Science is constantly changing and constantly rewriting itself. Theories of yesterday are changed today and will be changed again tomorrow. All this changing begs two questions; what is behind the changing and what is everything changing to? In physics, theories are developed and changed in order to make way for the new ideas and questions that are coming. Theories are made by reduction and holism and these to views have developed some of the most powerful theories in order to explain the world. Now with all of the theories in front, one last change is needed to make everything complete, a change to a unified theory, one theory that can explain everything. This theory would be the pinnacle of the science and man's achievements.
Reductionism is one of the two key contributors to the theories and advancement of the theories in physics. Reductionism is the principle that the parts that make something up can explain everything. "For the last 400 hundred years science has advanced by reductionism The idea that you could understand the world, all of nature, by examining smaller and smaller pieces of it," (Dictionary.com). This view of physics implies that since the parts that make it up can explain everything, that there is a hierarchy classification. "They suggest the following levels: elementary particles, atoms, molecules, living cells, multicellular organisms, and social groups," (Newton-Smith 402). So by looking at this hierarchy, to be able to understand anything completely as possible, one would have to be able to understand elementary particles. This is why reductionism has been so key in subatomic physics. On this basis, reductionism has been very successful with the development of the Standard Model and grand unified theories. The Standard Model and grand unified theories are two theories that combine the three nongravitational forces. With this previous success, the reductionists believe that reductionism is the key to finding a unified theory.