Views & Theories of the Universe
Ptolemy’s Theory Proposed around 127-145 AD Earth was the center of the universe The sun, moon, stars, and planets all orbited in a circle around the earth
Ptolemy’s Theory
Copernicus’ Theory Proposed in 1543 The Sun was the center of the universe The earth and planets all orbited in a circle around the sun; The moon orbited around the earth The stars did not move
Copernicus’ Theory
Kepler’s Theory Proposed in 1609 Planets move around the sun in an elliptical motion, not a circular motion Planets speed up as they approach the sun and slow down as they move away
Kepler’s Theory
Big Bang Theory Proposed in 1927 Universe was smaller than a pinhead, then it exploded and expanded As the universe cooled, hydrogen and helium atoms began to form The universe is slowly expanding to this day
Big Bang Theory
Steady State Theory Developed in 1948 The universe has no beginning and no end The universe is in perfect balance (when stars die, new ones are created – like when a faucet is running and fills up a sink and the sink stays full)
Steady State Theory
Inflation Theory Proposed around 1980 The universe rapidly (and exponentially) expanded in its first few moments. Extension of the Big Bang theory
Inflation Theory