ABSTRACT
This chapter encounters a number of ways in which contemporary physics threatens common-sense views of space and time. The theoretical programme aimed at integrating GTR and quantum theory that more than merits a mention: string theory. The physicists explored the idea that the problems with the original version of KaluzaKlein theory could be solved by positing still more spatial dimensions. The electroweak theory and quantum chromo dynamics were combined to provide a complete account of three of the four known interactions, and the standard model was born. The starting point of the cyclic model is a hypothesis as to the structure of the cosmos. Hence experiments at detecting cosmic gravitational waves, have an added interest: as well as confirming a prediction of Einstein's GTR, they may allow us to rule out at least one of these competing cosmological models. The string and loop theories have fascinating implications, likewise the canonical approach and some of the other more radical approaches being considered.
