Longitude and Latitude

Educational Crap 01

Longitude and Latitude

In a song that I really loved Paul Simon says

"When I think of all the crap I learned in High School, it's a wonder I can even think at all"

I often pondered how different interests draw us into totally separate views on what knowledge is important and what is among the "crap" we were forced to learn.

For my part, I always liked maps and actually paid attention in my geography class.  One of the things you learn in geography is latitude and longitude and I expect most high school students are sure there is no possible value in such education, but I'm here to tell you that it is packed with fun facts (and on a trip like this it has real value).

In a nutshell longitude and latitude are about wrapping the planet in graph paper.  By doing this we can pinpoint anything in the world and attach an exact position that essentially says "it's this far up and down, and this far left and right".

Longitude is lines up and down that are used to measure east and west.  The two interesting things are the prime meridian (which is zero on our count to 360 degrees around the ball, and the international date line (which is sort of on 180 - opposite from the prime meridian, but does some crazy twisting and turning to avoid land).  For this trip I didn't care much about longitude (we didn't cross any of the cool stuff).

Latitude is what got really interesting as we headed toward the south pole.

Latitude is used to measure the earth from top to bottom.  It consists of rings around the planet horizontally.  The equator is the middle.  90 degrees north is the north pole.  90 degrees south is the south pole.  Here's some interesting things about latitude:

• The earth rotation has some wobble relative to the sun so the place on earth that is closest to the sun changes.
  
     > At the start of spring and fall the closest point to the sun is on the Equator
  
     > At the start of summer the closest point to the sun is 23.5 degrees north (the latitude that includes Durango, Mexico).
  
     > At the start of winter the closest point to the sun is 23.5 degrees south (the latitude that includes Santos Brazil (just south or Sao Paulo)
   
• Because of the earth's tilt summer in the northern hemisphere (north of the equator) is winter in the southern hemisphere (south of the equator).  Winter in the north is summer in the south.
   
• As you move north or south from the point on earth that is currently closest to the sun, the temperature drops because you are moving farther from the sun.
   
• There are 5 major circles of latitude.  Artic circle (66.33 degrees north), Tropic of Cancer (23.26 degrees north), Equator (0 degrees) Tropic of Capricorn (23.26 degrees south), and Antarctic Circle ( 66.5 degrees south)
   
• The tropics (area between tropic of cancer and tropic of Capricorn) houses the part of the earth that is closest to the sun (covering the wobble)
• The artic circle (66.33 degrees north) is the northern latitude where it stays light (or dark) for a full 24 hours. 
   
• The Antarctic circle (66.5 degrees south) is the southern latitude where it stays light (or dark) for a full 24 hours.
   
• Moving north or south from the spot closest to the sun changes the length of the days (summer they get longer, winter they get shorter).
   
• When we set sail, the day was 15 hours and 30 minutes long.  (assuming it got light 30 minutes prior to sunrise @ 5:49 a.m. and it got dark 30 minutes past 8:11 p.m.)
   
• When we reached Antarctica the day was 18 hours 45 minutes long (based on the same assumptions above, even though they were now false, with sunrise at 4:15 a.m. and sunset @ 10:02 a.m.)  The reason the assumptions from the previous bullet were false is because as we approached the south pole the sun couldn't get much past dusk (when it has set but hasn't dropped far enough below the horizon to stop providing light).  It was actually still light when I went to bed at around midnight because the sun doesn't get very far below the horizon.  The dark actually only lasts around 3 hours with 21 hours of light.
  
  When we started heading north again I remember there was a day when Mandy and I noticed it was dark at 11 p.m. and we thought it was strange for it to be dark that early.
   
• The south ocean (and Antarctica) starts at 60 degrees of latitude south.
   
• Mandy and I traveled south 97.62 degrees south from Dallas Texas (32.77 degrees north) to Paradise Bay Antarctica (64.95 degrees south).  This distance is farther than the distance from the equator to the north pole).
   
• The temperature dropped over 70 degrees Fahrenheit while we were on-board the ship.