Back in the 1960s, I occasionally used to get access to a copy of Mad magazine. As a simple Dundonian lad I found a lot of it impenetrably American at the time, but I do remember being amused by a feature that purportedly gave examples of how publishers got the quotes for their book covers. It went something like this:

Original review: “I hated this book. It is a great pity it was ever published.”
Cover quote: “this book … is … great”

Ho-ho. Like that could happen.

But recently I was trying to track down the origin of a little cluster of visitors who’d come here to read my review of Greg Egan’s novel, Dichronauts. And I found that his publishers were quoting my review on the book’s Amazon pages. Under Product Description, among a number of other appreciative quotes, here’s what I’m reported to have said:

“I enjoyed this one very much . . . go and buy the book.”―The Oikofuge

Now, if you know me, or if you’ve hung around this blog for long enough, you’ll recognize that as being something I’d actually never say. Even when I do enthusiasm, I don’t do unqualified enthusiasm. So I was a bit puzzled, and I went back to check what I’d written. Here’s the full text of the section quoted; I’ve highlighted the bits that appear in the Amazon quote:

I enjoyed this one very much—in large part because the characters and problems become very engaging as the story progresses, but also because I just liked messing around with the maths. I do think Egan skipped rather lightly over some problems with the physical environment he builds—zeroes and infinities are never too far away. For instance, two objects that are aligned northeast-southwest or southeast-northwest in his world will have a separation of precisely zero, no matter how far they are separated along the north-south and east-west axes. But they will also have zero thickness measured at those 45º angles, no matter how wide they are north-south and east-west, so they shouldn’t collide—the world just seems to go a little indeterminate at those special limiting angles. And it’s not clear what actually happens to a vertical object that falls to the south or north. It gets longer as it topples, certainly, but it shouldn’t be able to get closer to the ground than a 45º tilt. Egan refers to this situation a couple of times but doesn’t get into detail. I think what he envisages happening is that the endlessly lengthening and thinning object breaks up into sections under the differential torque of gravity (like a toppling factory chimney), and then the broken sections fall vertically to the ground with minimal farther rotation.

But these tilted segments should then start to undergo their own asymptotic lengthening …

And I do think there may be a problem with this novel if you’re not a special-relativity junkie, like me. While the odd spacetime of Orthogonal was only an occasional intrusion in the narrative, which could be skimmed over, the counterintuitive spacetime distortion in Dichronauts is front-and-centre, influencing plot and the characters’ behaviour on every page. It may simply be too weird an environment for a reader who doesn’t enjoy playing with maths a little.

So the question is: when I described those exotic spacetime axes, did you perk up and want more detail? Maybe feel the need for a graph? In that case, take a look at Egan’s website, and then go and buy the book.

That’s remarkable, isn’t it? The ellipsis in the publisher’s quote conceals 350 words, four paragraphs and an illustration! In which I provided a lot of information qualifying both my enjoyment of the book and my purchase recommendation.

Cheeky is perhaps too mild a word for that elision, but we’ll go with it until I think of something better.

I’ve reported the quote to Amazon as “inaccurate product information”. I’ll let you know what happens.

Update: I got no joy from Amazon, so I contacted the publisher directly, with good results I describe in this post.