PHYSICAL SCIENCE REVIEWER

• Celestial Domain


  The Celestial domain is perfect hence can only be made up of the perfect substance they called "ether" and can only move in perfect motion: circular in path and constant in speed
• Terrestrial Domain


  The terrestrial domain objects are imperfect and that the tendency of things to attain perfection is the cause of their motion
• Diurnal/ Daily motion of the sky


  The appearance that the objects in the sky moves relative to the Earth's local horizon (celestial objects: moon, Sun, stars, planets; there were only five known planets: Mercury, Venus, Mars, Jupiter, Saturn) as observed for one whole day at the same location on Earth
• Annual motion of the sky


  The appearance that objects in the sky moves relative to the background stars as observed at the same time of the day and at the same location on Earth
• Pythagoras


  • Universe is mathematical; mathematics as the best way to express truth about the Universe; Sun, moon and Earth are spherical; placed Earth as the center of the Universe
• Plato


  • Attainment of perfection as absence of change; celestial spheres being crystalline and contains the moon, the Sun and the stars; explaining the shadows — read on Plato's Allegory of the Cave and the Allegory of the Divided Line — as his description or framework on how to look at the Universe, in particular that the daily and annual patterns of the sky must have a greater reality besides its appearance
• Eudoxus


  • Followed previous models of the universe but added auxiliary spheres to provide appropriate tilt to the planets' path
• Aristotle


  • Two-domain system with terrestrial domain containing four elements that tries to attain perfection by being in their natural location relative to the center of the Universe: the center of the Earth. He was a learner of Plato
• Thales


  • Famous for discovering why eclipses happened and that could predict them
• There are no books or writings that have survived from Thales
• Anaximander


  • Great early philosopher, better known for his ideas about evolution, was the first Greek philosopher to create a cosmological model; believed that the earth was cylindrical in shape, and imagined it to be surrounded by air and then fire, 'like the bark of a tree'
• Pythagoras


  • He thought that the universe could be explained with mathematics; He was also the first ancient astronomer to suggest that there was a harmony of the spheres, and that the movement of the planets, sun, moon and stars could be described by whole numbers and mathematical precision
• Empedocles


  • He devised the theory that all substances are made of four pure, indestructible elements: air, fire, water, and earth
• Plato

  • Proposed that the stars formed the outermost crystal sphere, followed by the planets, the sun, the moon, and the spherical earth at the center
• Eudoxus


  • Envisioned the universe as containing the static earth at the centre, with the stars occupying the outermost crystal sphere. The sun, inside this sphere, rotated around the earth at the same speed as the stars
• Eratosthenes


  • Librarian at the Great Library of Alexandria in Egypt; Developed a calendar with a leap year; Measured the circumference of the Earth in 325 BC
• Hipparchus


  • Considered the first great astronomer and scientist; He used his trigonometric methods to calculate eclipses of the sun and moon
• Ptolemy


  • The most influential astronomer in his day and a great admirer of Hipparchus; Great proponent of the geocentric model
• Aristotle


  • Founded his own school called the Lyceum in Athens; One of the first to attempt to create a scientific model of the universe; This model has now become known as the "Geocentric Model" which places the "imperfect" Earth at the center and all of the "perfect" celestial objects go around us in perfect circular motion
• Aristarchus


  • Teacher of the better-known Archimedes; The first to attempt to measure the relative distance between the Earth-Moon and the Earth-Sun without the aid of trigonometry
• Ptolemy's model of the Universe


  Considered refined than previous geocentric models because his model could explain the motion of the celestial bodies accurately
• Aristarchus of Samos


  • He was a Greek astronomer who made the first attempt to create a heliocentric model of Universe, which places the sun and the fixed stars were at rest, while Earth revolved around the sun in a circular path
• Nicolaus Copernicus


  • During the 16" century, a Polish astronomer, revived the heliocentric model of Aristarchus; He was hesitant to publish his findings because he was afraid of condemnation; Copernicus strongly believed in the heliocentric model because there were loopholes in the Ptolemaic model in terms of predicting the positions of the Planets
• Copernicus's Model of Universe


  Heavenly bodies exhibited constant circular motion along their epicycles; The sun was at the center of the Universe; The order of planets is Mercury, Venus, Earth, Mars, Jupiter, Saturn and beyond the planets were fixed stars
• Tycho Brahe


  • Danish Astronomer made some of the most accurate ever observations with the naked eye in the late 16th century; He disproved aristotle's concept of unchanging universe when he saw a new star in constellation of cassiopeia in 1572; His model of the universe was both helio and geo centric with the planets revolving aroun the sun
• Johannes Kepler


  • Produced an improve heliocentric model of universe, his model stated that the planets revolve around the sun in ellipses not circles and with the sun located at anyone of two foci in those ellipse
• Law of Ellipse


  The orbit of each planet about the Sun is an ellipse with the Sun at one of the foci of the ellipse
• Law of Equal Areas


  The line joining the Sun and the planet (called the "radius vector") sweeps over equal areas in equal times as the planet travels around the orbit; This law implies that planets actually speed up as they go nearer to the sun
• Law of Period


  The square of the period of revolution (time for one complete orbit) of a planet around the Sun is proportional to the cube of the average distance of the planet from the Sun; The Law of Period being related to the average distance of the planet from the Sun marked the conclusion that there is a certain kind of harmonics in the Universe
• Tycho Brahe Model of Universe


  Earth was at the center, the sun, and the moon revolved around it and all other planets orbited the sun. Such a model was a type of "geoheliocentric system"
• Models of Solar System

  • Geocentric Model
  • Heliocentric Model
  • Geoheliocentric Model
• Rumulus

  The Legend and Founder of the Rome; The original calendar is consisted only of 10 months and of a year 304 days; After the Greek lunar calendar the Roamn ruler Numa Pompilius is credited with adding January and February at the end of the calendar to create 12 month year