kelvinzero":3nen9dsn said:
We already build cities that hold millions of people. We could build much bigger but ultimately we are limited by the amount of farmable area on this planet, which recieves only the tiniest fraction of the suns power.
Okay, now this is getting ridiculous. HOW are you going to keep an object with a diameter bigger than Earth from collapsing in on itself? At first I thought you were talking about O'neill cylinders, which are at least feasible. But you're talking about literally planet sized stations here that can hold billions of people.
I don't suppose you want to give us any dimensions on this thing do you? Or could it be that you have no idea what you are talking about?
The only thing you need in order to build a deathstar-sized colony is one single tiny self sufficient colony capable of building another colony
Not only that, but trilliosn upon trillions of dollars, and I'd say billions of tons of metal to put this thing together. WHERE do you suppose we can get such resources? And even if you do must the resources, there's no guarantee that this structure will be completely safe. Like I said earlier, it could collapse in on itself. Any station that big will need a massive supercomputer to keep all its systems running correctly- probably billions of countless subsystems scattered all over. And if any of the critical ones fail, it could mean death for the inhabitants.
You are talking about ways to do this, and maybe someday in the future we can build such massive objects like Halo rings and Rama cylinders. But you have yet to mention how any of this is safer, cheaper, and easier than travelling to an Earth like planet or even terraforming.
You mentioned something about viruses and predatory wildlife. But like I said earlier, these lifeforms would not bother with us because we do not fall into their natural foodweb which has been undisturbed for millions of years. Any animals would run away from us because of their natural instincts, and we do not know what types of viruses would be there- I doubt they would try to attack humans as there are many other animals for them to rely on.
And finally, no space habitat with an Earth-like environment will be completely free from viruses, disease, and predators. If you want your station to be self sustaining and Earth-like, then it will need those to keep from falling apart. If you have one species, you have thousands.
Then exponential growth takes off. All you need to master is the sorts of skills we have already mastered, eg manufacture, horticulture etc, but adapted for space. It will be by no means easy, but our current physics strongly implies that FTL is impossible. There is not much less cost effective than impossible.
Futhermore, even if we do get FTL, we will probably still have to develop all the same skills as we would for that tiny first colony in order to survive the trip, unless of course our FTL is so good that we can reach other habitable worlds while holding our breath.
You do not need to travel faster than light or even at light speed to get to other planets. The first expeditions will take many years to get there, and will probably not be coming back home, but I think that is something that people will be willing to accept. You'll find that getting a ship to another star system will be much easier politically and economically than building this gigantic station that holds billions of people that you're talking about.
Now look here, kelvin. I've asked you some questions in this post and since you are making such bold claims on an engineering board, I have a right to have them answered. So please do not ignore my post like you did my previous.