How Many Lines?

[Charlie]

For those of you who were looking for a thread on cocaine this will disappoint you. He he he. What I am talking about is the significant lines on a globe. I have been known to study those lines for hours. My kids just say "Oh No." When I start to talk about them. I usually just shut up then. But I really like those lines.

The Tropic of Cancer, The tropic of Capricorn the Equator, The international Date Line, the Prime Meridian, and (less appealing to me) The Artic Circle and the Antartic Circle.

How many of these lines have you crossed? How did you cross them? How many do you want to cross?

By sailboat I have crossed the tropic of Cancer at least 8 times. The latest was on the way to Cabo San Lucas during the Baja Ha Ha and then again as I brought the boat up to La Paz Mexico I crossed from S to N.

By Sailboat I have crossed the equator, The International Date line and the Tropic of Capricorn once each. All of these occurred in 1987 on a Pacific Puddle Jump that went from Manzanillo Mexico to Sydney Australia.

The Prime Meridian I have walked across while in England in 1979 (arrived by plane).

As a life goal or a bucket list I would like to sail across all of these lines except the artic and antartic circles on my own boat. I have accomplished 20% of my goal.

[nigheandonn]

Hi Charlie,
How thick is a line?
How arbitrary are they ie the prime meridian could have gone through Paris rather than Greenwich?
Is it not just a grid we have superimposed by convention on our little globe?

( Ido like to aspire to knocking them off as well!)

[Charlie]

The lines are actually not arbitrary. (Except the Prime Meridian) The tropics were determined by the point where the sun would be overhead exactly 90 degrees on the first day of summer. Here is the definiton according to Wikipedia "Because of the tilt of the earth's axis of rotation relative to the plane of its orbit around the sun, the sun is directly overhead the Tropic of Cancer on the first day of summer in the Northern Hemisphere. It is the northernmost latitude at which the sun reaches 90 degrees above the horizon at its zenith, with the Northern Hemisphere tilted toward the sun to its maximum extent."

[Kirok]

There're traditional names/ceremonies for these kinds of things in the Navy-- If you've crossed the Equator, you're a "Shellback". See Line-crossing ceremony - Wikipedia, the free encyclopedia or Crossing the Equater USN Ancient Order of the Deep Royal Order of Shellbacks