Skip to main content

Time Travel: a writer’s guide – Paul J. Nahin ***

Time travel is an absolutely fascinating aspect of physics, if only because few people realize that it’s not fantasy – not only does time travel fail to break the laws of physics, we even have to deal with (very small scale) time travel on the part of GPS satellites to make them work properly. Paul Nahin doesn’t point this out, quite possibly because this is a surprisingly old book – although reissued in 2011 with a new preface, it dates back to 1997.
GPS might not have been part of everyday life back then, but most of the time travel science has survived pretty well unchanged. There are a few time-based omissions. No mention of superluminal tunnelling experiments or laser-based frame dragging, for instance. But the biggest omission in the science due to the age of the book has nothing much to do with time travel – it’s the casual dismissal of the cosmological constant, showing a predating of the discovery of dark energy. But luckily this is more a side-comment than of any great significance.
Apart from those small omissions, Nahin does a great job of getting through all the possibilities in a reasonably compact way. However, the way the book is tightly targeted means that it isn’t the ideal popular science book on time travel for the general reader. This is very much aimed at would-be writers of science fiction, and this comes through very strongly, both in Nahin’s remarks and in his approach which relies on many, many examples of science fiction stories featuring time travel. I’m quite a fan of science fiction, but I have to confess I found it heavy going with so many fictional references.
There are a couple of other tiny problems with the book. The science is mostly put across in a friendly fashion, but there are two times when Nahin goes into much too much detail, in a way that may well put off a lot of readers (particularly if they are looking at this as authors rather than would-be scientists). The other problem I had was a rather hectoring tone – at times he almost says that people with certain ideas (e.g. having problems with the killing-your-grandfather type paradox) are idiots because the paradox obviously won’t happen. I’m sorry, it isn’t obvious, and taking this approach is not particularly helpful.
Overall, then, a good if rather dated summary of the science of time travel, but because of the way it is put across only really of interest to serious SF fans or would-be writers (which, to be fair to the author, is exactly the audience that it is aimed at).

Paperback:  

Kindle:  
Using these links earns us commission at no cost to you
Review by Brian Clegg

Comments

Popular posts from this blog

Models of the Mind - Grace Lindsay *****

This is a remarkable book. When Ernest Rutherford made his infamous remark about science being either physics or stamp collecting, it was, of course, an exaggeration. Yet it was based on a point - biology in particular was primarily about collecting information on what happened rather than explaining at a fundamental level why it happened. This book shows how biologists, in collaboration with physicists, mathematicians and computer scientists, have moved on the science of the brain to model some of its underlying mechanisms. Grace Lindsay is careful to emphasise the very real difference between physical and biological problems. Most systems studied by physics are a lot simpler than biological systems, making it easier to make effective mathematical and computational models. But despite this, huge progress has been made drawing on tools and techniques developed for physics and computing to get a better picture of the mechanisms of the brain. In the book we see this from two directions

The Ten Equations that Rule the World - David Sumpter ****

David Sumpter makes it clear in this book that a couple of handfuls of equations have a huge influence on our everyday lives. I needed an equation too to give this book a star rating - I’ve never had one where there was such a divergence of feeling about it. I wanted to give it five stars for the exposition of the power and importance of these equations and just two stars for an aspect of the way that Sumpter did it. The fact that the outcome of applying my star balancing equation was four stars emphasises how good the content is. What we have here is ten key equations from applied mathematics. (Strictly, nine, as the tenth isn’t really an equation, it’s the programmer’s favourite ‘If… then…’ - though as a programmer I was always more an ‘If… then… else…’ fan.) Those equations range from the magnificent one behind Bayesian statistics and the predictive power of logistic regression to the method of determining confidence intervals and the kind of influencer matrix so beloved of social m

How to Read Numbers - Tom Chivers and David Chivers *****

This is one of my favourite kinds of book - it takes on the way statistics are presented to us, points out flaws and pitfalls, and gives clear guidance on how to do it better. The Chivers brothers' book isn't particularly new in doing this - for example, Michael Blastland and Andrew Dilnot did something similar in the excellent 2007 title The Tiger that Isn't - but it's good to have an up-to-date take on the subject, and How to Read Numbers gives us both some excellent new examples and highlights errors that are more common now. The relatively slim title (and that's a good thing) takes the reader through a whole host of things that can go wrong. So, for example, they explore the dangers of anecdotal evidence, tell of study samples that are too small or badly selected, explore the easily misunderstood meaning of 'statistical significance', consider confounders, effect size, absolute versus relative risk, rankings, cherry picking and more. This is all done i