-
100
Big Bang (13.7 billion years ago)
A huge explosion that came from nothing. All matter and energy are in a single point, and the laws of physics are not understood at that time. -
101
Stonehenge (3100-2800 BC)
It kept track of solar and lunar eclipses. Had true astronomical alignment. -
120
Hipparchus (190-120 BC)
Said the earth has 3 motions, it wobbles, orbits, and rotates. -
170
Ptolemy (100-170 AD)
Started the theory of a geocentric model. He is known as the wrongest for the longest. -
230
Aristarchus (310-230 BC)
Thought the sun was the center of the solar system, he was totaly ignored. He looked at the distance and size of the sun compared to the moon. -
322
Aristotle (384-322 BC)
He was an influential Greek philosepher, and said the earth must be round. He believed in the geocentric model and the moon is closer than the sun and it also moves around the earth. -
Sep 29, 1543
Nicholas Copernicus
First to publish that the sun is the center of the universe or the heliocentric model, but it wasn't an oval, they were perfict circles. -
Tycho Brahe
He made the most accurate celestial observations of his time and challenged the prevailing belief in how the universe was organized. -
Johannes Kepler
He was Tycho's assistant and believed in heliocentrism. He used math and physics to prove Copernicus was right. He had 3 laws, Law of ellipses, Lasw of equal areas, and the Hermonic law. -
Galileo Galilei
He supported Keplers work on planitary motion. He used and improved the new telescope. -
Christiaan Huygens
He studied the rings of Saturn and discovered its moon Titan. He also invented the pendulum clock. -
Giovanni Cassini
He discovered four satellites of the planet Saturn and noted the division of the rings of Saturn. -
Isaac Newton
Newton built the first practical reflecting telescope. He studied gravity and its affects on planets and their orbit. -
William Herschel
He discovered Uranus and 2 of its major moons, and he also discovered 2 moons of Saturn. -
Eratosthenes (194 BC)
His big achievement is that he found the circumference of the earth.
