How Do Planets Move? 1 We know that the Sun is at the centre of the solar system Eight planets orbit it 2 However, this has not always been believed! 3 These people all believed different things about the solar system. Firstly, when do you think Place them on the timeline these civilizations/people lived? alKatabi Aristotle Ancient Egyptians Plotemy alHazen Tusi Ancient Indians Early Humans Us in 2020 4 For thousands of years, people believed that the Earth was the centre of the solar system. By observing the Sun, during the day, it seemed obvious that it was moving around planet Earth. Early Humans Plotemy Ancient Indians Ancient Egyptians Aristotle 5 Ptolemy’s model became the accepted view for hundreds of years. However, during the time of the Islamic Golden Age, some scientists started to criticise his model. Alhazen was the first to outright disagree with the Ptolemaic Model. Plotemy alHazen 6 Other Islamic scientists explored the idea of heliocentrism. However, Tusi was the first real scientist to propose the Heliocentric Model (what we believe today!)... alHazen Tusi ? To be continued (next lesson)... 7 Activity WALT understand the geocentric model of the solar system Can you draw a diagram to show the geocentric model? Can you summarise the key people who were involved in creating this model of the solar system? 8 Firstly, let's ensure that we remember/can say the name... WALT understand the geocentric model of the solar system What does this What does the root word prefix mean? mean? Geo- is a prefix derived in or at the from a Greek word centre; meaning "earth" central. 9 Let's practise saying it... say it high say it loud geocentric whisper it clap the syllables 10 Plenary What does geo mean? What does centric mean? Which civilisation was first to believe in the Sun orbiting planet Earth? Why? Who first refuted the geocentric theory? 11.