It amuses me when scientists say aliens need the same living conditions as we do. Every living thing on this planet has evolved to suit the environment so who is to say that other beings couldn't evolve in totally different living conditions. Like inhale argon exhale helium etc.
As far as aliens dominating us for being inferior beings I am not convinced. It is true that we used to do this thousands of years ago but as time has progressed we have discovered many ways of settling disputes without war, although not always. The more advanced we become the more diplomat and civilized in my opinion, I'm sure that aliens with technology to travel billions of miles would have to be far more civilized than us and probably have very little material interest.
Well, because, it is impossible. Energy needs to be produced and used by any life form, anything capable of movement (to define "life" as simply as possible). That means that any energy producing method they use still has to follow the laws of physics. As any chemist will tell you, since inert gases can't react, and the chemical potential of helium is not less than that or argon, it will never happen. Life would have to be carbon-based, for one thing, since carbon is the only element that can concatenate to produce any of the more complex molecules needed for locomotion. Other elements have a very limited number of possible combinations, and just not enough to make for a "system" that could process energy. Energy is the great universal that knows no exceptions.
Still, within those parameters, we already have a lot of possibilities. Thare are even organisms on Earth that "breathe" poisonous hydrogen sulfide and produce sulfur as a byproduct. That is where all the sulfur deposits came from. So, oxygen is not one thing that is absolutely needed in an atmosphere. And there are certainly many more possibilities.
It is likely that IF there is other life, it may be completely beyond anything we are even capable of imagining. I'm amused, for instance, that so many people think that aliens even would have a face. Why? Because there are faces here?
The idea that we are all in a simulation is gaining traction. In early 2013, satellite data that will help in answering that question will be available. Whether we have collided in the past with another universe is an active area of research and one that is being checked as we speak.
