Why we haven't found ET

The Search for Extra-Terrestrial Intelligence (SETI) has been studying the heavens for radio signals from other civilizations in our galaxy for forty-six years. But even in the days when the search was conducted with a big budget and equally big radio telescopes (currently it's crunching its data largely through a special screen saver which allows laymen like us to let the program use the resourcesour PC's during downtime), not much of the galaxy has actually been searched.

Besides, there might well be reasons why we're not getting signals from ET even if he's out there.

Absence of evidence, as someone once said, isn't evidence of absence.