# You're reading: Travels in a Mathematical World

I asked in the previous post for suggestions of iPad apps that I could use to help with my job as a university lecturer in mathematics. I asked specifically about annotating PDF files I had made using LaTeX and recording such activity. More generally, I asked what other apps might be useful to my job and for other uses I should be thinking about. People made suggestions via comments on that post, Twitter and Google+. Thanks to all who responded. Here is a summary of the recommendations I received.

New game, everyone! Work have bought me an iPad. I have so far discovered this is basically a touch screen interface through which I can write email, read Twitter and play pinball, but I’ve heard a rumour that it can do even more than that. I’d like you to suggest what else I might do with it.

### Explaining things

I have discovered, or perhaps learned how to articulate, something fundamental: I like explaining things. Allow me to explain.

### 26th July 2004–23rd July 2013

Yesterday, with my tongue certainly in cheek, I tweeted to the BBC Breaking News Twitter account that I had handed in my thesis, with a promise of a press release to follow. Taking the lead from my over-inflated sense of self importance, Christian Perfect posted this news to The Aperiodical News feed as ‘Breaking: Peter Rowlett has submitted his doctoral thesis‘.

Recently, in order to complete the submission paperwork, I went through my PhD files and stumbled upon my original enrolment confirmation. Before the brave new world of online enrolment and online fee payment, I had to go to an office and give money to receive a stamp on a piece of paper. The enrolment slip asks me to keep it safe, which apparently I did.

### #TweetMyThesis

#TweetMyThesis is the latest in a line of similar initiatives asking you to condense your thesis into 140 characters. This time it was proposed by Times Higher Education on Twitter. I’m also aware of #TweetYourThesis, #tweetyrPhD, #TweetYourPhD and numerous individual conference versions. I’m unsure whether 2010’s #BUthesis is the first, but it might be.

My title remains ‘A Partially-automated Approach to the Assessment of Mathematics in Higher Education’. My deadline is less than three weeks away.

### What colour shirt do mathematicians wear?

Readers of The Aperiodical may recall three excellent posts on the Maths of Star Trek by Jim ‘But Not As We Know It’ Grime. At the same time, Jim discussed the topic in glorious audio with Andy Holding and Will Thompson, hosts of the Science of Fiction podcast (worth listening to, but at least visit the page to see a picture of Jim nursing a tribble). As part of this, the hosts asked Jim what uniform colour mathematicians on the Enterprise would wear.

JIM: Science and medics, those are the blue shirts.

HOST: Where do mathematicians go? Scientists?

JIM: That’s right, yes, science.

HOST: You’re safe?

JIM: Yes, I am, I’m in the blue shirt category.

Jim is pleased to say that mathematicians wear blue because, as he explains, gold and red uniformed crew were much more likely to be killed during the famous five-year mission than those in blue. I’ve written in the past about maths and mathematicians being everywhere, for example when asserting that most of the Nobel prizes are for mathematics. Was Jim right about those blue-shirted mathematicians?

### On equivalent forms of the weak Goldbach conjecture

Harald Helfgott has announced a proof of the odd Goldbach conjecture (also known as the ternary or weak Goldbach conjecture). This is big news. Like a good maths newshound, Christian Perfect promptly wrote this up for The Aperiodical as “All odd integers greater than 7 are the sum of three odd primes!

Wait, though, there’s a problem. As Relinde Jurrius pointed out on Twitter, the formulation used in the paper abstract was not quite the same.

The ternary Goldbach conjecture, or three-primes problem, asserts that every odd integer $N$ greater than $5$ is the sum of three primes. The present paper proves this conjecture.

The version Christian used makes the assertion using odd primes, whereas the paper abstract only claims “the sum of three primes”. The latter version includes $7$ because $7$ can be written as the sum of three primes, but not odd ones ($7 = 3+2+2$). Certainly, you can see both statements of the weak Goldbach conjecture used (for example, here’s the $\gt 5$ version and here’s the $\gt 7$ version). Are they equivalent?