Monday, November 29, 2021

Finding a Geographic Opposite

One evening last week my daughters were playing with the globe pillow that is featured in this blog post. They started asking questions about what each place is called and where it is relative to where we live. Answering their questions reminded me of the concept of an earth sandwich

The idea of an earth sandwich is that you find the complete opposite location of where you are in the world. Some people take to the fullest extent and actually place bread on one location then get someone in the opposite location to do the same and actually make a sandwich. I use the idea of an earth sandwich just to help kids understand how some map projections can distort their understanding of the size and shape of places. 

You can find the complete opposite location of where you are (these are actually called antipodes) in a couple of ways. The first method is to simply identify your current exact location using latitude and longitude coordinates and then use the mathematical opposites to find your exact opposite location. For some students, doing that math might be a little trick. Another method is to use the Map Tunnelling Tool


The Map Tunnelling Tool places two digital maps (ESRI maps) side by side. You then click one of the maps to identify your current location and the other map will automatically display the antipode (opposite location) for your current location.