Skip to main content

Once upon and Algorithm - Martin Erwig ***

I've been itching to start reading this book for some time, as the premise was so intriguing - to inform the reader about computer science and algorithms using stories as analogies to understand the process.

 This is exactly what Martin Erwig does, starting (as the cover suggests) with Hansel and Gretel, and then bringing in Sherlock Holmes (and particularly The Hound of the Baskervilles), Indiana Jones, the song 'Over the Rainbow' (more on that in a moment), Groundhog Day, Back to the Future and Harry Potter.

 The idea is to show how some aspect of the story - in the case of Hansel and Gretel, laying a trail of stones/breadcrumbs, then attempting to follow them home - can be seen as a kind of algorithm or computation and gradually adding in computing standards, such as searching, queues and lists, loops, recursion and more.

 This really would have been a brilliant book if Erwig had got himself a co-author who knew how to write for the public, but sadly the style is mostly heavy academic, so the cleverness is rather wasted. Sometimes this comes across in labouring points and at others in spending a lot of effort on what is little more than defining labels for things, rather than providing useful information and context for the reader. It's not that there's not a lot of good material in there, just that it's hard work to dig it out, where I'm sure the whole idea of using the stories was to make it more approachable.

 Part of the problem is that the stories themselves don't always work very well as an analogy for what's happening in the computation. So, for example, in the section dealing with sorting he comes up with the task of sorting the tasks and places that Indiana Jones needs to deal with to find the Lost Ark. The unsorted list includes the likes of: disc, sunbeam, Marion and Nepal. The algorithm used involves finding the 'smallest' element... which somehow we are supposed to instantly see is Nepal. Using numbers would not have been so well-linked to the story, but at least it would have made some sense to the reader.

 Perhaps the low point is the section that uses a part of the song 'Over the Rainbow' (giving us a tenuous story connection to The Wizard of Oz) to examine language and meaning. If you aren't familiar with musical notation, I'm not sure it's a very helpful analogy... and if you are, some of the ways it's used (particular the assertion of what bars are for) doesn't entirely make sense.

 I was a professional programmer for a number of years, but without a computer science background. So I was very familiar with how to do this stuff, but knew nothing of the theory behind it. As such, I found the content of the book really interesting - and the story idea should have made it doubly brilliant - but the execution meant that it didn't deliver anywhere near as well as it could have. Even so, there's a lot to savour, and it's definitely worth persevering to get a feel for why computer programs involve far more than just 'cutting code.'
Hardback:  

Kindle:  

Using these links earns us commission at no cost to you

Review by Brian Clegg
Labels:

Comments

Post a Comment

Popular posts from this blog

Roger Highfield - Stephen Hawking: genius at work interview

Roger Highfield OBE is the Science Director of the Science Museum Group. Roger has visiting professorships at the Department of Chemistry, UCL, and at the Dunn School, University of Oxford, is a Fellow of the Academy of Medical Sciences, and a member of the Medical Research Council and Longitude Committee. He has written or co-authored ten popular science books, including two bestsellers. His latest title is Stephen Hawking: genius at work . Why science? There are three answers to this question, depending on context: Apollo; Prime Minister Margaret Thatcher, along with the world’s worst nuclear accident at Chernobyl; and, finally, Nullius in verba . Growing up I enjoyed the sciencey side of TV programmes like Thunderbirds and The Avengers but became completely besotted when, in short trousers, I gazed up at the moon knowing that two astronauts had paid it a visit. As the Apollo programme unfolded, I became utterly obsessed. Today, more than half a century later, the moon landings are
Post a Comment
Read more

Space Oddities - Harry Cliff *****

In this delightfully readable book, Harry Cliff takes us into the anomalies that are starting to make areas of physics seems to be nearing a paradigm shift, just as occurred in the past with relativity and quantum theory. We start with, we are introduced to some past anomalies linked to changes in viewpoint, such as the precession of Mercury (explained by general relativity, though originally blamed on an undiscovered planet near the Sun), and then move on to a few examples of apparent discoveries being wrong: the BICEP2 evidence for inflation (where the result was caused by dust, not the polarisation being studied),  the disappearance of an interesting blip in LHC results, and an apparent mistake in the manipulation of numbers that resulted in alleged discovery of dark matter particles. These are used to explain how statistics plays a part, and the significance of sigmas . We go on to explore a range of anomalies in particle physics and cosmology that may indicate either a breakdown i
Post a Comment
Read more

Splinters of Infinity - Mark Wolverton ****

Many of us who read popular science regularly will be aware of the 'great debate' between American astronomers Harlow Shapley and Heber Curtis in 1920 over whether the universe was a single galaxy or many. Less familiar is the clash in the 1930s between American Nobel Prize winners Robert Millikan and Arthur Compton over the nature of cosmic rays. This not a book about the nature of cosmic rays as we now understand them, but rather explores this confrontation between heavyweight scientists. Millikan was the first in the fray, and often wrongly named in the press as discoverer of cosmic rays. He believed that this high energy radiation from above was made up of photons that ionised atoms in the atmosphere. One of the reasons he was determined that they should be photons was that this fitted with his thesis that the universe was in a constant state of creation: these photons, he thought, were produced in the birth of new atoms. This view seems to have been primarily driven by re
Post a Comment
Read more