolemaios III Evergetes.

Eratosthenes of Cyrene276-200 B.C.

Greek astronomer and mathematician. Calculated the circumference of the Earth and finds a figure of 46,000 km which is close to the present measured value. Also lays down the first lines of longitude on a map of Earth. He also developed a method for calculating all prime numbers: the sieve of Eratosthenes.

Sosigenes1st Century B.C

He was a Greek astronomer and

mathematician. His advice to Julius Caeser led to the

adoption of the Julius calendar, which stayed in effect until 1578 when it

was changed by Pope Gregory XIII.

Hipparchus of Nicea190-120 B.C

He was a Greek astronomer and mathematician. He’s Considered the greatest astronomer of ancient times. Developed a system of planetary motion with the Earth at the center. This system was later refined by Ptolemy. Used data from a total eclipse of the sun and parallax to determine correctly the distance and size of the moon. The same data gave values for the distance and size of the sun an order of magnitude smaller than there actual values. Compiled the first tables of cord length, forerunner of trigonometric tables.

Seleucus190-? B.C.

Last known astronomer to champion the heliocentric

theory of the solar system

until Copernicus.

Poseidonius140-50 B.C

He calculated the Earth’s circumference, which 1500 year later,

led Columbus to believe that Asia was only

about 3000 miles west of Europe.

Greek astronomer and mathematician. His advice to Julius Caesar led to the

adoption of the Julius calendar, which stayed in effect until 1578 when it

was changed by Pope Gregory.

Sosigenes1st century b.c

Ptolemy ClaudiusThe last great Alexandrian

astronomer. Refined the system of

planetary motion developed by

Hipparchus, which had Earth at the center of

the universe, known as the “Ptolemaic

System”. Best known for his Almagest

HipatiasThe last ancient

philosopher and

astronomer. The only

woman astronome

r in ancient Greek

history.

The End!

http://www.greek-names.info/names-of-ancient-greek-astronomers/