The red dots (of course) show the distribution of the worlds 2200 TV transmission stations.
Only a small percentage of this broadcast TV is intercepted by an antenna on the earth, most of it escapes into space.
Similarly, only a small percentage of Military Radar transmissions is bounced back to a receiver --> most of that energy also escapes
Hence, intelligent life on the earth is announcing its presence directly via Television and Military Radar!
Over the last 40 years or so the radio power of the earth has been steadily growing
Because of the non-uniform distribution of TV transmission towers (red dots in the masthead figure), the earth has an interesting spectral signature when observed from some nearby star, in this case Barnard's star located at a distance of 13 Light Years. This spectral signature potentially gives information about:
Our non-equilibrium growth is clearly manifested by our increasing radio leakage to the cosmos.
Next Page (the end of civilization)