as i understand it a civilization as it continues to advance and reaches a certain point it is no longer broadcasting into open space as we have been doing since the s and instead reaches a point where all telecommunications are directed from space bound craft back to earth think about our cable and satellite tv and radio overtaking conventional broadcast tv and radio a dyson sphere is the ultimate form of this concept so basically it is important for our planet to intentionally broadcast these types of scientific messages as our unintentional broadcasts become less prevalent an advanced civilization out there should be theoretically as quiet as we were in the ' s and ' s there's a small window of opportunity to get some thing from them and they could have the same philosophy as wnt and stephen hawking warn us about be quiet and don't contact other peoples it is possible by making the first contact being of a scientific encyclopedic message we might be the beginning of trust but of course it is possible history will say earthlings are the ones everyone else in the galaxy should have been worried about i suppose earthling is correct but someone please let me know