pass by. These searches have discovered countless planets. The next challenge is to find one that is neither too hot nor too cold, where there is water necessary for life forms to develop. Then the problem is how we would get there. As these stars and planets are many light years away, it would take hundreds or thousands of years to reach them. Creating a spaceship that could travel at the speed of light would be one option, but in the film, Earth does not have that much time and a quicker route must be found. Thus the problem to be overcome is time itself. Again, real science provided an answer, which was then brought to the screen in the film. As Einstein famously described, time and space are not two separate things, but exist like a fabric that our universe is made of, called "space-time". Objects such as planets and stars bend this fabric, creating the force we know as gravity. When this force is very large, space-time is bent a great deal, making it possible for a short cut, known as a "wormhole", to appear. This would allow one to pass from one point in the universe to another without having to cross the space in between, therefore making the journey much quicker. Wormholes are often used in sci-fi stories, appearing as simple holes to pass through, but what would one actually look like? Science tells us it would actually look like a sphere, through which we could see through to the other side, and so this is how it appears in the film. In the film, such a "wormhole" mysteriously appears near Saturn. Several astronauts have already been through, with some reporting back on promising planets they have found. The team travels through it to another galaxy in the hope of finding a new home. However, as hours pass on these distant planets, many years pass on Earth. This is also a realistic depiction of what such interstellar travel would be like, as described by Einstein's theory of relativity. Time moves differently depending on where you are and whether you are still or moving. Of course, sometimes real science has to be ignored to make sure that a film, which is only a few hours long, is entertaining and that viewers understand what they see. We cannot know exactly what interstellar travel looks like, but science can give us a good idea. Often, there is a fine line between science fiction and fact, which is always changing as science and technology progress. Things that were only being dreamed of years ago are now part of our everyday lives, such as the Internet, mobile phones, and soon even space travel itself. This is what continues to make sci-fi so exciting and popular, inspiring generation after generation to imagine our future existence.