Jon Trevelyan (UK)
For anyone like me who finds the immensity of geological time (‘deep time’) both fascinating and fundamentally difficult – both emotionally and intellectually – this is a great book.
Paul Lyle has written it for environmentalists and policy makers to help them explain their concerns and decisions more clearly in the context of geological time, but these are not the only people who should read it. It covers (among other things) the history of man’s efforts to quantify the earth’s age (both relatively and absolutely), from the Ancient Greeks and biblical scholars, through the renaissance to nineteenth and twentieth century efforts to reach an absolute figure of about 4.54 billion years. It also covers the grand themes of geology, including the unifying theory of plate tectonics, and shows how an understanding of time is fundamental to geologists. Therefore, anyone with an intellectual interest in geology and why their science is quite different from the others should read the book.
As the author explains, fundamental to the concept of geological time are the concepts of the ‘Time’s Arrow’ and ‘Time Cycle’. The first refers to non-repeatable aspects of the flow of time (eg the extinction of species, and the creation of banded iron and an oxygen rich atmosphere); while the second refers to series of repeated processes (eg rock and water cycles, and the cycles of the moon and sun). Both concepts are essential to explain geological processes and both present problems for lay-people to understand.
The author clearly hopes that greater understanding of ‘deep time’ will lead to more awareness of the Earth’s vulnerability, as its resources are depleted by consumers and its climates are affected by global warming. We must realise that economic and political decision-making relies on this understanding. For example, the geology involved in creating crude oil (time’s cycle) takes so long that, for human beings, once our supplies have gone, they have gone forever (time’s arrow).
I can recommend this book on a number of levels and thoroughly enjoyed it. The author, Paul Lyle was a lecturer in geology at the University of Ulster, but has now retired to write about geological issues.
The Abyss of Time: A study in geological time and Earth history by Paul Lyle, Dunedin Academic Press Ltd, Edinburgh (2016). 204 pp., hardback, ISBN: 9781780460390