
Recent Posts
Subscribe to Complex Projective 4Space
Archives
 July 2022
 June 2022
 May 2022
 January 2022
 December 2021
 September 2021
 July 2021
 June 2021
 May 2021
 February 2021
 January 2021
 December 2020
 November 2020
 October 2020
 September 2020
 August 2020
 July 2020
 June 2020
 May 2020
 June 2019
 May 2019
 March 2019
 November 2018
 September 2018
 July 2018
 June 2018
 May 2018
 April 2018
 March 2018
 February 2018
 November 2017
 October 2017
 November 2016
 May 2016
 March 2016
 February 2016
 December 2015
 September 2015
 March 2015
 February 2015
 January 2015
 December 2014
 November 2014
 October 2014
 September 2014
 August 2014
 July 2014
 June 2014
 May 2014
 April 2014
 March 2014
 February 2014
 January 2014
 December 2013
 November 2013
 October 2013
 September 2013
 August 2013
 July 2013
 June 2013
 May 2013
 April 2013
 March 2013
 February 2013
 January 2013
 December 2012
 November 2012
 October 2012
 September 2012
 August 2012
Recent Comments
 tomtom2357 on The inadequacy of SCLT
 apgoucher on The neural network of the Stockfish chess engine
 El número TREE(3) no es infinito, pero es tan grande que ni siquiera cabe en el universo  La Fragua on TREE(3) and impartial games
 El número TREE(3) no es infinito, pero es tan grande que ni siquiera cabe en el universo – Radio Región on TREE(3) and impartial games
 El número TREE(3) no es infinito, pero es tan grande que ni siquiera cabe en el universo – Radio Centro F.M. 97.1 Pcia. De Buenos Aires on TREE(3) and impartial games
Monthly Archives: December 2012
Recapping 2012
Now that the year is drawing to a close, there are a few things worth discussing. Firstly, cp4space has a total of over 20000 views and a new seasonal banner (see above)! Mathematica 9 The Treefoil has been mentioned on mathpuzzle.com. … Continue reading
Posted in Uncategorized
Leave a comment
Busy beavers
This is the third out of a series of four articles on increasingly fastgrowing functions. The first article described the Ackermann function (corresponding to ω) and the Goodstein function (corresponding to ε_0). The second article went into much more detail about a … Continue reading
Posted in Fastgrowing functions
Leave a comment
The inadequacy of SCLT
As I mentioned a few posts ago, I included the Diophantine equation x^4 + y^6 = z^10 on the Advanced Mentoring Scheme. I’m not going to spoil it here, although I have since been informed that I had previously included it … Continue reading
Posted in Uncategorized
2 Comments
Cipher 9: Christmas cryptography
Being simultaneously Christmas Day and Cipher Tuesday, I have a lot of material to get through. Isaacs Firstly, happy 370th birthday to Sir Isaac Newton, who succeeded Isaac Barrow as the Lucasian Professor of Mathematics (both from Trinity, yay!). This gives … Continue reading
Posted in Ciphers
Leave a comment
The world still exists
It transpires that the world didn’t actually end yesterday. At the very least, Descartes’ famous deduction ‘cogito ergo sum’ seems to imply that. To summarise, the Mayan calendar has finished its 13th long count cycle; equivalently, 13×20×20×18×20 days have passed since … Continue reading
Posted in Uncategorized
Leave a comment
Dissecting the disc
At the tenth Gathering for Gardner, Colin Wright proposed the following problem. It’s quite well known, and I believe it has been published elsewhere before: ‘Dissect a [unit] disk into congruent parts at least one of which avoids the center by … Continue reading
Posted in Uncategorized
Leave a comment
TREE(3) and impartial games
This article was originally supposed to be about TREE(3) and the busy beaver function. However, I realised the potential of turning TREE(3) into a twoplayer finite game, which is surprisingly fun and means that I’ve ended up leaving uncomputable functions until a later post. … Continue reading
Posted in Activities, Fastgrowing functions
33 Comments
Cipher 8: Honeycomb
The inspiration for this cipher stemmed from a conversation with James Aaronson, when we considered the prospect of a whole new category of cipher. I was initially sceptical as to whether it could actually be implemented (they’re certainly much harder … Continue reading
Posted in Ciphers
Leave a comment
Pictures of matchstick graphs
A matchstick graph is a planar graph with a plane embedding where all edges are of unit length. The name derives from the fact that they can be assembled on a flat surface out of matchsticks of equal length. Of … Continue reading
Posted in Uncategorized
Leave a comment
Fastgrowing functions
This is the first of a projected twopart series of articles about fastgrowing functions. The first part (‘fastgrowing functions’) will introduce the concept of a fastgrowing hierarchy of functions, use some notation for representing large numbers, make an IMO shortlist problem infinitely more … Continue reading
Posted in Fastgrowing functions
Leave a comment