HW2

• Copernicus and Galileo


  Believed the Earth is not motionless at the center of the universe, but one of the planets that orbits the Sun and rotates on its axis
• Galileo


  • Believed in the importance of experimentation and the application of math to the things he observed, unlike the Greeks
• Zodiacal constellations


  Constellations that intersect with the ecliptic, the Sun's apparent annual path through the sky
• From Earth, the Sun appears to move through the zodiacal constellations, but not the other constellations
• The stars are too far away to observe parallax without a telescope
• The Copernican model still assumed the planets moved with uniform circular motion
• Three lines of evidence that argue against the validity of astrology


  • There are no known forces that could explain why the positions of planets should affect a person's personality or fate
  • The dates that supposedly correspond to a person's birth astrology sun sign have shifted significantly since the first astrological charts, and no corrections or adjustments have been made to the predictive methods, implying that they are not logical or true
  • Statistical tests of astrology, such as seeing whether people in certain occupations were born in just one or two sun signs, show that people are distributed randomly in their astrological characteristics
• If you were to drive north from your hometown

  The altitude of the north celestial pole in the sky would be even higher
• Galileo discovered that Jupiter has moons orbiting around it, proving that not everything in the sky orbits the Earth
• Calculating the Moon's period

  1. speed = distance/time

  2. time = distance/speed

  3. time = 360°/0.55°/hr = 654.5 hr

  4. 654.5 hr/24 hr/day = 27.3 days
• The "Dark Ages" according to the English Heritage organization

  400 - 1066 AD (or CE)
• Dark Ages


  The Medieval Period, which a 14th century Italian humanist named Petrarch thought was dark because his society was moving backwards from the achievements of ancient Greece and Rome
• The Dark Ages should only refer to two centuries, from 400 to 610 AD (or CE), according to historian Alban Gautier