This is a very good point. And to keep things in perspective, even though we have been transmitting in RF for 100 years or so, that mishmash of EM waves might not even be detectable much beyond our sun's near neighborhood. Also, we have not developed a sufficiently advanced technology to enable us to put humans in interplanetary space and safely shield them from the Sun's periodic tantrums. Until there are some real breakthroughs in propulsion, shielding, etc, we're pretty much stuck to this rock. Unfortunately, the Bush administration cut funding for NASA's breakthrough propulsion project even before Bush started crowing about sending men to Mars. I guess there are no physicists advising him or his handlers.Gold Barz said:What if the alien civilizations are just spread too much apart, even if there were 50-100 in the galaxy, they still could be spread so far apart that they havent made contact yet.