With our current understanding of physics, it doesn't seem possible but the key word is current. Scientists recently measured particles going faster than the speed of light. Granted it was not much faster and is still not verified, but if that's possible, it'd stand to reason that there could be other advancements that could do it. If you asked anyone a hundred years ago if they thought they could have real-time communication with someone half way around they world, they would think you were crazy.