What makes computers so powerful is that they can process very quickly. This computing power is very useful in physics and science.

Traditionally there are theoretical physicists and experimental physicists. Theorists do paper and pencil calculations to derive formulae and make predictions from their formulae. Experimentalists can design experiments to test the predictions and the theories. Experimentalists may also discover unexplained phenomena in their experiments. Theorists then try to devise some theory to explain the phenomena. The problem is that formulae can not be compared directly with experiment results. It is usually difficult to get numerical results from an equation to compare with experiments. The formulae are often very complicated differential equations. Many are so complicated that they can't be solved by hand at all.

After the invention of computers, people found a new way to solve equations numerically using computers. Consequently, a new branch of physics emerged...