• Only need to recognize Orion and the Big Dipper
  • Constellations
    • You can use the Big Dipper to find Polaris
  • Angular size, distance, separation
    • Apparent size measured in degrees (or radians)
    • Object in sky stretching from your zenith to the horizon would have an angular size of 90˚
    • Angular separation between setting Sun and the Moon overhead is 90˚
  • Apparent motion of the stars
    • Star motion impossible to see on a daily basis because they are so far away
    • Perpendicular to the horizon --> equator
    • Parallel to the horizon --> North Pole
  • Early Greek and Roman cosmology
    • What they knew ~2500 years ago
    • Earth was a sphere
      • Shadow shape, changing stars as you move south
    • Sun is farther from Earth than the Moon
      • Eclipses
    • Stars seem to slowly move in regular pattern
    • Thought Earth was stationary (they were wrong but moving in the right direction)
    • Ranking system for magnitude of stars
      • Based on brightness


  • Goals
    • Distinguish among categories of numbers
    • Describe positional notation
    • Convert numbers in other bases to base 10
    • Convert base-10 numbers to numbers in other bases
    • Describe the relationship between bases 2, 8, and 16
    • Explain the importance to computing of bases that are powers of 2
  • Convert binary --> decimal
  • Convert real decimal --> binary
  • Perform binary addition/subtraction
  • Two's compliment
  • Number Theory
  • Grace Hopper