And the most obvious point of evidence why this is not the case, is that it is not summer, when it is summer at one point on the planet, it is not summer throughout the planet at that time in particular when it is... (let me draw our planet) in particular, when it is summer in the northern hemisphere, (actually let me do summer in a more warm color) when it is summer in the northern hemisphere, so here it is summer, it is winter in the southern hemisphere.