PHYSICAL SCIENCE_4TH QUARTER

• ASTRONOMY

  • Natural Science that deals with the study of celestial objects and phenomena
  • Uses Mathematics, Physics, and Chemistry to explain their origin and evolution
• MODELS OF THE UNIVERSE

  • Early Universe
  • Geocentrism
  • Heliocentrism
  • Modern Universe
• EARLY UNIVERSE

  • THALES
  • ANAXIMANDER
• THALES

  Proposed that Earth is a disk floating on water
• ANAXIMANDER

  Suggested that Earth is a cylinder and that its surface is curved
• GEOCENTRISM and HELIOCENTRISM

  • Geocentric models assume that Earth is the center of the universe
  • Heliocentric models assume that the Sun is the center of the universe
• GEOCENTRIC MODELS

  • PYTHAGORAS
  • EUDOXUS
  • ARISTOTLE
  • PTOLEMY
• PYTHAGOREAN MODEL (PYTHAGORAS)


  • Asserted that Earth is round and that heavenly bodies move in circles
  • Considered the motions of the planets were mathematically related to musical sounds and numbers called THE MUSIC OF THE SPHERES
• EUDOXUS MODEL


  Used a series of concentric spheres on which the sun, the moon, and the planets moved in perfect circular motion while the earth is fixed at the center
• ARISTOTLE’S MODEL


  • Used buffering spheres between the celestial sphere of Eudoxus and an outermost sphere that was the domain of the PRIME MOVER
  • The prime mover rotated the outermost sphere with constant angular speed, causing the other spheres to rotate as well
• PTOLEMY’S MODEL


  • Devised a more complex epicyclic model where each planet has its own epicycle and deferent
  • Epicycle is a circle on which a planet moves
  • Deferent is the center of a small circle in turn moves around Earth along a bigger circular path
• HELIOCENTRIC MODELS

  • PHILOLAUS
  • ARISTARCHUS
  • COPERNICUS
• PHILOLAUS’ MODEL


  • Believed that neither Earth nor the Sun was at the center of the universe
  • Planets and heavenly bodies were supposed to move around a “fire” located at the center of the universe
  • His model was called Pyrocentric Model
• ARISTARCHUS MODEL


  • First one to have a heliocentric model
  • Gave a model of the universe with a stationary Sun and planets rotating in circular orbits around the Sun
• COPERNICUS’ MODEL

  • Nicolaus Copernicus is considered as the father of modern Astronomy
  • Asserted that Earth spins on its axis everyday and revolves around the Sun just like other planets
  • His model was not initially accepted because of its inconsistencies with Aristotelian mechan
• Nicolaus Copernicus is considered as the father of modern Astronomy
• Copernicus' Model

  • Earth spins on its axis everyday and revolves around the Sun just like other planets
  • Not initially accepted because of its inconsistencies with Aristotelian mechanics
• Greeks' categorization of motion

  • Terrestrial Motion - motion of any object on Earth
  • Celestial Motion - movement of any object beyond Earth
• Tycho Brahe's Model

  • The Sun orbited around Earth, while the other planets orbited the Sun
• Galileo Galilei is the inventor of the telescope
• Galileo's observations with the telescope

  • The moon has mountains, valleys, and craters
  • The surface of the Sun has sunspots
  • Jupiter has four moons
  • Venus has phases similar to those of the moon
  • Many stars too faint to be seen by the naked eye
• Johannes Kepler's contributions

  • Served as an assistant to Brahe
  • Inherited data on planetary motion from Brahe
  • Three Laws of Planetary Motion: Law of Ellipses, Law of Equal Areas, Law of Harmonies
• Law of Ellipses

  1. Planets move in ellipses having a common focus situated at the Sun

  2. Perihelion - closest point to the sun

  3. Aphelion - farthest point from the sun
• Law of Equal Areas

  1. Planets cover the same area of space in the same amount of time no matter where it is in its orbit

  2. The planet moves fastest at the perihelion and slowest at the aphelion
• Law of Harmonies


  1. Planet's orbital period is proportional to the size of its orbit

  2. Period - time it takes to make one complete revolution around the Sun
• Earth rotates on its axis. One rotation is equivalent to 23 hours, 56 minutes, and 4 seconds
• Earth revolves around the Sun. One revolution is equivalent to 365.25 days
• Zones of the Solar System

  • Innermost - occupied by terrestrial planets (Mercury, Venus, Earth, Mars)
  • Asteroid Belt - occupied by leftover rocks from the formation of planets
  • Realm of Giant Planets - occupied by gaseous planets (Jupiter, Saturn, Uranus, Neptune)
  • Kuiper Belt - occupied by small celestial bodies (dwarf planets)
• THALES :

  
• ANAXIMANDER :

  
• GEOCENTRISM AND HELIOCENTRISM

  
• PYTHAGOREAN MODEL :

  
• EUDOXUS MODEL

  
• PTOLEMY'S MODEL

  
• PTOLEMY'S MODEL

  
• ARISTOTLE'S MODEL

  
• PHILOLAUS' MODEL

  
• ARISTARCHUS MODEL

  
• COPERNICUS' MODEL

  
• TYCHO BRAHE