The stars above us are a beauty that men have fashioned whole mythologies around. They are truly a sight to behold, and now that we have extended our reach to the moon, the natural progression is that we might want to travel to the stars. Such travel is a basic part of countless science fiction stories and films, and many might come away with the impression that interstellar travel is an easy task, perhaps just around the corner for the wit of man. Sadly, there are a few serious problems which must be addressed first.
Faster than Light
Many stories include zany explanations of how faster-than-light travel is possible. The reality is that physics prevents this. There are no cheats. Even close-to-light travel runs into all sorts of interesting relativistic problems involving mass and energy. Our only possibility is to use wormhole portals. Such a wormhole would have to be carefully controlled, which is beyond our present capabilities, and we would have to somehow manage to create a twin wormhole far off at our desired destination, which might require someone else at the other end. Needing someone else to be there beforehand is not feasible for the first interstellar flight. Worse, the physical effects of traveling through a permanent or semi-permanent wormhole would warp and destroy any matter. You would arrive at your destination as a plasma.