I may be being a bit thick here, but when I was a teenager I spent a lot of time travelling, and one of my trips took me to Alaska via the old Soviet Union, Eastwards from France (where I had arrived in Paris after flying South East from Scotland), through Europe. From Alaska I flew South East to Canada, and then East again home to the UK.
Surely this wouldn't be possible, to travel in the same general direction (East), and both depart and arrive in the UK (without turning Westwardly back on myself) unless the World was spherical.