In his controversial book, the author explores a radical possibility that physicists usually do not consider, namely the reality of time. While in everyday life we perceive time as real and completely subordinate our actions to it, such a perspective on time is unsuitable for the purposes of physical investigation. Physicists, when examining and formulating the laws that shaped and continue to shape the nature of the world, see time as an illusion: in ordinary perception, everything changes with time, but physical laws are usually understood as immutable in time, universally and always valid. However, Smolin argues that everything could be quite different, that even physical laws can change over time; and he examines what consequences this would have for science and for the world as a whole.
