Ancient Greek Physics and Astronomy PDF

LESSON 1: ANCIENT GREEK PHYSICS AND ASTRONOMY LEARNING COMPETENCY Explain how the Greeks knew that the Earth is spherical (S11/12PS-IVa-38) OBJECTIVES 1. Recognize the Greek philosophers who proposed that the Earth is spherical. 2. List the naked-eye astronomical proofs that th...

LESSON 1: ANCIENT GREEK PHYSICS AND ASTRONOMY LEARNING COMPETENCY Explain how the Greeks knew that the Earth is spherical (S11/12PS-IVa-38) OBJECTIVES 1. Recognize the Greek philosophers who proposed that the Earth is spherical. 2. List the naked-eye astronomical proofs that the Earth is round or spherical. 3. Understand ancient Greek two-domains view of the universe.  WHAT DO I NEED TO KNOW? a. What is the shape of the Earth? b. What causes the movement of the celestial bodies? c. Who first proposed that the Earth is not flat? d. What are the proofs that the Earth is not flat?  Science is defined as “a collection of known truths about the Universe that develops and expands over time.” Thus, science is dynamic and ever- changing. It develops when better models are found, clearer and more useful mechanisms are used to explain a group of phenomena, more accurate and precise details are observed, and many more. Therefore, astronomy is a major influence on the development of Physics. That is why we discuss ancient Greek philosophy, cosmology, and astronomy. The Greeks divided the universe into domains, the celestial domain, and the terrestrial domain. In this module, the learners are expected to get to know these philosophers and their contributions to physics.  ACTIVITY CARD 1 Directions: Label the following pictures. Choose from the sentences in the box.  DISCUSSION OF ACTIVITY Have you ever wondered what the early philosophers thought about the shape of the Earth? The shape of the Earth is oblate spheroid. It has a bulging equator and squeezed poles. Around 500 B.C., most Greeks believed that the Earth was round, not flat. It was Pythagoras and his pupils who were first to propose a spherical Earth.  In 500 to 430 B.C., Anaxagoras further supported Pythagoras' proposal through his observations of the shadows that the Earth cast on the Moon during a lunar eclipse. He observed that during a lunar eclipse, the Earth's shadow was reflected on the Moon's surface. The shadow reflected was circular.  Around 340 B.C., Aristotle listed several arguments for a spherical Earth. The North Star was believed to be at a fixed position in the sky. However, when the Greeks traveled to places nearer the equator, like Egypt, they noticed that the North Star is closer to the horizon. Aristotle argued that if the Moon and the Sun were both spherical, then perhaps, the Earth was also spherical.  If the Earth was flat, then a ship traveling away from an observer should become smaller and smaller until it disappeared. However, the Greeks observed that the ship became smaller and then its hull disappeared first before the sail as if it was being enveloped by the water until it completely disappeared. If you stick a stick in the ground, it will produce a shadow. The shadow moves as time passes. If the world had been flat, then two sticks in different locations would produce the same shadow.