Interstellar Travel - Possibilities and Human Physiology

I have serious doubts in our ability to colonize other planets. To colonize a planet we would need a large portion of the conditions we have on earth. Attempts at long term stays in sealed biospheres here on earth have failed. We are a relatively fragile species with specific needs in temperature, atmosphere, nutrition, pressure, radiation, emotional support, and G force. Even if we found a planet with many of earth's conditions, an absence of an important nutrient could easily result in failure. If you take a look at our population growth curve and pollution production trends, you will see that they are not sustainable in the long term. I think we will run out of resources or poison ourselves with our own waste before we develop the technologies for getting to habitable planets.
I could see the possibility of creating a space ship that spins to create centripital force simulating gravity for long term travel but the vastness of space makes the colonization of a planet a formidable task.
The other reason for my doubt is the absence of aliens. Other parts of the universe are far older than we are and if life exists elsewhere then they theoretically should have advanced to have the technology for space travel and life detection systems but the reports of alien sightings on earth do not seem credible as yet. It may be that we are alone.
I see our best hope in space travel as learning how to warp space-time. The other possibility is traveling through other dimensions. According to the string theory, there are ten or eleven dimensions. We detect only three space and one space-time but it is possible that the others were shrivelled up during the big bang. If we could find the others, a small distance in another dimension could be a huge distance in ours and allow us to travel to other parts of the universe. This is bordering on fringe.

I agree. We would probably have to use centripital force to simulate gravity since artificial gravity doesn't seem to be anywhere near possible in the foreseeable future. The problem would be in the resources. I could see how a space station once built could be self sustaining but it would take an incredible amount of resources to build and people on earth are doing a good job of using up the resources we have. For a space station to build another space station would require a vast amount of raw materials which we would have to get from somewhere. If they aren't available from earth, the space station personel would have to find another moon, asteroid, planet, etc. with all the right resources and set up mining and processing facilities. It is possible but we would need some pretty incredible advances in technology to pull it off.

I have a high opinion of my species (I assume that it is the same as yours) but I think we are going to run out of time. We have to be able to create interstellar travel, make habitable biospheres, and find a planet that could support us soon (in the geological time line). Starting now and working backward it took about 40 years for the human population of the planet to double. Before that it took 60 years, then 150 years, then 700 years and then 1250 years. If this trend continues, the doubling time will become shorter and shorter and we are currently close to 7 billion people. I predict that in another one or two doubling times we will not be able to sustain the population with earth's resources. That would give us about 50 years to accomplish another planet's colonization. I know this seems pessimistic but I don't see major faults with this timeline.

I agree that robotics would be a much more practical in space travel. It would be much cheaper to put robots on the moon and they would be able to do practically the same tasks as humans in the current moon missions but it is not so glamorous and exciting. The politicians need the populations financial support so they go for humans because it appeals to our adventurous nature. I don't see how it could increase resources. Please explain.

Yes, that is the speculation on the life cycle of the sun but the question is, how long do we as humans have to develop technology for space travel. I propose that it is less than 100 years due to the increasing population, decreasing resources, and economics. By economics, I mean the amount of money that countries are going to have available for huge expenditures like space stations. According to Sir John Glubb Pasha's model of the rise and fall of world empires, the U.S.A. is in the final stage and will steadily or suddenly decline as a world economic power. There are as yet no other countries strong enough economically and politically to replace them so I think we're in for a period of tight fiscal policies. It may be decades before another country can come to the forefront of economic might.

Hey, Subbie. Kind of weird meeting you out here. I'd be happy to be proved wrong. Look at the human population growth curve on this page.
http://users.rcn.com/...anet/BiologyPages/P/Populations.html(Hope I did that link right) Can you see this being sustainable? Yes. I think it lends more credibility to the model because he couldn't look back at all of the U.S. history and create a model from it. One of the interesting parts is his take on heros. He says that heros are usually associated with the stage. ie. explorers are heros in the pioneer stage, business leaders are heros in the affluence stage, etc. During the last stage which is one of decline he says that people become disenfranchised and their heros become athletes, actors, and musicians.

No, absolutely not. I think that the human race will continue for many, many years into the future. The exponential population growth curve along with the depletion in resources would result in difficult fiscal times and a lack of supplies that would make huge endeavors like massive space stations and far reaching space exploration extremely difficult.

Resources would include minerals, metals, and fuel.