One of the things about science fiction that has been the most remarkably evident is the evolution of scientific work over time. Looking back at early examples of sci-fi such as Star Trek and H.G. Wells’ The Time Machine there is a reoccurring idea of an infinite outside universe or a galaxy unknown. It is unlikely that characters of science fiction live in present times. Instead, they reside in a futuristic atmosphere or a historical past that contradicts historical facts. There is a large association with space. As science fiction has evolved over time, it has become redefined to include unnatural villainous creatures such as aliens as seen in Alien and Signs. More presently, we see humans in typical everyday setting in the possession of supernatural subhuman powers. Some examples of these films include The Matrix and Avatar.
Elements of science fiction have been implemented into many genres of film over the years which has proven to be very complimentary. For example we see the notion of “time travel” in many comedies such as “Bill and Teds Excellent Adventure” and “Back to the Future”. Aliens and supernatural creatures have been implemented into several films such as signs and Alien vs. Predator. There are of course many other films of various genres that are accredited for their implementations of science fiction elements. These elements have proven to be very successful in creating cross-genre works.