Google Maps resolution

Jessica and Spencer are gone for a couple weeks, so naturally I went to work on useful, important things.  Here’s a perfect example of this.  It occurred to me that any digital map can only map a certain number of pixels.  Stated differently, every pixel on the screen can only have one point on the map related to it.  This can be illustrated by hovering your mouse over a map at http://maps.google.com.  The point at which your mouse is hovering is one exact longitude/latitude combination.  The interesting thing I discovered, at least for myself, is that every scale of “zoom” (Google has 19), will have less latitude/longitude coordinates to map as you zoom out.  The most zoomed-in level can map more coordinates per pixel than the most zoomed-out.  This is assuming that your screen could show the entire image of the zoom level, a high standard for level 1 zooming (only fit a 1/4 mile stretch on my screen).  The most zoomed out image shows the entire Earth in about an 1/8th of my screen.

Ok, so here’s the REALLY interesting part.  It turns out that the pixel-to-coordinate resolution at the level 19 zoom (most zoomed-out) comes out to each pixel being 30 miles away from each other horizontally and 80 miles vertically. What this means is that at level 19, a whole 2400 square mile expanse is represented by one single latitude/longitude coordinate.  What is MOST interesting is that it is always the same (at least on Google Maps).  For my house and almost all of Oklahoma City, we all resolve to 35.460670, -97.031250, somewhere east of the city. Here’s the link to the spot:  Adam’s Level-19 Coordinate.  The home I grew up in Sugar City, Idaho resolves to a spot in the Targhee National Forest just north of Fall River about a 1/4 mile from the Wyoming/Idaho border.

What’s yours?  Just hover your mouse over your house on Google Maps, zoom all the way out, and then all the way back in without moving your mouse. Right click, click on “What’s Here”, and it will post the address or coordinates.

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