Comment Re:Wormholes + a flat universe (Score 1) 358
The further you zoom out, the flatter everything appears in relation to everything else (globally flat). If you zoom way in, you can find numerous examples of arrangements across all three dimensions (locally non-flat).
Even if gravity is unlimited and radiates volumetricly, as you zoom out, there is no matter/energy for the gravity along the Z-axis to exert itself upon. And remember, you can still compare infinite sequences. One can state gravity is much stronger along the X-axis and Y-axis than the Z-axis, even though all three are infinite. This is because the gravity-emanators, mass, are globally arranged flat. Therefore, in a twist of the meaning "flat", gravity, and the mass-having universe it lives in, is globally flat, too.