[ryugarden]

This is true, we can travel only up to 8.2 billion light years (radius of the affectable universe/2) which is the largest completely causally connected region, in the sense that every point can observe and reach every other. 8.2 billion light years is the furthest distance that we could reach and then return from at the speed of light. And it is much smaller than the radius of the observable universe (46.4 billion light years)