English Language · English

Rearrange the jumbled sentences P, Q, R, and S between the fixed sentences S1 and S6 to form a coherent paragraph: S1. In order to talk about the nature of the universe and to discuss questions such as whether it has a beginning or an end, you have to be clear about what a scientific theory is. P. It must accurately describe a large class of observations on the basis of a model that consists of only a few arbitrary elements, and secondly, it must make definite predictions about the results of future observations. Q. It exists only in our minds and does not have any other reality (whatever that might mean). R. I shall take the simple-minded view that a theory is just a model of the universe, or a restricted part of it, and a set of rules that relate quantities in the model to observations that we make. S. A theory is a good theory if it satisfies two requirements. S6. For example, Aristotle's theory that everything was made out of four elements - earth, air, fire and water, was simple enough to qualify, but it did not make any definite predictions.