# Vi Hart is crowdfunding

If you appreciate the work of internet mathematician and hyperbolic virtual reality pioneer Vi Hart, or even if you’ve never heard of her before, you can now help support her work by subscribing to her Patreon. Vi Hart has never put any adverts on her videos or charged for her work until now, but since she’s stopped being employed by people who support that, she’s in need of your help. Check out the video below for details, or click the link below that to add your support.

Vi Hart’s Patreon page

# HLF Blogs: Is mathematics idealistic or realistic?

In September, Katie and Paul spent a week blogging from the Heidelberg Laureate Forum – a week-long maths conference where current young researchers in maths and computer science can meet and hear talks by top-level prize-winning researchers. For more information about the HLF, visit the Heidelberg Laureate Forum website.

5th Heidelberg Laureate Forum 2017, Heidelberg, Germany, Picture/Credit: Christian Flemming/HLF

The closing talk of the HLF’s main lecture programme (before the young researchers and laureates head off to participate in scientific interaction with SAP representatives to discuss maths and computer science in industry) was given by Fields Medalist Steve Smale.

# Ditching the fifth axiom (video)

Watch geometer/topologist Caleb Ashley explain the parallel postulate on Numberphile.

# “Pariah Moonshine” Part I: The Happy Family and the Pariah Groups

Being a mathematician, I often get asked if I’m good at calculating tips. I’m not. In fact, mathematicians study lots of other things besides numbers. As most people know, if they stop to think about it, one of the other things mathematicians study is shapes. Some of us are especially interested in the symmetries of those shapes, and a few of us are interested in both numbers and symmetries.

# Footballs on road signs: an international overview

I’m an old fashioned manager, I write the team down on the back of a fag packet and I play a simple 4-4-2.

• Mike Bassett, England Manager

I’m very much like Mike Bassett: I like standing on the terraces, I like full-backs whose main skill is kicking wingers into the ad hoardings, and – most of all – I like geometrically correct footballs.

# @standupmaths’ petition has had a response from the government

Friend of the site Matt Parker recently made headlines because of his UK Government Petition to correct the heinous geometrical oddity that is the UK Tourist sign for a football ground. In the standard sign, somehow a sheet of tessellating hexagons is depicted as wrapping around a sphere in a highly improbable (and provably impossible) way.

The petition has achieved a modicum of success, in that it’s passed the 10,000 signatures required to elicit a response from the government. Sadly, the response isn’t quite what you’d like to hear.

# Stirling’s numbers in a nutshell

This is a guest post by researcher Audace Dossou-Olory of Stellenbosch University, South Africa.

In assignment problems, one wants to find an optimal and efficient way to assign objects of a given set to objects of another given set. An assignment can be regarded as a bijective map $\pi$ between two finite sets $E$ and $F$ of $n\geq 1$ elements. By identifying the sets $E$ and $F$ with $\{1,2,\ldots, n\}$, we can represent an assignment by a permutation.