I missed you there, could you explain me a bit what you mean with the assertion that gravity is not an independent force? Let's recap a bit, gravity sort off accounts for the effect that a massive object has into it's surrounding space, is it not? Then, gravity expresses itself as how much can a certain mass bend the space in it's vicinity... but then, the mass of an object has to increase the fastest it moves, then as an object moves faster it also bends more the space surrounding him?