Judgement Day

Science of Discworld #4

by Terry Pratchett, Ian Stewart, Jack Cohen

The wizards of Unseen University are again called upon to defend their creation, Roundworld, this time in a courtroom—where its very existence hangs in the balance.
 
The Omnians fervently believe that the world is round, not flat, and view the discovery of Roundworld as a vindication of their faith. To leave this artifact in the hands of the wizards would be unacceptable. Not only do the academics hold that Discworld is flat, but by creating the Roundworld universe, they have elevated themselves to the level of gods. Ankh-Morpork’s venerable tyrant Lord Vetinari agrees to a tribunal, where the wizards Ridcully, Rincewind, and Ponder Stibbons can present their case—with key assistance from a Roundworld librarian named Marjorie Daw.
 
JUDGMENT DAY weaves together explorations of such Earthly topics as big science, creation, subatomic particles, the existence of dark matter, and the psychology of belief--a treat for Discworld fans and readers of popular science alike.


From the Trade Paperback edition.

Genres: Fantasy, Fiction, Humor, Comedy, Audiobook, Science Fiction, Popular Science

342 pages, Hardcover

First published April 11, 2013

About the author

Sir Terence David John Pratchett was an English author, humorist, and satirist, best known for the Discworld series of 41 comic fantasy novels published between 1983–2015, and for the apocalyptic comedy novel Good Omens (1990), which he co-wrote with Neil Gaiman.
Pratchett's first novel, The Carpet People, was published in 1971. The first Discworld novel, The Colour of Magic, was published in 1983, after which Pratchett wrote an average of two books a year. The final Discworld novel, The Shepherd's Crown, was published in August 2015, five months after his death.
With more than 100 million books sold worldwide in 43 languages, Pratchett was the UK's best-selling author of the 1990s. He was appointed an Officer of the Order of the British Empire (OBE) in 1998 and was knighted for services to literature in the 2009 New Year Honours. In 2001 he won the annual Carnegie Medal for The Amazing Maurice and His Educated Rodents, the first Discworld book marketed for children. He received the World Fantasy Award for Life Achievement in 2010.
In December 2007 Pratchett announced that he had been diagnosed with early-onset Alzheimer's disease. He later made a substantial public donation to the Alzheimer's Research Trust (now Alzheimer's Research UK, ARUK), filmed three television programmes chronicling his experiences with the condition for the BBC, and became a patron of ARUK. Pratchett died on 12 March 2015, at the age of 66.

Reviews

[Hayley · Rating 2 out of 5]

I have loved the previous science of the discworld books but this one really disappointed me. My first issue with it was the focus on religion. Although very respectful the constant argument against religion was to me a bit repetitive and not as interesting as some of the other scientific explanations and theories discussed in the other books. Maybe as someone with religious beliefs and a real interest in science the focus of this book did not sit comfortably with me. Maybe this links in well with me not liking my views being
challenged (something that is discussed in the book)but for whatever reason I just could not get as interested in this book as with the others in this series.
My second major issue with this book was the discworld sections. In the other books I have really loved the mixture of the scientific chapters interspersed with a mini discworld story, but this one just doesn't live up to my expectations. The story did not grip me and the characters just did not feel alive. Rincewind appears but could just be any old wizard. None of the characteristics/ personality of Rincewind shine through. I don't think that this will be a book that I will be tempted to read again.

[Max · Rating 4 out of 5]

I LOVE THE SCIENCE OF DISCWORLD. These books are the ultimate enjoyment for me, fantasy mixed with learning. Some passages can be quite slow, and sometimes I found myself longing for a Terry Pratchett chapter again, but it was all good.

[Gerd · Rating 2 out of 5]

Wow. What a disappointment.

The major flaw with this installment of the 'Science of Discworld' series is that it is not really a 'Science of Discworld' book. The Discworld part is very small and - frankly - badly written. It makes one wonder whether Terry Pratchett was really much involved with writing those parts.

The science parts of the book suffer from a. being too long b. no clear structure c. swinging wildly between being too detailed and being to general.

The overall book feels like someone just wanted to bash religions - or more likely get back to someone who is religious and wasn't very nice about it.

Don't get me wrong, I am all in favor for showing clearly that religions are a relic from the past, that shouldn't exist anymore in our rational, 'enlightened' time.

But the style of saying over and over again that proponents of religion are simply dumb morons doesn't help.

The book has no clear objective, there are no real ideas, information or action proposals on how to change the situation.

In contrast to especially books 1 and 2 of the series, it just seems like someone has a grudge and wanted to write his frustrations away.

What a pity - given the scientific facts, history of science and insights into current scientific developments, it could really have been a great book.

[Alex Sarll]

I have a few books called The Science of Superheroes, The Science of Doctor Who and the like. The sort of thing I'd hardly not pick up from the free box, but I've never read any of 'em - because I know it'll just consist of 'The science in this source is lousy, but here's a thing which is sort of vaguely similar'. The Science of Discworld is an altogether different beast. Because Discworld never even pretended to run on scientific principles, so what you get instead is our world being accidentally created in a pocket universe within Discworld, and then peered at from without (or interfered with) by the wizards of Unseen University - a bit like Lovecraft's elder gods, but generally benevolent and much more concerned about missing lunch. So the popular science book by Stewart and Cohen (themselves pretty good at this sort of thing) hangs off the spine of a Terry Pratchett novella - and one featuring my favourite Discworld characters, at that.
This mix worked brilliantly for three books - each covering a defined and pretty separate area of science, each with a good little wizards story as a springboard for the principles. Here, I'm not so sure. The editing doesn't help - there's repetition, and sentences that are clearly missing important parts, though unusually it gets better as the book goes along (my usual experience is that errors accumulate more towards the end of a book - presumably because whoever is meant to be looking for them lost interest, or had to rush to meet a deadline). But even beyond that, I'm not sure the overall concept of the book was clear enough. In places it's updating the science from the previous books which has now become outmoded, which is fair enough - and in turn using that to illustrate the wider principle of how science, presented with new facts, changes its mind (a process they admit isn't always perfectly adhered to, but is nonetheless done with better grace than certain other world-views manage). Some of the stuff in this is really interesting - especially the new understanding of ribosomes as potentially more important than DNA, or the debunking of the 'Goldilocks universe' idea, showing how the idea that our universe is somehow perfectly adapted for our existence is based on several false premises and proves precisely nothing. Elsewhere, though, they're basically joining in the culture wars against creationist arses. Now, I'm all in favour of creationist-bashing - ideally with something like this - but it can all feel rather like preaching to the choir (inappropriate metaphor chosen deliberately). I suppose part of the point is that Science of Discworld books sell even in places that don't sell many books (eg my little local Tesco), and to people who wouldn't (be allowed to) buy The God Delusion, but it still involves going over some old ground for the rest of us.
And then, to hang that off, you have the Pratchett novella. In which the Omnian church (who live on Discworld, but insist it's spherical) learn of Roundworld's existence, and claim ownership of it. This would be fine if Pratchett hadn't reformed them into a basically decent church many books ago, meaning he now has to dig out a fundamentalist offshoot, make them far more powerful than seems plausible under the circs, yet still have the main church kick against them in precisely the way even the blessedly mild CofE fails to do against their christian equivalents. A court case follows, which in its speechifying and consistent wish fulfillment feels less like Pratchett and more like popular liberal wankfest The West Wing.
This book's intentions are good, but they're insufficiently clear, and the execution was definitely fumbled.

[Eleanor · Rating 3 out of 5]

3.5 stars.

This was the first new-to-me Discworld content I’ve read in a while, so I was super excited to dive back into one of my favorite fantasy worlds. As I think a lot of other reviews have mentioned, the scientific content of this book was a lot less hard science and more psychology of belief stuff—aka why people believe in or don’t believe in God, aka (because this book was written by three atheists) a methodical takedown of the concept of belief in a higher power in general.

Now, that wasn’t the whole of Ian Stewart and Jack Cohen’s contributions to the book. There were several chapters that hardly included any religion v science content. I was especially fascinated by the parts on quantum superposition, the size and shape of the universe, and the RNA world hypothesis, as well as some great digressions on subatomic particles, topology, and statistics. And Stewart and Cohen state that science and religion can and should coexist, moderates in both camps recognize that a lot of the bad blood between them is unnecessary and harmful, and religions often promote good morals. (A couple of anecdotes throughout the book also seem to indicate that Cohen, despite no longer believing in the theological aspects of Judaism, still finds great value in the cultural aspects of that community.) But although the authors state those things a few times, that’s not the predominant tone of the book or what mainly comes across. The idea that belief in a higher power is fundamentally irrational and results from a fundamentally irrational approach to the idea of knowledge is the theme that weaves together this book. Even if it’s not the central focus of every chapter, it’s usually in the background. This theme is also very heavy-handedly and explicitly communicated through the main character, Marjorie, and some of her speeches and actions. It felt sometimes like the Discworld side of the story was just constructed to, for lack of a better phrase, shove this message in people’s faces, instead of letting the themes the authors wanted to communicate spring organically from well-developed plot and characters.

I’m not religious, but I still didn’t like how condescending the whole book came across. I don’t think it intended to be that way, but I also think it’s difficult for many nonreligious people (myself included sometimes) to discuss religion without incredulously thinking something like how the hell could you believe in an imaginary man in the sky, which just means we have to pay extra attention to our rhetoric and make sure we’re communicating respect for religious people as human beings even if we don’t agree with their belief system. I feel like this book didn’t really do that. Even though it made some good points (ex. debunking common misinterpretations of the nature of scientific inquiry), those got lost in the rather grating tone.

Another gripe I have with the science side of this book is that it almost doesn’t seem to be sure of its audience. As I mentioned, some of the chapters were filed with great, more technical scientific content. But substantial portions of them were dedicated to explaining that the Earth isn’t flat, and evolution does indeed exist, and the Earth is more than 10,000 years old, and so on. Which I understand some people might not believe, but to me, it was all so . . . basic? Like half the book was a Beginner’s Guide to How the Universe Works for religious people, whom Stewart and Cohen seem to think were born yesterday, and half the book was highly technical equations about the volume of hyperspheres that you have to take a Khan Academy break to understand. It was like the book wanted to have as large an audience as possible, so it included stuff for everyone, despite the fact that half of the its content would be ridiculous to most readers.

All that being said, I did still enjoy reading this book. Aside from all those gripes, there were many aspects I enjoyed. I liked the more hard sciencey chapters (particularly the parts that got into biochem and microbiology, though that’s just me). I also loved seeing many of our favorite Discworld characters back at it again, particularly Ridcully, Vetinari, and Ponder. (I thought Rincewind fell a little flat, which was sad, because Interesting Times was my first Discworld book and Rincewind was my favorite Discworld character for a long time.) The cameo from Angua was also a nice treat :)

On the whole, I’d give the Discworld side of this book about a 4/5, and the science side more like a 3/5. Thus, my rating.

I really wanna go back and reread some old Discworld books now. Maybe Night Watch or Thief of Time? We’ll see :)

Please feel free to comment on this review, as with all my others, but let’s be extra conscious about keeping the tone respectful and calm. If you really need to rant, hmu in those Goodreads email messages :)

[Silent_count · Rating 3 out of 5]

I wasn't expecting to see another "Science of Discworld" and was excited when I learned of it's existence. Then unfortunately, I read it.

In terms of subject matter, "Judgement Day" is certainly the most advanced of the "Science of Discworld" series. While it does retread some of the ground covered in the earlier books, this one takes a closer look at some of the big questions our scientists ask of the universe. How did it all begin? Where is it going? What actually is the shape of the universe? And how close are we to answering any of these questions?

All interesting enough but Messers Cohen and Stuart seem have stumbled into the same pit which Richard Dawkins has long since disappeared into. You see the problem is thus: faith is belief despite the absence of evidence. People who have faith are not going to be swayed by pointing out the absence of evidence, nor by the existence of evidence contradicting their faith, because if they were the kind to be swayed by such things, they wouldn't have their faith-based beliefs to begin with. Yet, intelligent and knowledgeable as they are, Cohen and Stewart fail to wrap their collective mind around that line of thought so they subsequently devote countless pages to the folly of providing evidence and logical arguments that religion is not consistent with the scientific method. We all know, but the faithful just don't care!

Sadly the "Discworld" chapters of the book both compound, and are a reflection of, the mistakes made by the "scientific" chapters - they try to preach science to the faithful. As a result, they seem disjointed. More a description of a series of events rather than a story with a plot.

There some interesting and worthwhile topics discussed in this book, so if you have an interest in science... well, there are still better books out there to take a look at. However, if you like science and enjoy the view from a turtle-shaped world, there are worse ways you could spend an afternoon.

[Manu · Rating 5 out of 5]

No tengo aquí los anteriores de Ciencia del Mundodisco, pero me ha dado la sensación de que los capítulos de trama —los escritos por Pratchett, vamos— son mucho más cortos en este libro. Aun así, hay cameos para dar y vender: sale hasta Sally, que ha ascendido bastante en la Guardia desde la última vez que la vimos.

Pero Stewart y Cohen son muy buenos divulgadores. El hilo conductor del libro es la creencia y sus distintos sistemas, poniendo el acento en distinguir entre el pensamiento centrado en humanos y el centrado en el universo. Sin embargo, para enfocarlos desde diversos puntos de vista, sus autores hablan entre otras cosas de evolución, antropología, exobiología y, claro, cosmología (con un fuerte componente topológico que, como dice A.S. Byatt, lo vuelve el único capítulo algo más difícil de entender). Al igual que en los libros previos de ciencia del Mundodisco, los autores dan un pequeño repaso al estado actual de distintas ramas del saber científico, desmontan unos cuantos mitos muy arraigados y casi (¡casi!) hacen que te dé igual lo cortos que son los capítulos de trama mundodisquera.

Iba a incluir dos o tres citas para acabar, pero hay tantas que no me decido. Leedlo.

[John Dunlop · Rating 3 out of 5]

I like this series of books. The scientific parts are very accesable and just as good as the fiction parts.
On this particular book, not so much.
The science was still as educational and amusing as it always was.
The discworld part..........well...........look i know Terry Pratchett is not a well man and I take my hat off to him, the last few books he's written have surpassed my expectations, but on this book I get the impression his name is being used as a marketing tool. The discworld sections only amount to three or four pages each and amount to nothing more than a synopsis for a story.
I enjoyed the book, but I think my expectations were too high.

[Florin Pitea · Rating 4 out of 5]

Rather less focused than the previous two books in the series, but a pleasant and instructive read nonetheless. Recommended.

[Barb Middleton · Rating 3 out of 5]

This didn’t have enough of the fantasy world intertwined with the dry science facts. The end spends a long time on beliefs and religion which was interesting. If you are interested in a counter argument read the book, The Language of God, that blends science and beliefs and written by a scientist. I do agree with the authors in this book the belief doesn’t mean not thinking critically about beliefs and blindly following spiritual leaders to serve one’s self interests. Our cultural failures are often driven by hubris and reflection is important to growth as human beings.

[Chris Boulton · Rating 4 out of 5]

.. and so passes another ending of a Discworld related series.. guess I'm gonna have to get used to that seeing as, you know, he's no longer with us, mortal coils and all that.

It's been a while since I delved into the Science of Discworld books.. tbh I think I probably should have re-read the first three - as a refresher - and then read this one but hindsight is an amazing thing. What I do remember though is distinctly preferring the "Discworld chapters" more than the "Science Chapters". I was younger and still pretty new to the Discworld so I think part of me just wanted to read another DW novel but was disappointed to discover he was there to learn things.. maths, science and stuff like that - "UGH!" said younger me, "I get enough of that at school!"

There is also the issue that I'm not all that bright... sure, I can pull out good bits of information (generally useless but interesting, I think) when occasionally some discussion kicks off a memory of an episode of QI and I'm like "did you know that the Blue Whale's testicles holds.. " or "they can only swallow things the size of a grapefruit?!".. but if you want proper science-y or maths-y intelligence then I'm not your man.

Annnyway.. my point is that in this particular edition of the SoDW.. I think I actually preferred the "Science Chapters" (SC) to the "Discworld Chapters" (DWC). The DWCs were too short and fragmented for my liking .. I remember the story being quite involved and enjoyable in the previous books.. here they just felt like fillers until you got to the SCs. But the SCs were informative, enjoyable, funny and - being not particularly bright (as mentioned previously) - largely understandable.. even if I had to read them twice, occasionally thump the side of my head while screaming "HELLO? IS ANYONE THERE?!" or simply shrug and move on sometimes.

Might have to go on the "retrieve from the parent's house for a reread" list.. maybe. Anyway, now I'm starting a new trilogy that I'm not all that excited about attempting.. but I think it's probably time to give it a go... "The Hunger Games".

[Jc · Rating 3 out of 5]

This is the first of the Science of Discworld books I have read. I am sorry to say I was somewhat disappointed in it. Coming from a science background, having read and enjoyed many "Science of..." and "Philosophy of..." books, and being a BIG fan of Discworld and other Pratchett writings, I was excited to read this. But, I felt the authors constantly waffled regarding who their audience was. The result was that sometimes it was way too dense, or assuming too much background knowledge on the part of its readers, while at other times it was way too simplistic for any one with even a high school level of science (esp. Physics and Biology) knowledge. I could have enjoyed the book if it stuck to either the simplistic, introductory level, or if it had consistently spoke to an audience with a basic background in the subject matter. However, the often abrupt changes in tone was off-putting. At the same time, many section were fascinating and well-constructed. So, I had mixed feelings. I will probably read at least one of the earlier ones, as many who have read the previous three think this is the weakest of the series so far. Maybe I was just expecting too much.

[Gosia · Rating 5 out of 5]

Now! Now we are talking!
I knew I was persistent with reading the Science of Discworld for a reason, I know why I don't give up on book or series I start!
I started my adventure with Discworld with Rincewind series, so normal was my reason to get to Science. The problem is.. I'm 100% humanist. Like, learning languages. Like reading books. Like learning about religions/history.
I'm not really a science person, I was happy when biology ended in high school and almost burnt all my math books(thank Godness I didn't do it, I'm financial analyst now, but you get my point, right?)
Reading three parts of Science taught me quite a lot, I didn't know all these stuff, but it was kinda.. well, not boring, but not that amusing as it should be.
This one though, even if it's talking about THAT things also, IS AWESOME, kay? Loved every single page of it. Humor is witty, the Authors are talking about themselves - which makes it cool - plus The Mags story with Ms Librarian is really cool too. Awesome one.
Now, off I go to the Witches series. #YESSSSS

[Adi · Rating 2 out of 5]

Finally! I thought I would never finish it...
Honestly, I was quite disappointed with this book. As with the previous "The Science of Discworld" novels, it is also split into two separate tracks - a Discworld story and a more scientific part.
The Discworld bit was not memorable, in fact it was bordering boring. I could not find any of Terry's brilliant humor and unmatched imagination in there. On the other hand, the science chapters were so incoherent, lacking structure, lacking logical sequence and oh..so, so long...
I am glad I can move to some of Terry's better works now.

[Robert · Rating 5 out of 5]

As with the previous volumes of the Science series, Pratchett explicates and also deflates a range of science topics. Nothing is sacred to his analysis and wit, not even Round World science. It's been decades since I've had an actual college level "science" class in chemistry, biology, physics, astronomy, or even math, so his explanations of cutting edge science and it relation to the history of science and the nature of belief systems, is extra interesting, and challenging. Fortunately, I've read a fair amount on several of the topics he covers, so I at least have a simple notion of where he's going.

[Nicole · Rating 3 out of 5]

Mit dem vierten und letzten Band der Reihe "Wissenschaft der Scheibenwelt" habe ich nun nach mehreren Jahren die Reihe endlich abgeschlossen. Das Sachbuch-Fantasy-Genre-Mix ist unterhaltsam und informativ allerdings stellenweise zu detailliert für meinen Geschmack. Eine Empfehlung nur für echte Scheibenwelt-Fans.

[Margaret Mackley · Rating 3 out of 5]

Not a lot of Terry Pratchett in this. Good scientific explanations by the other authors. I'm not sure that a religious person would enjoy this, but I found the debate between the human centred (religious) view of our world v the universe centred (scientific) view quite entertaining. I still got a bit bogged down in the science parts at times and wished there was a bit more of Discworld in the book. Thought provoking nevertheless.

[Vladimir Putin · Rating 3 out of 5]

I got judged at school today and I dranlk water :(

[Tomasz Blaszak · Rating 2 out of 5]

Nie ma tej pratchettowej energii, błyskotliwości co poprzednie części "Nauki Świata Dysku", niestety. Tematy znów ogromne, a finezji jakby mniej, jakby w lekkim chaosie. Szkoda

[Shriya Uday · Rating 3 out of 5]

Too much physics. Also Richard Dawkins stuff showed up and I don't care for that.

I did love the Discworld stuff though, especially knowing that Angua and Sally patrol together

[Ryan · Rating 3 out of 5]

a bit too heavy handed as these things go. Needed more Discworld and less physicists disproving god

[Eric · Rating 3 out of 5]

This review applies to The Science of Discworld volumes I-IV. Overall, I'd give these a 3.5. We've all run into books titled "The Science of...". These sad volumes generally try to coerce some vague relationship between current scientific theories and whatever key narrative elements (hyperspace, transporters, etc.) are hallmarks of the host series' stories.
The Science of Discworld books are something else entirely. They start with the assertion that a flat world riding through space on a turtle is the only reasonable design. There is, therefore, no need to explain it. When the wizards on Discworld accidentally create a non-magical universe that seems to work on spherical principles ("Roundworld"), there is a great deal to explain. How does a non-magical universe work with nothing to tell it how things should be?
The books are one part Discworld story, used primarily as a framing device, and one part detailed science primer - not of the Disc, which needs no explanation, but of our own world. Subatomic physics, scientific method and history, evolution, culture, biology, and other topics are covered in a narrative non-mathematical way. Generally the coverage is solidly reasoned and very clearly explained.
While both the stories and the science are serviceable, neither are spectacular - with one exception. The authors present a recurring argument that homo sapiens should actually be named pan narrans - "the storytelling ape". They make the case that our apparently unique ability to tell stories, factual, representational, counterfactual, and otherwise is the driving force behind the human endeavors of culture, science, and religion. It's a fascinating and convincing assertion.

[Laurie · Rating 3 out of 5]

This volume of the Science of Discworld books goes over evolution, cosmology, and religion, among other things. The discussion of these things is presented if fairly straightforward terms that most readers will be able to understand without having to resort to Google too often. I’ve read several books on quantum physics and cosmology (and still remain boggled by the subjects) and have to say this book puts in a very understandable way. The heart of the book, though, is a thread that runs through all the subjects, and that is why do people believe in things that cannot be proved scientifically. Why do some cling to young earth theories that geologists assure them are not true, or feel that their religion, and only their religion, is real and true despite *not* being able to prove it? Their answer is that religion is human-centered, even though it tries to explain universe centered things. A human centered world view concentrates on the smaller things, on a human scale. Science says the universe is huge, cold, and doesn’t give a damn about humans. A universe centered view offers no comfort.

Like the other SoD books, the science is strung together with a weak Discworld story. And it’s very weak in this book. A couple of pages of story at the start of every chapter makes it a very short story, and it has no plot arc. A fair number of Discworld characters put in appearances, but it’s like they are just wheeled out to wave at the crowd and be gone. If you’re looking for an overview of the sciences presented in this book, it’s fine. But don’t expect a real Discworld story.

[D.L. Morrese · Rating 4 out of 5]

I'm not sure how much of this was written by the late, great Sir Terry, but I didn't see much of his signature wit in it. It is, however, a fine overview of how a scientific perspective differs from a mystical perspective. Science, the authors claim, is universe-centered. We are a consequence of the way the universe is. Mysticism and religion tend to be human-centered, placing Man (somewhat arrogantly) as the reason for the nature of the universe. Obviously, there is much discussion about the Anthropic Principle (both Strong and Weak). They also challenge the claim that science is a belief system, not unlike that of religions. The key reason it's not is that virtue in religious belief systems is gauged by faithful acceptance of the dogma/scriptures/dictates of the religion and accepting them as true. In science, the greatest virtue comes from challenging current beliefs and discovering ways in which they are flawed.

[Sara · Rating 1 out of 5]

I stop part way through. It's not a story like other Terry Pratchett books. It more like weird bits of info about actually science and their opinions of them. It reads too much like a textbook and not enough like a novel.

[Neil · Rating 1 out of 5]

First of all, it's not 'a brilliant new Discworld novel'.
It's a rather dull treatise on physics by two blokes who are NOT Pratchett, with interposing passages by the great man to give it a touch of entertainment value. I didn't read the first three, I'm happy to say.

[Ruth · Rating 5 out of 5]

Why can't all scientific explanations be as straightforward as the writing in this book?

[Skyring · Rating 5 out of 5]

I registered a book at BookCrossing.com!
http://www.BookCrossing.com/journal/14321943

[Peter Dunn · Rating 4 out of 5]

While this is the weakest of the four Science of Discworld books it’s merely the weakest of four fabulous books all of which will make you both laugh and think, often at the same time. It is just that this one will make you do so fractionally less than the other three.

Why do I think it is just a tiny bit weaker than the others? Two reasons: -

Firstly Terry’s Discworld sequences in this book feel less substantial than in the previous three books. They are probably exactly the same length as before but the overall story seems slightly weaker and less engaging than the others. Of course any Terry Pratchett Discworld stuff is sure to amuse, entertain and make you think, and this does all those things but just a little less powerfully that usual.

Secondly Jack and Ian’s sections focus this time on religion and in particular how more extreme or dogmatic versions of religion may actually impede good thinking or even science itself, both as a thought process and as an endeavour. This is fine except this time that one topic seems to be the almost single focus to the exclusion of all else. In the previous three books Ian and Jack were able to be much more discursive, fitting in thoughts on many other things without losing the thrust of their main thesis, and they had also covered some of the same ground on religion in books one and two. So, as I have said, these sections are well worth reading, and will challenge your thinking, but marginally less so than the previous three books in the series did.

So I need to make two declarations of interest here. First Terry and Jack are/were both researchers at the University of Warwick which also currently employs me, so than might perhaps bias me a tadge. Secondly I (as Terry, Jack and Ian knows/knew) am a very bad Evangelical Christian so that might bias me a little in the opposite direction.

However I know Jack and Ian won’t think that I am carping too much here as an Evangelical because as they amusingly noted in Science of Discworld 2:

‘So let us begin by acknowledging, as we did towards the end of The Science of Discworld, that 'all religions are true, for a given value of true' '

And they also noted in the same book:

‘If you are religious, and you want to feel comfortable about what we're saying, you can always assume that we're talking about all the other religions, but not yours.’

So I will assume that then….. :-)

I am saddened to be writing this in same month that Jack passed away. He will be missed but thankfully we still have the many great publications he left us - including this book. GNU Jack. GNU Terry.

[Dan'l Danehy-Oakes · Rating 4 out of 5]

By Terry Pratchett, Ian Stewart, and Jack Cohen

As with its three predecessors, this is a Discworld novella by Pratchett of several chapters, which alternate with chapters musing on various scientific matters by Stewart and Cohen.

The story in this one is probably the best of the four in this series. The wizards in Unseen University's High-Energy Magic department build a Great Big Thing, which interferes with Roundworld (our universe, created by the HEM wizards in the first volume); it causes the unfortunately named Marjorie Daw, a librarian -- what else? -- from Roundworld to be transported to Unseen U, a place where no women are allowed. Well, except the chars and cooks and so on. This gives us the ability to see familiar aspects of Discworld as if for the first time, which is entertaining in and of itself.

Adding to the fun, the reactionary faction of the Omnian priesthood -- familiar from _Small Gods_ -- is claiming ownership of Roundworld on the grounds that the idea of the world being round rather than flat is their intellectual property, they having believed and taught this on the Disc for thousands of years.

However, the majority of the book is by Stewart and Cohen. They are entertaining science writers, with a wit that, if not as sharp as Pratchett's, is quite able; but they go on at length. I would estimate that at least 3/4 of the book is by them.

And the problem is that they have bones to pick. They are, for example, scientistic triumphalists -- that is, evangelical atheists, people who are as annoyed by the stubborn ignorance of a religionist as a religious evangelical tends to be by the stubborn ignorance of an atheist. Make no mistake, I have no patience for anti-science religionists; but I have none for anti-religion atheists, either. Intolerance is intolerance, unless, of course, it's intolerance of things I don't approve of (like intolerance), in which case it's just fine.

But most of their contribution is fine, with amusing tidbits of scientific history blended with mostly math-free explanations of what seems to be going on in the universe (or what seemed to be, back around 2010 or so when a book published in 2013 would have been written).

So, mostly enjoyable.