The problem with this long distance travelling is that we cant travel in the speed of light. But latest experiments implies the possibility of this feat. Even so there is an obstacle. According to Einstein’s Theory of Special Relativity, a mobile object experiences time changes relative to a stationary object. Even though this seems absurd, it is because we are moving at a very slow velocity compared to the speed of light. Scientists have proved this fact by sending high accuracy atomic clocks in high speed rockets. When they returned to earth they showed fractional changes. It means that if we travel at the speed of light, everyone except travellers will be in a different time dimension than that felt by the passengers. For example, for a journey which will take normally 25000 years to travel with respect to surroundings or observer, it will only take about 10 years to the traveller. this a paradox since if we travel at the speed of light, or nearer to it, the rest of the people will be aging exponentially than us resulting in a time traveling situation to future. We will simply want to avoid that .
Thus travelling at or beyond the speed of light is out of question, we need to think of a different type of approach. Say good bye to travelling and velocity.Take an example..
Consider a small marble ona paper sheet uniformly folded. For changing the position of that object from a point A to B, we can move that marble from A to C. This has been our approach all the time. But say, when the marble is between A and B, by fixing the marble and extending the part between A and the marble and folding the part between B and the marble , we can change the position of the marble. In otehr words, we are pushing the initial point faraway and dragging final point nearer to us. Thus there will be a change in position of the marble without moving. This may seem absurd to involve in practise..
But the Space Time Continuum theory which adds another dimension to the normal three dimensions points to this fact. The fourth Dimension is time. Thus according to this system, every point in the cordinate system is an event not a position.Space time continuum can be viewed as a plane simply (but a lot more complicated than that. See the figure above. One can see that the plane slopes at times where there is gravity.
Lets not deviate.. The main concept as explained above is to consider the space time as the piece of paper and the marble as space ship. The plan is to expand the space time continnum. It will be like Star wars. It requires the production of a warp bubble made of negative energy. Inside this bubble, spaceship lies will have no relation to the surroundings ad the space time continnuum around it will be manipulated just like the paper in the example. This is called Alcubierre warp drive and the spaceship will change the position at unimaginabe speeds.And it will not violate any laws since the object is not moving.
Although this seems absurd (It is absurd actually), Scientists are claiming this can be achieved although the facts lead us to unimaginable costs and impractical sizes. Energy requirements for some warp drives may be absurdly gigantic, e.g. the energy equivalent of -1067 grams might be required to transport a small spaceship across the Milky Way galaxy. This is orders of magnitude greater than the estimated mass of the universe. But eventhough this is a seemingly impossible fact, scientist sare saying this can be overcome by the use of tachyonic mater. An Alcubierre Drive is needed for building an Alcubierre Drive. Since none have been proven to exist already then the drive is impossible to construct. Eventhough this all offends the alcubierre warp., lets hope a technology like that will be developed soon and such a technology will help us explore the space further wide.