PHYSICAL SCIENCE

• PYTHAGORAS с. 570-с. 495 BC

  
  

  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.
• Plato с. 427 с. 347 BC He was the student of Socrates. 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.
• Aristotle • 384 BC to 322 BC

  -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
• Thales About 624 BC to 547 BC

  
  

  Famous for discovering why eclipses happened and that could predict them. There are no books or writings that have survived from Thales.
• ANAXIMANDER с. 610-с. 546 -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.
• Empedocles -492 BC-432 BC He devised the theory that all substances are made of four pure, indestructible elements: air, fire, water, and earth.
• Eratosthenes - 0276 BC to 194 BC • 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 - 190 BC to 120 BC considered the first great astronomer and scientist • He used his trigonometric methods to calculate eclipses of the sun and moon.
• Ptolemy -About 85 AD - 165 AD

  -The most influential astronomer in his day and a great admirer of Hipparchus - Great proponent of the geocentric model
• Aristarchus • About 310 BC to 230 BC - 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.
• Before the telescope was invented, ancient astronomers only used their unaided eyes to observe the sky and the stars. Eventually they created basic models of the universe.
• Plato's Model of Universe • The Universe is consists of crystalline spheres containing Moon, Sun and the five planets (Mercury, Venus, Mars, Jupiter, and Saturn) • The stars are fixed in the outermost crystalline sphere that rotates annually.
• Eudoxus of Cnidus

  • He found out the differences in the motion of each planet should be considered to give an accurate description of the Universe.
• Aristotle's Model of Universe

  • Other celestial bodies were built up symmetrically in concentric spherical rings around the Earth.
• Astrolabe

  - An instrument that once was the most used, multipurpose astronomical instrument. • Two-dimensional model of the celestial sphere. • The name has its origins from the Greek words astron and lambanien meaning "the one catches the who heavenly.
• 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 Model Of Universe - Create a heliocentric model of Universe - Earth was spherical

  -It is far from the sun

  -Moon passes through the Earth's shadow when they align.
• Nicolaus Copernicus (1473-1543) - During the 16th century, a Polish astronomer, revived the✩ heliocentric model of Aristarchus. - He was hesitant to publish his findings because he was afraid of condemnation. But later on, it was published a year before his death.
• Tycho Brahe (1546- 1601) In Brahe's model of the universe, called "Tychomic System", 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"