Hence, Einstein’s is a more general theory of motion. In contrast, the special theory of relativity developed by Albert Einstein (1879–1955) in the early 1900s gives the same results as Newton’s laws at low speeds but also correctly describes motion at speeds approaching the speed of light.
For example, the laws of motion discovered by Isaac Newton (1642–1727) in the 17th century accurately describe the motion of bodies at normal speeds but do not apply to objects moving at speeds comparable with the speed of light. Many times a theory is satisfactory only under limited conditions a more general theory might be satisfactory without such limitations. When a discrepancy between theory and experiment arises, new theories must be formulated to remove the discrepancy.
The fundamental laws used in developing theories are expressed in the language of mathematics, the tool that provides a bridge between theory and experiment.
The main objective of physics is to find the limited number of fundamental laws that govern natural phenomena and to use them to develop theories that can predict the results of future experiments. Like all other sciences, physics is based on experimental observations and quantitative measurements.
