after rethinking my answer, i further propose a new problem...B is s stationary object....A moves away at the speed of light, C moves away in the opposite direction at the speed of light....now what is the relationship between objects.
if fact, if the "big Bang" theory is correct....there is matter traveling in opposite directions.....therefore, if you are going 1/2 the speed of light north, and I am going 1/2 the speed of light south....we could never see each other. ever
And yet people are still looking for “dark matter”. When all the matter in the universe is visible, the end will be nigh.
The other question is how fast are we going now?
velocity of the Earth around the Sun plus the Sun around the center of the Milky Way = 156 miles per second or 561,600 MPH.
But I cannot find values for our velocity in our galactic cluster or of our cluster’s velocity in the universe at large. Nor can I find a value for our velocity relative to the mono block.
What if we are already going faster than c?
Actually that was how I (mis)read your first question...