The idea of a particle moving and being affected by external forces is followed by the idea of the field. Later on, we encounter the concept of quanta. This is certainly a simplistic way to put it, but it suffices to demonstrate that physics is an evolving system.
If we look at the history of physics for the last 200 years, we see how the focus has been on unification of all the forces. In thermodynamics or electromagnetism we see how one force or type of energy is never created or destroyed, but only transformed. Einstein’s dream was to find the “Theory of Everything”, not far from today’s main goal in the 21st century. There have been two major theories that defy unification: Relativity and Quantum Mechanics. One deals with the very large, the other with the very small. But they both have something in common, the belief in symmetry. The general theory of relativity, quantum electrodynamics, electroweak theory, and even string theory, they all follow the main principle that there is symmetry in the world. They are all intimately related to mathematics. This may seem an obvious observation, but let me continue with the next step in the development of physics. After symmetry we find that the anthropic principle has been gaining acceptance. This principle states that a human understanding of the universe is not an accident. The universe knew that we were coming as I read once in an article. I believe that the gamma ray bursts which have an incredible power to destroy life as we know it don’t occur in our vicinity for a reason. There is a delicate balance between the miracle of life and the destructive power of a black hole. Physics has no alternative but to accept the anthropic principle as a law of nature. The evidence will continue to point to the fact that this universe is unique in terms of preserving life. A multiverse may be seen as an alternate explanation for why are there humans pondering about the origins of the cosmos, but it requires much more faith to be certain of infinite universes than to see this one as an universe tied to human understanding. All we need to remember is Occam’s razor in order to accept our one and only universe as the economical way to the truth.