Ok, so SETI (the Search for Extra-Terrestrial Intelligence) has been at it for thirty years now without so much of a whisper of a signal from an alien race. So where are they? Consider, life has been on Earth for nearly 4 billion years, of which intelligent life has been around for less than half a million years. A tiny fraction of the history of life on Earth. So, life may teem throughout the universe, but intelligent life may be incredibly rare. We really may be alone out here. What do you think?