Puzzlebomb is a monthly puzzle compendium. Issue 39 of Puzzlebomb, for March 2015, can be found here: Puzzlebomb – Issue 39 – March 2015 The solutions to Issue 39 can be found here: Puzzlebomb – Issue 39 – March 2015 – Solutions Previous issues of Puzzlebomb, and their solutions, can be found here.
Wolfram|Alpha can’t. But CP can!

Christian Perfect has turned into a one-man plug for the holes in Wolfram|Alpha.
Each pair of smartphones has exactly one Dobble app in common

Card game fans might be familiar with the game of Dobble, in which a set of cards featuring symbols is laid out on the table, and family members tear each other’s hands off/eyes out in order to find the one symbol a given pair of cards has in common. Well, it’s now also available virtually!
From the Mailbag: Golfing Combinatorics

A reader’s Dad is in a combinatoric golf conundrum! Katie Steckles tries to help, with maths.
The Topological Tverberg Conjecture is False
Attention, Topological Combinatorialists! The topological Tverberg Conjecture, described as ‘a holy grail of topological combinatorics’, is false. The conjecture says that any continuous map of a simplex of dimension $(r−1)(d+1)$ to $\mathbb{R}^d$ maps points from $r$ disjoint faces of the simplex to the same point in $\mathbb{R}^d$. In certain cases the conjecture has been proven true,…
Apiological: mathematical speculations about bees (Part 2: Estimating nest volumes)
This is part 2 of a three-part series of mathematical speculations about bees. Part 1 looked at honeycomb geometry. Honeybees scout for nesting sites in tree cavities and other nooks and crannies, and need to know whether a chamber is large enough to contain all the honey necessary to feed their colony throughout the winter. A volume of less…
Manchester MathsJam recap, January 2015

Manchester’s first MathsJam of 2015 (and indeed, all the other first MathsJams of 2015 in cities all over the world) met on 20th January, rousing us all from a Christmas-induced slumber and gently easing us back into a year of recreational maths. Here’s a round-up of what we did.