ASTRONONMERS TIMELINE

ARISTOTLE

• 384 BCE-322 BCE
• He believed in a geocentric universe
• He thought that the stars and plantes were perfect spheres
• He proved that the earth was spherical

ARISTARCHUS

• Lived from 310 BC- 230 BC
• He was the first to present the first model that placed then sun in the center of the universe

PTOLEMY

• He lived from 367 BC- 283 BC
• He believed that earth was at the center of thr universe with the moon, venus, sun, mars and jupiter.. ETC surrounding

NICOLAUS COPERNICUS

• He lived from 1473-1543
• Described an astronomical system in which a central fire(similar to the sun) occupied thr center of thr universe

JOHANESE KEPLER

• He lived from 1571-1630
• Keplers laws

Kepler's 1'st law

• planets orbit the earth in an un-perfect path
• the sun is at one focus point of the pathway

Kepler's 2'nd law

• planets follow the orbit in with equal areas and timing got all planets

kepler's 3'rd law

• There is a mathematical reason for all of this and the time
• the time and distance between the planet also has a mathematical reasoning 

GALILEO GALILEI

• He lived from 1564-1642
• Helped make improvements to the newley invented telescope
• He proved that earth isn't the only thing to orbit

ISAAC NEWTON

• He lived from 1643-1727
• He formulated the laws of motion and universal gravitation
• Its also demonstrated the motion of objects

EDWIN HUBBLE

• He lived from 1889-1953
• He had a crucial role in establishing the feild of extragalactic astronomy
• His greatest discovery was in 1929 when he identified the relationship between a galaxy's distance and the speed at which its moving

CARL SAGAN

• He lived from 1934-1996
• He discovered the high surface temperatures on Venus
• He published more than 600 scientific papers

STEPHEN HAWKING

• He was born 1942- present day
• He studies black holes and their physical charactistics
• He wrote a book all about the black holes