The problem with aliens

I had an interesting conversation on Fark today. This sort of thing comes up every now and then, and I love the discussions that ensue. I'd like to say that I love science fiction in general, but really, I love the idea of science fiction more than I love the genre itself.

It comes down to this: if you want to make a traditional spaceships and lasers science fiction story interesting, you have to make it into a fantasy. Since I was talking about aliens today, we'll start there.

The problem with aliens, whether in a science fiction story or UFO fantasies or doomsday prediction is simple:

Any civilization that has achieved interstellar travel has no use or need for Earth or anything on it.

Interstellar travel by biological organisms requires a container that can survive years in deep space without any energy or material input. Because of the energy requirements for moving mass, it's exceptionally unlikely this closed system is stocked with enough supplies to sustain the organisms for the duration of their journey. After all, with enough energy and efficient recycling, you can create a self-sustaining closed system using far less mass.

In fact, since aliens have to obey the same laws of physics we do, any craft capable of interstellar travel would have fuel make up 95%+ of its mass. The remaining mass has to include all of the spaces, systems, and supplies that biological organisms need to survive a few decades in transit. And therin lies the problem.

Because if a civilization can create an interstellar spaceship, it can also create self-sustaining artificial habitats in a fraction of the time for a fraction of the cost.

An artificial habitat in close orbit around the civilization's home star can fabricate anything it could ever need using the star's incredible energy output and by harvesting mass ejected by stellar eruptions and stellar wind. In fact, the only difference between an artificial habitat and an interstellar spacecraft are engines and fuel. The habitat needs neither. Instead, the habitat can have more useful, practical things, like an expanded self-sustaining ecosystem to improve the quality of life of its inhabitants, or solar collectors so anything the inhabitants want or need can be manufactured in short order, or even simply more internal volume so the inhabitants don't have to spend decades hot bunking with each other.

In fact, if a civilization can create an interstellar spacecraft, there is no necessary reason it to leave the orbit of own star until their total energy consumption matches their star's output, or the star itself goes extinct. And when and if either of those things happen, their destination would be the nearest star. It takes mindboggling amounts of energy and time to travel from star to star. The fastest proposed propulsion humans have come up with would take more than 40,000 years to reach the nearest exoplanet. The same method could reach Proxima Centauri in a decade or so (assuming it actually works, and assuming it ever gets built).

And when your civilization can create anything it could ever need on an artificial habitat in close stellar orbit, why would you have any use for the rocky planets around an adopted star? Why would you travel to a star with rocky planets in orbit when there are hundreds others that are closer and give you everything you need? That's not to say that aliens would never leave their home star, just that the only reasons for doing so are curiosity and leisure.

Therefore, there is no necessary reason for aliens with access to interstellar travel to come into conflict with another civilization.

There is no competition for stars, which are the only physical resource worth mentioning. Information, the only other resource that matters, can be gathered in countless ways that are faster, cheaper, safer, and more effective than sending biological explorers into the void.

Now, yes, it's possible that an interstellar civilization would be interested in establishing trade with humanity, although anything traded would have to exceed the cost of shipping, which is unbelievably high. It's also possible some aliens would want to visit or study humans in person, even though sending a probe would be exponentially more efficient.

But it's not necessary. An interstellar civilization needs nothing from planet-bound civilizations. It cannot be threatened by them, it cannot be infringed upon by them, and it cannot be bothered with them.

Interstellar civilizations have every reason to ignore planet-bound civilizations, and no reasons to be hostile with other interstellar civilizations.

If interstellar civilizations ever come in contact with each other, it will likely be via radio, so they can trade ideas and information without ever leaving the bounty of their home and/or local star(s). Sure beats farting around in the interstellar dark for a few decades so you can look at some apes that your probes can get better pictures of anyway.