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Period: 276 BCE to 195 BCE
Eratosthenes
His discovery is finding the circumference of the Earth and calculating the tilt of the Earth's axis, around 240 BC. These two discoveries are very important because it helps find the weight and mass of the Earth through calculations. -
Period: 90 to 168
Claudius Ptolemy
He created the Ptolemaic system, which is similar to what we know about the geocentric theory. It's where Earth is the center of our universe. He studied stars movement and used geometry to predict the movements of the planets, known as Almagesti. He also discovered that planets move in small circles as epicycles. Today, all his studies have been proven incorrect. However, these discoveries/creations are important because it gave us the first model of the solar system. -
Period: 1473 to 1543
Nicolaus Copernicus
He discovered that all the planets, including Earth, revolved around the sun. He officially announced the heliocentric theory in 1510. This discovery is very important because it is the correct theory and basis of our solar system today. -
Period: 1546 to
Tycho Brahe
He created a physical representation of the sky that allowed him to develop celestial maps of planetary movement in 1572. He created many instruments to observe the stars and planets better, before the telescope was invented. He wanted to create his own picture of the universe. These creations are important because his studies allowed/helped Kepler form the three laws of planetary movement. -
Period: 1571 to
Johannes Kepler
Kepler discovered the three laws of planetary motion in the early 1600's:
1. Planets move in elliptical orbits
2. Planets sweep out equal areas in equal times
3. Squares of time to complete one orbit are proportional to cubes of distance from sun
This discovery is important because it explains much of the movement in our solar system. -
Period: to
Sir Issac Newton
Newton discovered the laws of gravitation and the laws of motion around 1687. This discovery is the most important because it basically explains to us the physics of Earth, and how we move and don't move. -
Period: to
Albert Einstein
Around 1905, Einstein discovered physics. Most importantly, he discovered that everything was made up of atoms. This is so important because we were able to actually discover atoms and what made up atoms.