SO - - WE HAVE RECEIVED Radio signals from the Hollow Earth. What kind of signals ? It kind of makes sense, knowing the Earth is Hollow - - but what kind of signals. I am not sure Short Waves would go that far through "dirt", but if the message was attached to a Gravity Wave, than it would be possible. That is how most Alien technology communicate. A gravity wave travels at the speed of minimum 163 times the speed of light.