I don't know that I have your answers, Divine_Key. I can make some speculations or if you wish I can hunt up an e-mail address where you can ask them. SETI is looking for life, more or less, as we know it. Therefore they look where they suspect it would be if it near like us and in the same technological area. If we were in the cave man days, we could not communicate. Places like the hydrogen band are the most noisy and therefore some of the worse places to look. When you get into the what if's, they go one for ever. What if they encrypt? Or if they hide their signals because they are paranoid? What if they use the next genereation of equipment that we don't have yet and can not intrupret what we see as a signal? You can do a search for the "wow signal" to see what it looks like. It was a signal that was observed, never repeated, but was recorded. No explainations to present have emerged to show what it was or what it might have been. Welcome to sciforums, Divine_Key.