Given the extreme age of the universe, and its vast number of stars, if planets like Earth are at all typical, then there should be many advanced extraterrestrial civilizations out there, and at least a few in our own Milky Way. Another closely related question is the Great Silence, which poses the ... - Nik

It's always funny to me when scifi movies and novels depict aliens as "thousands of years ahead of us in technology", or an interstellar empire that spans hundreds (or thousands) of star systems and they just happened to do it for example 10,000 years ago! Or the long-dead "master civilization" that's been extinct for... gasp: 100,000 years!!! Ok, I get the idea that it's for dramatic intents it's just never been logical. That's why I like Stephen Baxter's Xeelee Sequence novels... :D - Adrian

True. In every movie and book aliens are always more advanced in technology. This is actually the first article i read that explains why. And it makes sense ;) I always wonder why we keep searching for life as we know it. Cause what are the chances statistically that extraterrestrial life develops in form and shapes and intelligence as we know here on earth.... - Nik

Well, we have a sample of 1 to conjecture on. The thing is... physics, chemistry and [conjecturally] biology are probably fairly consistent at least in our galaxy, so who knows. There are so many factors to consider, but there are also a LOT of planetary systems out there so the odds are that there are "aliens" right now sitting on a planet wondering the same thing. It's just numbers. Question is how many pockets are out there RIGHT NOW and how far. - Adrian

We will eventually discover them (or they us), if they exist in our time. I don't think we should only be looking for something we already know. I mean why just look for planets with water and oxygen. It is so restrictive. - Nik

Because we know that recipe created life at least once, so statistically we can't be *that* unique. Also we are experienced in spotting tell-tales and traces, but with other chemistries we'd be hypothesizing, unless we can actually create the chemistry in a lab here on Earth (we may have... sorry, I'm not an expert). - Adrian