Wednesday, September 26, 2007

Map Projections

Tonight we had out first test, talked about Mary, who wasn't in class, and learned about Map Projections. Actually, we didn't talk about Mary who was out sick and I hope she feels better so she can come back and take the test. The test seemed like a fair assessment of our progress through the first four chapters.

To prepare for the test, I spent a lot more time in the textbook, and am really beginning to appreciate it. I love good technical writing, and this book is pretty good. The older Bentley repair manuals for various VWs I've owned over the years were great reading. They had these really well written paragraphs describing the functioning of the fuel injection system or something else complex, which made it understandable. Nowadays there is so much complexity in the cars, which requires so much volume of information that they don't have space for such frivolity.

The Map Projections are pretty interesting. No matter what mathematical method you use to translate a sort of sherical shape (the Earth) onto a flat surface (a map), you are going to have some sort of distortion. The most disturbing distortion to me is distortion of shape. The most common projection we have seen since we were kids is the Mercator projection. It is really handy for sailing ships on the ocean because you can draw a straight line from your location to your destination and just sail on that compass heading. The Mercator really isn't so good for showing accurate relationships of the size of features at various latitudes though. It shows Alaska about the same size as Brazil, which is actually 5 times larger. Being a very visual thinker, I am now in crisis because the pictures I have in my head of the world may be all wrong. ALL WRONG! OMG.

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