Take out a map and draw a straight line from London to LA and it will go across the mid-Atlantic and cut through the middle of the US. Seems like a logical route to take.
So why, when you take a flight between the two points, do you fly over Scotland, Greenland and Western Canada?
Well the principal reason for this is that maps are flat and, as cleverly pointed out by Aristotle over 2,000 years ago, the world isn’t. So it’s a shorter distance to go up and over than around the side to get from London to LA. If you have a globe or next time you’re near one, have a look and you’ll see what we mean.
A more pronounced example of this would be a route from Singapore to New York. If you look on a globe, you will see that the route that goes via the North Pole is much quicker than the one going in an east or west direction (as would seem natural on a map). This route is called the Great Circle track and is always the shortest distance between two points on the planet.
You can find the Great Circle track between two points on a globe by using a piece of string and moving it until you have the shortest length of string between the two points.