ASTRONOMY

ARISTOTLE

• proved that the Earth is spherical
• he thought that Earth was the center of the universe
• if the earth rotated around the sun he should see stars shift places

ARISTARCHUS

• measured the distance between the Earth and the Sun
• measured the distance between the Earth and the moon
• Thought that the sun was the center of the universe
• came to this conclusion 1,750 years before Copernicus did
• People thought his theory was to radical

PTOLEMY

• model of the solar system where everything revolved around Earth.
• It was used for hundreds of years but it was wrong
• visualized an Earth-centered universe
• Thought that astronomical objects move at constant speeds in circular orbits
• Ptolemaic model is one of the longest upheld scientific theories in history

COPERNICUS

• made a model of the solar system with Earth moving around the sun
• in his revisions of that model he kept the orbits circular
• revolutionary idea was not popular with the Church
• Concluded that Earth rotates around the sun
• Thought that the Ptolemaic system was contrived

KEPLER

• planets traveled around the sun not in circles but in ellipses
• used the idea of elliptical orbits to describe the motions of the planets
• line from the Sun to a planet sweeps out equal areas in equal amounts of time
• years▫️of a planet's orbital period=the cube of that planet's distance to Sun

GALILEO GALILIE

• improved existing telescope models
• discovered the four primary moons of Jupiter
• discovered the rings of Saturn.
• saw the craters, mountains, and valleys of the Moon

NEWTON

• three laws describing the motion of forces between objects known as newton's laws
• Objects at rests stays at rest or objects in motion says in motion
• The relationship between object's mass m, acceleration a, applied force F is F = ma
• For every action there is an equal and opposite reaction.

HUBBLE

• calculated that a small blob in the sky existed outside of the Milky Way
• galaxies recede from each other at a rate equal to their distance from another
• determined that the universe itself was expanding