I finally found 2 extremely relevant articles after digging through my Stumble history.

The first one, http://www.thesun.co.uk/sol/homepage...to-aliens.html, is about how satellites are cutting down/eliminating our radio waves that we send into space.
"Dr Frank Drake said transmission of signals into space was being cut by the digital revolution.

As a result, any little green men on other planets would not be able to detect them.

Dr Drake said Earth was surrounded by a 50 light year-wide "shell" of radiation from analogue TV, radio and radar transmissions. The signals had spread far enough to reach nearby star systems but are vanishing.

He explained that while old-style TV transmissions could generate one million watts, digital transmissions are much weaker."

This means, to me, that other advanced civilizations (who would likely use satellites in one form or another) may have reached this stage long ago. This would make them very hard to detect for us.

The second article is about the age of Earth compared to other planets, especially ones that would likely harbor life. "...that the median age of terrestrial planets in the Milky Way is about 1.8 gigayears greater than the age of the Earth and the Solar System, which means that the median age of technological civilizations should be greater than the age of human civilization by the same amount." Basically this article is about the technology gap this could have created and what that would mean. http://www.dailygalaxy.com/my_weblog...y-classic.html

Just thought I'd throw those out there. They seem like decent explanations for the silence.