when i'm playing a web based game and flashback of an anime that i've watched before not long ago.

but then, something came in my mind, combine with the other information that i've get from other sources, including TV, books and other...

here is some problem.
1. human health problem, we cant live in space for a long time without the presence of gravity, our muscle will start to swell, until now, astronauts only can stay in ISS for half a year and they have to went back to earth, they have to do exercise regularly while in space to keep their muscle working and prevent swelling, this is what i heard from discovery channel some time ago

2. so we might need the presence of gravity in order to survive, so how do we get gravity in a colony ship? artificial gravity?

3. plants and organism need sunlight, when we were in deep space, how do we get sunlight?

4. oxygen, water, temperature, and food, without sunlight there will be no plants, even if there is, the plant will withered or very weak due to lack of sunlights, the water will surely run out no matter how we save it and recycled it.

5. political, racism, and religious issues, i doubt we will have a peaceful life in the colony ship, unless every human beings has the same mindset.

6. death rate, birth rate and education, how can we control the death rate and birth rate? and every adults and children need education, we need a totally new and unify education, but how can we unite people with different believe and mindset?

the fastest way to travel from A to B in space is by wormhole, with wormhole, you can travel from earth to the other planet far way in just a very short time without reaching the speed of light.

the another method is by our conventional propulsion drive, or maybe some more advance propulsion drive like the impulse drive in star trek?

furthermore, i dont think we are able to travel faster than light, imagine you are cruising at a speed faster than light where you overtake the speed of light, no light can reach you, what can you see?

make sense?

I recently found myself reading the classic novel Rendezvous With Rama by Arthur C. Clarke, and I was struck by how absurd and improbable its vision of the 22nd century looks from a transhumanist perspective. The interplanetary civilization envisioned in the book, like so many futures in classic science fiction, essentially takes 20th century human beings and projects them forward a century or two without human modification — no advanced AI’s, no genetic engineering, no cybernetic enhancements. This results in the kind of "monkeys in space" fantasy that has plagued the popular consciousness, from Buck Rogers to Star Trek. With all due respect to Mr. Clarke, whom I revere as one of the 20th century’s great scientific visionaries, the future almost certainly won’t look anything like the "United Planets" of Rendezvous With Rama.

Our current biological substrates are products of millions of years of evolution on only one planet: Earth. To think that this is the biological form that will colonize the solar system and beyond is short sighted and naïve. Almost by definition, human beings aren’t designed for space travel or life on other planets. The costs and risks of attempting to do so are not only excessive but unnecessary. Without some overwhelming motivation (imminent extinction, discovery of extraterrestrial life, vast wealth potential, etc.), it is difficult to imagine human primates in their current form colonizing other planets in a serious way.

When it comes to interstellar exploration, the situation is even bleaker for homo sapiens. The energy requirements for getting any spacecraft to the nearest stars are enormous, particularly if the craft is constrained by the needs of fragile human passengers. Barring revolutionary breakthroughs in physics, we’re looking at either multi-millenial missions or energy requirements in excess of total current global energy output. Neither option seems very feasible for obvious biological, economic and philosophical reasons.

Given these limitations, I would suggest that the best hope for making the physical exploration and colonization of space a reality (while awaiting breakthroughs in physics) is to focus our collective resources on modifying human beings themselves, and on abstracting and increasing our intelligence into more flexible forms. My guess is that the first earthlings to visit the outer solar system, and certainly the nearby stars, will not be humans at all but artificially intelligent probes capable of totally autonomous, adaptive behavior.

Speculating further into the future, even if the energy can be found and suitable propulsion systems designed to send spacecraft to the stars in a reasonable period of time, it’s not clear that they would be necessary for long. Since the most efficient means of information transfer on astronomical scales is electromagnetic energy travelling at the speed of light, it’s conceivable that space travel will be replaced by the transmission of consciousness itself as pure information. If intelligence is ultimately reducible to patterns of information, as most AI theorists believe, then it isn’t difficult to envision a network of "consciousness transceivers" being established by advanced probes across interstellar space. These transceivers would "download" minds directly into some kind of robotic bodies established at various locations of interest, allowing light speed "teleportation" of human minds across the galaxy. Obviously this is all highly speculative, but to my way of thinking it is much more believable than the thought of glorified chimpanzees rocketing across the galaxy in giant tin cans.
The Earth is round and is not  the center of the universe, just get over it