PHY SCI

• EARTH IS ROUND


  Pythagoras and his pupils
• the shadows that the earth cast on the moon during lunar eclipse was supported by


  Anaxagoras
• Contributed on the arguments for a spherical earth which include the positions of the North Star...


  Aristotle
• During a _ the Earth casts a circular shadows on the moon


  lunar eclipse
• who observed the lunar eclipse


  Pythagoras
• was the first to give an accurate measurement during his time


  Erastosthenes
• this when the moon is between the Sun and the Earth. The Sun is blocked by the moon


  Solar Eclipse
• occurs when the Earth casts its shadow on the moon when the Earth is between the sun and the moon


  Lunar Eclipse
• -the two points where the ecliptic intersects the celestial equator.


  Equinoxes
• stars appear to be attached to a celestial sphere that round the axis


  Motion of the stars
• Early the astronomers discovered that Mercury, Venus, Mars, Jupiter, and Saturn are planets.


  Visibility of Planets
• What are the phases of the moon? 


  New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Crescent
• Waxing (Gibbous,Crescent) means?


  Increasing
• Waning means?


  Decreasing
• • was a Danish astronomer 


  Tycho Brahe
• Through the help of his inventions and his assistants, he was able to study the solar system extensively and was able to accurately determine the position of  stars.


  Tycho Brahe
• Emperor Rudolf II recommended _, a German scholar, as the assistant of Brahe.


  Johannes Kepler
• The planets move in _ having a common focus situated at the sun. The other focus is empty


  Law of Ellipse
• The closest point to the sun in a planet’s orbit is the 


  perihelion
• the farthest point is called the 


  aphelion
• According to this law, the planets move around the sun in such a way that a line drawn from the sun to the planet sweeps out equal areas in equal intervals of time.


  Law of equal areas
• It states that the ratio of the squares of the periods of two planets is equal to the ratio of the cubes of the average distances of these two planets from the sun. 


  Law of harmonies
• is the time it takes to make one complete revolution around the sun.


  Period