Could we actually fight a war against an alien race?

[Dodece]

I wonder if it has occurred to anyone responding to this thread that human beings are capable of interstellar flight themselves. It is simply a matter of priorities. There is no technological limit to doing so, and no future development in technology is required. In fact we have been quite capable of doing so for decades. The only leap necessary for any race to do this is the one it takes to reach orbit. Once in orbit you can build a massive beast of burden to keep a large crew alive long enough for free momentum to get them from star A to star B.

They are called generational ships, and that is the most likely encounter based upon what we know about physics. A ship that started its flight ten thousand or a hundred thousand years ago many light years away. Arrives at what their astronomers determined was a potential candidate for colonization. In such a scenario the aliens are royally fucked. They wouldn't expect to find a advanced technological species upon arrival. A species that would likely be on a even playing field, and one that had all the advantages in manpower, materiel, and position. The latter is kind of crucial it is a lot harder to sink and island then it is to sink a ship.

The environment we will be working it will be hospitable, and self regulating. No matter where a bomb drops we will still have, air, water, and food. The aliens in the ship will be in a hostile environment, and their ability to shrug off damage will be limited. Put too many holes in the ship, and they will suffocate, Destroy enough shielding, and the radiation will kill them. Destroy their food source, and they are put up against a clock.

You see the thing about these debates is they ignore something painfully obvious. The Earth isn't worth having for anyone other then us, and races at our own level. The Earth isn't particularly a good source of any raw material. Asteroids are a better source of heavy elements. Comets are a better source of volatiles. Lighter elements are much more available in nebulae. So we ain't got nothing of real value. There are literally Small asteroids that contain more precious metals then have even been mined by humanity in its entire history.

The Biomass of the planet isn't even all that attractive. The plant life is largely poisonous. Microbes are always fun to deal with. There is nothing the life hear produces that cannot be synthesized by unnatural means. Oh and then we have all the nasty critters that use venom, bite, and spray vile compounds.

No you actually got to be kind of desperate to want to steal the Earth. Only a generational ship fits that bill. They would arrive, and have no choice but to land. Any species able to bypass light limitations would have much better things to do. When you get to that point you have a species that could tailor make dead worlds to their liking. No dealing with a foreign biomass. Hell who needs a planet anymore. You can build large constructs that exceed any mere planet.

No the only real threat we would face is from a species at a comparable level of technology to our own. We are the only ones who would need to colonize a existing world, and are deeply dependent on possessing a world in order to sustain ourselves. I would actually feel sorry for any species that arrived at Earth after eons in deep space only to find a no vacancy sign. That would suck, and the worst part is that about a hundred years ago they would have got their first sign that somebody was at home. Far too late for them to change coarse, and no they would not likely have a massive arsenal on board. Did the Apollo capsules come armed, how about the Space Shuttle. They wouldn't have likely brought weapons of mass destruction, and it is actually counter indicated doing so. Why bring a weapon with you that one lunatic might find a way to set off.

We would win, but only due to the fact that are adversary would actually be weaker.