Tuesday, April 15, 2008

Illustrating Scale

One of the joys of Google Earth is that places that people don't know much about like the poles are suddenly one click away ('One Click to The World' would be a great advert tag line for GE). I think part of the problem with communicating global warming has been that most people in the west don't have to cross a glacier to get to the shops or see the smoke from the burning rainforest when they get up in the morning. But with a virtual globe, you can fly there in a trice (you don't even have to click your heels 3 times, just once on the mouse is enough).

Scale Problem: The problem with showing remote regions of our planet is that people sometimes fail to grasp the true size of such areas, especially if you live on a crowded little island full of history and people like I do (the UK). A common way of dealing with this in text books is to show outlines of other countries for comparison. There's no reason they can't be used in GE too, I used one in my talk to UK school kids just the other day to give them a sense of the size of the North USA and Canada*. I think there should be more use made of them, especially in introductory sections of Google Earth projects.

HowTo: To produce the file I took a screenshot over the UK with the latitude longitude lines of GE turned on. I then cropped the image and added as an overlay. To get the size right I made sure the latitude lines (which are evenly spaced apart all over the globe) lined up, i.e. I sized the map so that 5 degrees of latitude on my overlay lined up with 5 degrees on Google Earth. To make it even clearer, I drew a polygon line around the coast of England/Scotland/Wales, gave it an elevation then turned the original overlay off.

*which isn't to say these areas are remote, its just UK school kids won't grasp the scale they are looking at.

1 comment:

Rich Treves said...

Later: A perfect example