Skip to content →

neverendingbooks Posts

i’ll take rerun requests

If you write a comment-provoking post (such as that one), you’d better deal with the reactions.

As often, the bluntest comment came from the Granada-Antwerp commuter (aka “mewt” for ‘memories of a weird traveler’…)

Javier :

Concerning the participation on the math-related posts, it is true that what you write has become more readable along the years, but yet, being able to read one of your math posts and catch the idea of what is going on (which I think is a great thing to do) is one thing. Actually understanding the details is a completely different one. And possibly most people thinks that commenting around when you only got the general idea (if any) of some math topic would be rather bold.

Personally, with your 2 last posts concerning Connes-Bost systems I am interested on understanding the story in full detail, so I printed your first post, took it home, read it carefully, made all the computations on my own (not that I dont trust yours, but you never know!) and before I had finished getting a sound impression of what was going on, the second part was already online, so had to go through the same process (in top of usual duties) just to keep your rythm. If things go as usual, by the time I am ready to make any sensible comments, you’ll be already bored of the topic and have switched to something else, so it won’t make much sense commenting at all!If its comments what you’re lasting for, write short, one-idea posts, rather than long, technically detailed ones.

The good news is that my posts become slightly more understandable. But all things can be improved… so, here’s a request :

If there is this one post you’d love to understand if only you knew already the material I subconsciously assumed, tell me or leave a comment!

and I’ll try to improve on it…

Leave a Comment

Oxen of the Sun

The Oxen of the Sun (of the Problema Bovinum) is one of the most difficult chapters in Joyce’s Ulysses. Ulysses is the 1904 version of Homer’s Odyssey so the Oxen appear also in his Book XII :

And thou wilt come to the isle Thrinacia. There in great numbers feed the kine [cattle] of Helios and his goodly flocks, seven herds of kine and as many fair flocks of sheep, and fifty in each.

Homer must have suffered from an acute form of innumeracy as the minimal solution to the cattle problem gives as the total number the smallest integer greater than

$\frac{25194541}{184119152} (109931986732829734979866232821433543901088049+ $

$50549485234315033074477819735540408986340
\sqrt{4729494})^{4658} $

a number whose actual digits take up 47 pages, one of the most useless pieces of mathematical wall-paper!

Leave a Comment

censured post : bloggers’ block

Below an up-till-now hidden post, written november last year, trying to explain the long blog-silence at neverendingbooks during october-november 2007…


A couple of months ago a publisher approached me, out of the blue, to consider writing a book about mathematics for the general audience (in Dutch (?!)). Okay, I brought this on myself hinting at the possibility in this post

Recently, I’ve been playing with the idea of writing a book for the general public. Its title is still unclear to me (though an idea might be “The disposable science”, better suggestions are of course wellcome) but I’ve fixed the subtitle as “Mathematics’ puzzling fall from grace”. The book’s concept is simple : I would consider the mathematical puzzles creating an hype over the last three centuries : the 14-15 puzzle for the 19th century, Rubik’s cube for the 20th century and, of course, Sudoku for the present century.

For each puzzle, I would describe its origin, the mathematics involved and how it can be used to solve the puzzle and, finally, what the differing quality of these puzzles tells us about mathematics’ changing standing in society over the period. Needless to say, the subtitle already gives away my point of view. The final part of the book would then be more optimistic. What kind of puzzles should we promote for mathematical thinking to have a fighting chance to survive in the near future?

While I still like the idea and am considering the proposal, chances are low this book ever materializes : the blog-title says it all…

Then, about a month ago I got some incoming links from a variety of Flemish blogs. From their posts I learned that the leading Science-magazine for the low countries, Natuur, Wetenschap & Techniek (Nature, Science & Technology), featured an article on Flemish science-blogs and that this blog might be among the ones covered. It sure would explain the publisher’s sudden interest. Of course, by that time the relevant volume of NW&T was out of circulation so I had to order a backcopy to find out what was going on. Here’s the relevant section, written by their editor Erick Vermeulen (as well as an attempt to translate it)

Sliding puzzle For those who want more scientific depth (( their interpretation, not mine )), there is the English blog by Antwerp professor algebra & geometry Lieven Le Bruyn, MoonshineMath (( indicates when the article was written… )). Le Bruyn offers a number of mathematical descriptions, most of them relating to group theory and in particular the so called monster-group and monstrous moonshine. He mentions some puzzles in passing such as the well known sliding puzzle with 15 pieces sliding horizontally and vertically in a 4 by 4 matrix. Le Bruyn argues that this ’15-puzzle (( The 15-puzzle groupoid ))’ was the hype of the 19th century as was the Rubik cube for the 20th and is Sudoku for the 21st century.
Interesting is Le Bruyn’s mathematical description of the M(13)-puzzle (( Conway’s M(13)-puzzle )) developed by John Conway. It has 13 points on a circle, twelve of them carrying a numbered counter. Every point is connected via lines to all others (( a slight simplification )). Whenever a counter jumps to the empty spot, two others exchange places. Le Bruyn promises the blog-visitor new variants to come (( did I? )). We are curious.
Of course, the genuine puzzler can leave all this theory for what it is, use the Java-applet (( Egner’s M(13)-applet )) and painfully try to move the counters around the circle according to the rules of the game.

Some people crave for this kind of media-attention. On me it merely has a blocking-effect. Still, as the end of my first-semester courses comes within sight, I might try to shake it off…

Leave a Comment