We’ve had a bit of a break over the holidays, but mathematical news stops for no mince pie. From new prime numbers to mathematical doodling challenges, here’s a round-up of some of the facts/stories that we’ve seen while trying not to do any work.

### Someone discovered a new Mersenne Prime

While we were all busy frantically battering our to-do lists into submission for the year end, computers were still chipping away at discovering new prime numbers, and on 21st December, the Great Internet Mersenne Prime Search announced they’d discovered the 51st Mersenne Prime.

It’s the new largest known prime number: namely $2^{82,589,933}-1$, which has 24,862,048 digits and was discovered by Florida IT professional Patrick Laroche using the GIMPS software. He wins an award of \$3,000 – and had only been running GIMPS seriously for four months on his media server. You could be next! Get priming.

### Karim Adiprasito proved the g-conjecture for spheres

The g-conjecture, a result about simplicial spheres (simplicial complexes, constructions made up of vertices/edges/faces, that are homeomorphic to spheres), was proven earlier this month. Gil Kalai’s excited blog post explains the significance of the proof, and includes links to the paper and several other previous posts on the topic. For those of us who don’t know what it is, don’t worry: Brady’s got you covered.

Amazing: Karim Adiprasito proved the g-conjecture for spheres! on Gil Kalai’s blog

### There’s 12 days left on this cool Kickstarter

It’s already more than met its target (it was fully funded within a couple of days, and is now on 1986% of its goal), but you might still be interested in this Kickstarter for super-lovely 3D moving art sculptures called **GhostKubes**. Conceived by a Swedish inventor, the product will ship in July 2019 and small kits start from about £39.

### Reddit has quietly been collating threads about maths topics

Someone kindly sent us the link to this Reddit page, on which the ‘Everything about X’ threads are all listed. Here X runs over a bunch of topics in mathematics, from Group Theory to Topological K-theory, and the threads include discussion, experts to ask questions of, and links to useful references. Groovy!

‘Everything about X’ page on Reddit

### Mathematical Doodle Year

And finally, inspired by our month of Emmy Noether-based doodles (#noethember), Marlene Knoche has proposed a whole year of mathematical doodling, with monthly themes and the hashtag #mathyear. Join in!