Why do we always think of space faring aliens as super advanced instead of medium advanced?
It's the other way round - aliens depicted in sci-fi movies are way too primitive to be believable.
Seriously, an alien specie has invented interstellar travel but is still trapped in fragile biological bodies? Pathetic. Digital minds are way sturdier, flexible and redundant.
They need to come to Earth and fight a war to destroy us? Weak sauce. An ultrarelativistic particle beam fired from light years away will do.
Big and clumsy vehicles that require drivers? Come on. Even humans have unmanned drones that can make murder distant and impersonal.
Biological weapons? Please. Why give humans a fighting chance? A swarm of nanomachines to sever essential nervous chords while we sleep will get the job done just fine. Or alternatively turn the planet into grey goo.
Looking for resources on Earth? Seriously? What, do alien spaceships run on oil?
Of course, movies and novels need a story arch and drama, and you can't get either if the human race just goes *squish* at first contact. And we shouldn't project our own motivations and morals onto beings that evolved in a completely different environment than us. What we can do, however, is make reasonable guesses about the technological capability of an interstellar civilization, because medium-advanced aliens sure as hell can't travel between stars.
*I don't know whether aliens would actually use these technologies I just described, but I would expect their capabilities to be at least this powerful since they're foreseeable even from our human standpoint. Neither am I making assumptions about alien motivations; just saying that GIVEN that aliens WANT to destroy us they could easily do so.
Basically, because they would NEED to be super advanced.
Let me just point out something: Space. Is. BIG.
It is estimated that the universe has a radius of around 46 billion light years. Inside of this universe, conservative estimates suggest that the number of galaxies exceeds one hundred billion, and that, in our galaxy alone, we have at least one hundred billion stars (although, it could be more than two hundred billion). That's a huge number of stars.
But remember, these stars are pretty far away. The nearest star to our Solar System, Proxima Centauri, is about 4.3 light years away. To put that into perspective, a light year is approximately 5.8 trillion miles. Compare that to the distance between the Earth and Mars, which, during a Mars-Earth Opposition (where Mars and Earth align), can vary between 40 million to 70 million miles. Our rockets, at best take six months to reach Mars. At the rate these rockets would go, it would take thousands of years to reach Alpha Centauri. So, our rockets are practically useless. We haven't even sent men to Mars yet, nor do we have colonies on the Moon. That shows you how primitive our space programs are.
A space-faring civilization, on the other hand, has figured out how to exceed those speeds. Likely, they would have had to develop nuclear fusion (or, at least, efficient nuclear reactors) for their spaceships. Not to mention that, if they were wanting to conquer a world, they'd have to also perfect cosmic power projection, i.e. projecting military force over many light years away.
The power required to travel, even at low-level relativistic velocities (like, at 10–20% the speed of light) requires technologies advanced enough that we'd need decades, if not centuries, to have a ship that can reach those velocities. Not to mention the ability to project military and civilian forces over those distances requires large ships. So, they'd need advanced technology for that. And if we're talking about warp drive and other modes of FTL travel, it's even more complicated.
Odds are, they would also have to have advancements in other areas, such as in artificial intelligence, biomechanics, etc.
So, the reason that we always assume that a space-faring civilization is super advanced is that is, practically, the only way it could even become one in the first place.
Why do we assume that they haven't contacted us?
Why do we assume that aliens are human sized? What if aliens are microscopic or galactic? What if aliens are sub-space dwellers? What if I have an alien ship inside me exploring my guts?
They may even have something like in Star Trek's Prime Directive that forbids them from contacting lower life forms. Yes, I'm saying we humans are a lower life form.
Why do we assume that we're even intelligent and smart? We haven't even journeyed through this entire planet yet! We still have wars going on. We can't agree on what government to use. There are people who believe in religions and people who don't.
What if these aliens are part of a universal version of the UN and they're seeing if Earth should be included by our actions? Maybe they're think, "we should come back in about another 1000 rotations. They're not even close to ready."
I would think that there are aliens out there at all different stages of development and I'd place us somewhere in the middle...possibly a little less. I also believe that some of the more advanced are in fact visiting us, and have been for thousands of years. There are cave markings and other art showing just that... UFOs and Extraterrestrials in Art History . I've been studying the alien phenomenon for about 18 years ..ever since I saw my first 5 UFO's, and what I've learned is that they ARE here, and have been for a long while. Check this out .... Steven Greer: Citizen Hearing On Disclosure 2013 HD and if you want to see a bit more ....
The conclusion comes from two observations:
- The universe has been habitable for much longer than we've been in it.
- Technological progress proceeds exponentially.
Because our time in the universe is such a small fraction of the time that its been habitable, it's probable that alien intelligences will tend to be older than us. If it took us 10,000 years to go from subsistence agriculture to the James Webb Space Telescope, how advanced will an alien intelligence be that's just 10,000 years older than us? What if they're a million years older? A hundred million?
The universe is big. Like, really big.
Generally in science fiction, the spacefaring aliens we see are capable of interstellar travel. This kind of technology has to be extremely advanced, because, as I said, the universe is big. A race with this technology could not be, as you say, "medium advanced", and as such, the aliens we typically see in Sci Fi are super advanced.