The shortest route between two points is, of course a straight path. But, if you've ever looked at the information screen on a long-haul flight, then you'll have noticed that your flight is doing something very different.
The reason why flights take curved routes, especially over long distances, is all down to maths and physics.
The spherical shape of the Earth means it's more bulbous in the middle and slimmer towards the poles; A 'curved flight' can cut the distance to a destination and the time you spend crammed into your seat next to the 300 fellow travellers.
These curved flight paths not only help conserve fuel but also allow airliners to take advantage of 200mph jet streams, exploiting what's known as, the Great Circle Route.