Occam's Razor

For as long as I can remember, maps have fascinated me. This may have come from not having a very adventurous childhood. Our vacations, when they happened at all, rarely occurred more than a few hundred miles from home. I never took a commercial airline flight until I was an adult. However, we did have an oversized National Geographic atlas of the world. It was a good way to visit faraway places in my imagination.

I was fortunate enough for a while to work for what was then the Defense Mapping Agency. While I had no training in cartography, I did earn a modest living tracking the printing of various topographic maps and nautical charts used by the military. It was neat to watch the process, from the careful correction of negatives (generally one for each map color) to seeing the map roll off the presses. I left that job more than twenty years ago, and since that time the Defense Mapping Agency has changed names a number of times and now probably produces far more digital products than printed products. For about four years, I was in map heaven. Trying to better track the production of maps lead me into a career in the information technology field that has since kept me well moneyed. Yet, my interest in maps never waned.

So naturally, I was quite agog when Google Earth was introduced in 2005. Who needs television when you can play with Google Earth instead? Since then, the product has gotten progressively better and their street views left me euphoric. Nevertheless, even a product as mature as Google Earth has some limitations. Want to plot a great circle route? There is no way to do it. Want to draw concentric lines around a point on the globe? Here again Google Earth falls short.

Most people don’t want to do these things, but I do. My frustration eventually turned up the GPS Visualizer site, a small work of wonder by itself, as it is a creation of one man, specifically Adam Schneider, who must also have my mapping bug. You can do all these things and more on the GPS Visualizer site.

Great circle routes fascinate me. In case you are not familiar with the term, this is the shortest distance between two points on the earth. The shortest path is not what you would think looking at your typical Cartesian map. You can sort of figure it out if you have a globe with a piece of string, but what you get is an approximation. In the northern hemisphere, trips to anywhere in Europe are typically flown far north of where you would expect them to fly. This is good. It saves the airline a lot of gas. Since the earth is not a perfect sphere, there are some minor errors in most calculations. Schneider has figured it all out and can produce extremely accurate Great Circle routes.

One of the things I like to do is draw great circle routes between far-flung airports. The routes airlines actually fly often differ quite a bit from great circle routes, mainly because in the United States the FAA designates that flights must follow standard routes. Still, you can get a good idea of your flight path by creating its great circle route. For fun, I tracked one of the more unusual flights I took, between JFK International in New York City and Narita airport in Tokyo, Japan. My flight was a bit south of the great circle route because at the time, the Soviet Union still existed and they were known to shoot down foreign aircraft that wandered into their air space. In addition, not all aircraft are certified to fly above the Arctic Circle. The great circle route for this flight though would scrape the top of the Bering Sea and pass over Vladivostok. Sadly, I remember little but clouds approaching Japan, but I only had the vaguest idea of where I was. In nearly fourteen hours in the air I looked down at a lot of frozen tundra while the sun hung largely in the same position in the west. It was disorienting, weird and wonderful, almost like being in outer space.

The GPS Visualizer site does lot of other neat geographic tricks. You can create a great circle map between any two points if you want, not just airports. You can type in two addresses and it will tell you the exact distance between them and give you an exact compass heading should you want to hoof it. It will draw elevation maps between two points. You can draw rings around a point at given distances. You can see the results in Google Earth by downloading the .kmz file it creates. You can also see it in Google Maps or get it in SVG, PNG and JPEG formats.

One thing I am discovering it that despite having over six billion people on the planet, most of our planet’s landmass is thinly populated. Last night as an experiment, I used the GPS Visualizer to draw lines exactly north and south of my house going ten thousand miles. I got the coordinates of my house out of Google Earth. I was curious who might be living one hundred, one thousand or five thousand miles due north or south from my house.

The answer: hardly anyone, except in the United States and even then, not that much. Five hundred miles south of my house is a point that looks like it is in the Bermuda triangle. At my longitude, the line cuts through Panama, but not through any populated places. It tracks through the Andes Mountains then disappears into the vastness of the Pacific Ocean. I then tracked it north. It came close to Rochester, then traveled over forests in Ontario, out into the tundra, over the pole, over Russia and Mongolia and did not hit anything resembling civilization until it reached Thailand. Even so, I hit no major cities.

Ideally, Google would put all these features into Google Earth. Perhaps some day they will because as good as the GPS Visualizer site is, it is just one guy having fun so it is a bit awkward to use at times. Still, to a man fascinated by maps like me its power combined with Google Earth give me a neat way to geek out. Try it out sometime. You may end up like me finding it oddly entertaining.