Modern physics is now firmly entrenched in popular culture. Even though this may not be a new phenomenon, physics has recently gained a mass audience following cameo appearances in TV shows, films and – in some intriguing cases – as a central player in fiction. Jeanette Winterson, in her novel Gut Symmetries, puts forward the idea that “what physicists identify as our wavefunction may be what has traditionally been called the soul”. Martin Amis, meanwhile, has written a whole novel – Time’s Arrow – in which time runs backwards. Attempts like these to incorporate concepts such as relativity or uncertainty into non-scientific appraisals of reality abound.

John Charap’s new book on the physics of the 20th century attempts, among other things, to counter this “pseudoscientific prattle, New Age nonsense and millennial madness”. Charap – a theoretical physicist at Queen Mary, London – sets out to provide a text that “for a modest effort of attention” will supply us with the “large rewards” of understanding a host of modern ideas.

The scope of this book is certainly ambitious. Charap attempts to cover all the crucial developments of modern physics in the 20th century. He begins by summarizing Joseph Larmor’s lecture at the 1900 meeting of the British Association for the Advancement of Science, in which the speaker assessed the successes and unsolved problems in electricity and magnetism.

Charap then takes us through the discoveries that followed in the 20th century. These included the evidence that we live in an expanding – and possibly accelerating – universe, as well as the discovery of a plethora of unexpected astrophysical objects. Such objects are not, however, unexpected if Einstein’s theory of general relativity is applied to regions of extremely high density.

Charap is able to tie these almost surreal developments to the practical, bread-and-butter physics of spectroscopy. Of course, atomic physics is anything but intuitive. He therefore describes the fundamental tenets of quantum mechanics in an attempt to provide a flavour of the practical and conceptual consequences of the revolution led by Max Planck, Erwin Schrödinger and Werner Heisenberg.

The author summarizes the developments of high-energy physics, and describes the successes and surprising predictions of contemporary cosmology. He also briefly mentions the wonder of chaos theory, and has a stab at summarizing string theory and its daughter (or mother) M-theory. By successfully interlacing the theoretical principles with experimental facts, Charap gives the whole endeavour a robustness that reflects his joy and pride at taking part in such an intellectual exercise. He has great respect for the academic tradition and the thinkers who built up this edifice. Explaining the Universe is therefore peppered with wonderful historical anecdotes about the (mainly) men who made these discoveries. These stories help to make the book a good read.

Charap’s main challenge has been to compress vast amounts of scientific information into a text that must be, at the same time, understandable and entertaining. I am not sure that he always succeeds. For each chapter, Charap’s approach is to describe a couple of concepts carefully and then merely enunciate a string of others. Although his in-depth explanations are exemplary, this policy makes for an uneven read.

The cover, for example, states that the book will help the non-physicist to “accept as commonsensical Heisenberg’s uncertainty principle”. While Charap does present a lucid explanation of this mind-boggling concept, I doubt whether the reader will understand all of the remaining ideas discussed in the book.

It is in the epilogue that one of the more questionable aspects of modern science plays itself out. Charap has decided – “perhaps rashly” – to make “some predictions about what the 21st century will bring”. He thus compiles a long list of what he believes are the likely outcomes of research projects at the beginning of the millennium. From accelerator experiments to astronomical observations, Charap predicts with surprising confidence what will be discovered. In doing so, he gives what I believe is a misleading picture of what research is all about.

According to Charap, the experiments will find what they were set up to reveal, the theoretical problems of our age will be answered, and science will progress in a neat and orderly way. Although Charap does admit that there will be some surprises, this chapter voices the collective wish of the scientific community that somehow “things will be alright” and that our tremendous research efforts will be vindicated, a testament to our wise scientific choices.

His comments remind me of a seminar I attended a few years ago by the leader of one of the groups attempting to pin down the value of the Hubble constant using Cepheid stars – a method that is lucidly described in Charap’s book. Her group was consistently getting higher values than another group using different methods. At the time of her seminar, the difference between the results of the two groups was getting smaller. But when asked if she believed that the findings of both groups would ultimately converge, she – quite rightly – replied: “How could I possibly ever answer such a question? It’s not up to us.”