Chapter 3 defining units of measure Flashcards
(7 cards)
1
Q
Ptolomy
A
The Greek philosopher Ptolomy plotted latitude on a map as degrees north from the equator as did many others
2
Q
On land
A
longitude can be determined through astronomical observations and surveys (still hard to do)
3
Q
On sea
A
longitude requires a clock to measure time as well as the measurement of the positions of celestial objects (e.g. Sun)
4
Q
The challenges
A
Earth rotates 360° per day or 15° per hour
5
Q
About the earth
A
You find longitude with stars and a clock
6
Q
Chronometers
A
These early clocks were called chronometers
7
Q
Prime meridian
A
was designated to pass through the Greenwich Observatory in England and is our 0° longitude line.
