Description
Common arguments against prior designs are the following: too simple, too complex, meaningless or too meaningful.
So here's a design that came to me yesterday that hopefully offers a viable chance of being accepted by some authority to represent Earth. It shows the composition of the Earth: 30 percent land and 70 percent water (roughly) is heralded by the 10 colored semi-circles, which also emulate arches: how one aspect holds up others and, in part, eventually, the whole. The blue ones emulate the ocean waters; the green ones form a landmass which is crowned by a golden semi-circle; the 'city' - the ecumene of mankind upon Earth, their combined works and stewardship - and responsibility - over the rest due to their technological civilization. All upon the dark-grey void which Earth hurdles through.
The shape of the combined elements forms a mountain/hill/triangle/pyramid, jutting upwards, basically, allowing for another message of striving forth, of noting what has been done - from life emerging from the waters onto land onto technological civilization - and thus adding to the meaning of the whole flag.
Thus the flag combines both natural and artificial constants for the world. A flag that represents all parts of the Earth, with several messages - 'historical', 'natural', and 'environmental' strewn throughout.
Simple ratio of 2:3, colors: Dark Grey, Blue, Green, and Gold.