Offshoreonly.com - The Real Speed You Read On A Gps !!!!!!!!!!

My good friend Spock and I were having a few Romulan Special Brews last night on the Starship Enterprise, and beamed Dr.Werner Von Braun aboard...who just happened to be passing by. He joined us for a few sips...and I brought up the subject of what a GPS really reads.

Von Braun, made it very clear to us about the reading on a GPS in relation to a boats position and speed on the Earth (water). He said...since the earth is about 25,000 miles (40,075.036 kilometers, exactaly) at the equator, and it rotates one revolution in 24 hours...if you were to hang above the surface of the Earth at the equator, without moving, you would see 25,000 miles pass by in 24 hours, at a speed of just over 1,000 MPH. The Earth is also moving around the Sun at about 67,0000 MPH.

An object at one of the Poles, has hardly any speed at all due to the Earths rotation. A spot on a rod one centimeter in circumference for example, set verticaly in the ice, exactaly at a Pole would have a speed of one centimeter per day. Therefore, if you were boating at the equator, and your GPS read 100 MPH, you are in reality, actualy traveling at 1,100 MPH. But if you were boating at one of the Poles...you would hardly be moving at all, no matter what that stupid GPS reads.

Your true speed, due to the rotation at any other point on the Earth, can be calculated by multiplying speed at the Equator by the cosine of the latitude of that point. If you are not familiar with cosines, I wouldn't worry about that now, but if you can find a pocket calculator that has a cosine button, you might like to try taking the cosine of your own latitude and multiplying that by the rotation speed at the Equator to get your own current speed during rotation. Otherwise, JUST BELIEVE WHAT THE DAM GPS READS...and leave it at that.

By the time he was finished his explanation...we were all pretty stonned. He really likes to talk (but he did have some good weed). I'm still trying to remember how he left us....I'm pretty sure he was on a sled pulled by at least a dozen....I think...moose....they must have been...moose...HUGE ANTLERS! :drink: :drink: :drink: r.