Mass

In this informative and readable account, the author traces the history of mass from the Greek atomists to quantum fields. He shows how modern developments have undermined comfortable preconceptions and given us a completely different perspective on the world. Most of what Baggott writes about has occurred in the last 100 years, and he writes compellingly about these developments with five-point summaries of the end of each chapter. A key insight is that the mass of an object should be understood as a behaviour rather than a property: 'something the object does rather than something it has.' Ultimately, he explains that mass is in fact a secondary quality: 'there is no such thing as mass, there is only the energy content of quantum fields.' In elaborating the features of the standard model, he nevertheless points out that it is full of explanatory holes and that scientists are forced to speculate. However, at the end of a century of extraordinary progress, we are humbler than our 19th-century forebears in admitting the extent of what we do not yet know about 'the reality of things-in-themselves.' It is possible, however, that this phrase may put us on the wrong track by implicitly denying a more fundamental role to consciousness in the overall scheme of things.