Latitude and Longitude (geographic grid system)
- How would you describe a location on a ball?
- Greeks - localized grid system for round world!
- latitude - also known as "Parallels"
- angle from center to poles (fixed unlike
ball)
- Greeks used crude sextant and stars (300 B.C.)
- one degree divided into minutes and seconds
- about 69 miles per degree
- longitude - also known as
"Meridians"
- historically difficult to measure rate without time piece and reference
point
- measured knots on a rope
- needed long-term solution to calculate rate away from land
- 1759 the first timepiece able to keep time at sea!
- 1884 establish universal starting point for longitude
