NavList:

Go to Google Maps and reduce the scale until you can see most of the Earth.  Greenland is massive c.f. Central Africa.  From this I conclude that the Google Maps projection is close to standard Mercator’s.  Find a scale which includes Boston MA and London, England.  Place the arrow over Boston and left click.  Then right click to get a menu box, and left click “Measure distance”.  Move the arrow to London and left click.  You’ll find the distance is 5261km, but the line drawn is a beautiful arc looking very like the great circle.  Now, just for fun, go to Google Satellite without changing scale.  You’ll find you’ve got a “Globe” presentation, which you can tilt until the line between Boston and London is straight while the distance remains constant.  You would appear to have hit the view in with the plane of the great circle.  My question is, is it a simple matter for a computer mathematician to create such presentations, or is it really clever stuff?  Also, is there any way, just for fun, you could use Google maps to solve the PZX triangle to get Co-Alt, or would it take too much effort to work out the lat & long of X? DaveP