No Advanced Aliens?

No Advanced Aliens?

 

An article discussing super advanced aliens suggests that we should see evidence of their intergalactic activity, but we don’t, so perhaps none are close by. It is my opinion that given the scale of the universe, there should be a number of billion-year-old civilizations and probably one or more in our own galaxy. So why don’t we see alien Dyson spheres? I think the assumption that an alien civilization would grow to utilize all the power of a star our galaxy to be a mistaken assumption. At a certain point the goal of making as many of us aliens as possible seems ridiculous. Even here and now the population of Earth has been slowing its growth rate. Further, I suspect a super-advanced civilization would not want to interfere with developing civilizations by advertising their existence. With hundreds of millions of years to develop their technology, could an alien civilization hide their existence from our primitive tools?