There are two main problems with galactic or inter-galactic communication: the enormous distances involved, and, the limits on the speed of light. Current theory, as well as numerous experiments, show that nothing travels faster than the speed of light. At that speed it would take 50 thousand years to send a message to the center of our galaxy, another 50 thousand to receive a reply. Rather impractical.
LeeH
(published on 06/04/2012)