Let's say the Hubble constant is constant in the time interval we consider. So subjective "horizon" for any object has the same radius R. Let's say Bob and Charlie are just within the horizon of ...
Distant galaxies are said to be moving away from the Milky Way (and us) at speeds approaching the speed of light. Since Special Relativity tells us that any object moving away from us at a velocity of ...
Can causally disconnected regions join up again? For example the universe is expanding faster than light creating cosmological horizon, but what if something causes the expansion to slow down and ...