Monthly Archives: June 2011

Happy Tau Day!

Posted on June 28, 2011 by Brent

Happy day! , of course, is the fundamental circle constant which represents the ratio of any circle’s circumference to its radius. (In the past people have also used the symbol “” to represent half of ; perhaps you’ve heard of … Continue reading →

Posted in famous numbers, links, video | Tagged , , | 3 Comments

The wonderful world of Mike Reilly

Posted on June 14, 2011 by Brent

The other day I received an email from Mike Reilly, who introduced himself as a professional game and puzzle inventor, and suggested that I might be interested in taking a look at a few of his web sites. I wasn’t … Continue reading →

Posted in games, links, people, puzzles | Tagged , , , , , | 2 Comments

Collatz conjecture: an apology

Posted on June 7, 2011 by Brent

In the comments on my previous post about Gerhard Opfer’s proposed proof of the Collatz conjecture, several different people expressed the opinion that my tone was rather arrogant, and I think they have a point. So: I apologize for my … Continue reading →

Posted in meta, open problems, proof | 9 Comments

The Collatz conjecture is safe (for now)

Posted on June 4, 2011 by Brent

A few days ago John Cook reported a draft paper claiming to solve the Collatz conjecture. Of course, since the Collatz conjecture is so simple to state, it constantly attracts tons of would-be solvers, and most of the purported “proofs” … Continue reading →

Posted in open problems, proof | 43 Comments