Al-Khalili's new book offers a comprehensive tour of time's mysteries

A review of Jim Al-Khalili's 'On Time' praises its thorough examination of both the experienced and physical aspects of time. The book disentangles contradictory views from general relativity and thermodynamics, asking how they reconcile. It is recommended for readers seeking a deep understanding of the subject, though it is not a light read.

The book organizes its inquiry around two distinct categories: manifest time, which concerns human perception of flow and the boundary between past and future, and physical time, which examines how different branches of physics define time's nature. Al-Khalili confronts the apparent contradictions between general relativity's dimensional view and thermodynamics' directional arrow, asking whether these frameworks can be reconciled with each other or with lived experience.

The reviewer notes that Al-Khalili prioritizes rigorous explanation over narrative flair, making the book substantial rather than breezy. At roughly 350 pages, it covers a century of physics insights while also introducing some novel arguments, such as the claim that perceiving constancy itself requires a background sense of time passing. The reviewer suggests the book could benefit from tighter editing but praises its clarity throughout.