With the idea that our world is probably not so unique among the millions of star systems and billions of planets, in the Milky Way alone. The chances of there being other intelligent races is pretty good.
Also we tend to discover something mind-blowing every decade or so. Things we had no idea existed a generation ago (atoms, quarks, types of planets around other stars, DNA, etc..) are a reality today.
Having said that, I believe there are many alien civilizations in our neighborhood of the Milky Way and faster than light (FTL) travel is possible. We just aren’t there yet.
Many ask. “Why don’t the aliens visit us?” Well let’s be honest and put the ego aside. We really are not that special are we?? If an alien race has discovered how to travel between the stars in a time frame that is acceptable to them, then what are we to them? A pre-contact Amazonian tribe?
How many of us are rushing to go say hi to those that remain? Yes, we like to see the occasional article about them and maybe a National Geographic special or a Youtube video but really how often do we think of them? Please realize this is not to denigrate these tribes, just using as an example we might understand.
If there are millions of earth like planets in our galaxy, then aliens coming here for our resources is probably an idea that should only exist in Hollywood. Humans are the resource they want, you say? Okay why? We are rather frail, we can not exist easily in many other environments, we are rather annoying and hard to keep in line. Wouldn’t a prospective overlord race think that robots would be better choice of labor than these little meat bags?
They want to rule us you think? I would imagine before they “pushed the button” they would investigate us for a while. Especially since we do not have the technology to detect them. Once they watch us for a while, what do you think? Would any self-respecting conquering race try to bring a bunch of psychopathic, inventive short lived creatures into their empire?
With the ability to gain any resource anywhere else in the galaxy and us being primitives, what value would we serve? Also we tend to fight ourselves and not just for mating, we are really good at killing each other. Why bring such a crazy race into your empire with the chance they might infect others or God forbid, learn new technologies where they might challenge the established rule.
No, if anything it would be best to watch us. Like we do the Amazonian tribes with fly overs. Keep an eye on us. See if we kill off ourselves or actually learn how to work together and get into space. Then they can take us over or if not the conquering type, they might welcome us to the neighborhood.
“We should hear their signals.” One might say. Well think on it. We have only been broadcasting roughly 100 years. In that time most of our communications is now via the internet (land lines mostly), mobiles (short range) and satellite (directed communications). Most broadcast medias are being replaced. There is talk of quantum communications, where there is no signal path. With us doing this in 100 years and still have barely left our planet, what do you think a race that can go between stars is capable of?
Most likely to hear another civilization, we would have to catch them in the first 200 years of their space age. After that, then the chances for them to emit radio waves for us to pick up will drop off significantly.
What we might be able to watch their graviton emissions from spaceships flying near our solar system. We have recently figured out how to measure gravitons. Now it is just for the truly big objects in the Universe. In time we might refine that ability. If the aliens use big ships, then chances are they will cause a disturbance in the gravitational waves as they fly by, snapping their versions of pictures at the primitives.
Like the tribes people looking up at the sound of an airplane and wondering which Gods they might be and what would happen if they come to visit. We will hopefully one day track a graviton emission passing our solar system at speeds well above the normal stellar objects. We too will wonder what god-like beings are doing that and what does that forebode for us, if they decide to stop and say hi.