Skip to main content

Small World – Mark Buchanan ***

It’s entirely possible for something to be both fascinating and intensely unsatisfying – and that is how I felt about Small World and the topic it covers.
The subject at the book’s heart is ‘small world networks’. This is the idea behind the famous (or infamous) concept of six degrees of separation. Based on an experiment by Stanley Milgram in 1970, the idea is that everyone in the world is connected to everyone else by no more than six links. The original experiment has been criticized for being limited to the US (hardly the whole world) and not taking in enough barriers of language, class and ethnicity – yet even when these are taken into account, there is a surprisingly small number of jumps required to get from most of us to most others.
What’s even more fascinating is that this type of network occurs widely in self-organizing systems, whether it’s the structure of the internet or biological food chains. What tends to crop up are networks where there are local clusters with a few long distance links, which drastically increase the chances of wide ranging connectivity. There isn’t a single style of these small world networks – some, for instance, have vast hubs with many spokes, while others are more democratic. (Interestingly, the internet, which was supposed to be democratic to avoid losing connectivity, as it was originally a military network that had to survive attack, has gone entirely the other way with huge hubs.)
What strikes me is the vagueness of it all. There seems to be an imprecision that’s most unusual for a mathematical discipline. This could be down to the way Buchanan is presenting things of course – his style is very readable but this does sometimes (not always!) bring a degree of smoothing over. Just as an example, we are told about Erdös in 1959 solving the puzzle of how many roads are required, placed randomly, to join 50 towns. Buchanan tells us ‘It turns out, the random placement of about 98 roads is adequate to ensure that the great majority of towns are linked.’ I’m sorry? What does about 98 mean? How about ensuring the vast majority are linked? That’s small consolation if you live in one of the towns that is isolated.
The other vagueness, in the ‘six degrees of separation’ model is what we really count as an acquaintance. It’s such a fuzzy concept, it’s hard to see just how it can be made to operate with the precision required by mathematics. I have nearly 1,000 people in my email address book. Are they all acquaintances? How about those lovely people on the Nature Network with whom I often exchange comments about blog entries, but none of whom have I ever met or spoken to, and only two have I ever emailed? For that matter, what about my ‘harvest’ emails? Is somebody an acquaintance because I’ve seen their email address? Probably not. How about when someone sends me an email and copies in lots of other people. Are those email addresses part of my contact circle? I don’t know – and I doubt if the people who play around with this interesting, but in some senses rather futile feeling, research do either.
Both these examples relate to why there’s an underlying lack of satisfaction. Like chaos theory, this is a concept where initially you feel ‘wow, this should give amazing insights’ because it’s so fascinating, but then it doesn’t. I’m reminded of Rutherford’s famous remark ‘All science is either physics or stamp collecting.’ Dare I say it – this feels a bit like stamp collecting.
Review by Brian Clegg


Popular posts from this blog

Four Way Interview - Tom Cabot

Tom Cabot is a London-based book editor and designer with a background in experimental psychology, natural science and graphic design. He founded the London-based packaging company, Ketchup, and has produced and illustrated many books for the British Film Institute, Penguin and the Royal Institute of British Architects. Tom has held a lifelong passion to explain science graphically and inclusively ... ever since being blown away by Ray and Charles Eames’ Powers of Ten at an early age. His first book is Eureka, an infographic guide to science.

Why infographics?
For me infographics provided a way to present heavy-lifting science in an alluring and playful, but ultimately illuminating, way. And I love visualising data and making it as attractive as the ideas are.  The novelty of the presentation hopefully gets the reader to look afresh. I love the idea of luring in readers who might normally be put off by drier, more monotone science – people who left science behind at 16. I wanted the boo…

Einstein's Greatest Mistake - David Bodanis ****

Books on Einstein and his work are not exactly thin on the ground. There's even been more than one book before with a title centring on Einstein's mistake or mistakes. So to make a new title worthwhile it has do something different - and David Bodanis certainly achieves this with Einstein's Greatest Mistake. If I'm honest, the book isn't the greatest on the science or the history - but what it does superbly is tell a story. The question we have to answer is why that justifies considering this to be a good book.
I would compare Einstein's Greatest Mistake with the movie Lincoln -  it is, in effect, a biopic in book form with all the glory and flaws that can bring. Compared with a good biography, a biopic will distort the truth and emphasise parts of the story that aren't significant because they make for a good screen scene. But I would much rather someone watched the movie than never found out anything about Lincoln - and similarly I'd much rather someon…

A Tale of Seven Scientists - Eric Scerri ***

Scientists sometimes tell us we're in a post-philosophy world. For example, Stephen Hawking and Leonard Mlodinow in The Grand Design bluntly say that that philosophy is 'dead' - no longer required, as science can do its job far better. However, other scientists recognise the benefits of philosophy, particularly when it is applied to their own discipline. One such is Eric Scerri, probably the world's greatest expert on the periodic table, who in this challenging book sets out to modify the philosophical models of scientific progress.

I ought to say straight away that A Tale of Seven Scientists sits somewhere on the cusp between popular science and a heavy duty academic title. For reasons that will become clear, I could only give it three stars if rating it as popular science, but it deserves more if we don't worry too much about it being widely accessible.

One minor problem with accessibility is that I've never read a book that took so long to get started. First t…