# Our Favourite Blogs

A selection of our favourite mathematical blogs

Here at Chalkdust HQ, we love reading mathematical blogs from all over the internet. Here are a few of our favourites:

At The Guardian, Alex Bellos runs both a fortnightly puzzle blog and his Adventures in Numberland blog.

This puzzle was recently posted by Alex on his puzzle blog:

### The coin and the chessboard

A coin of diameter 1 is thrown on an infinitely large chessboard with squares of side 2. What is the chance that the coin lands on a position touching both black and white?

If you want an explanation of the answer, you can find one here.

Futility Closet describes itself as “a collection of entertaining curiosities in history, literature, language, art, philosophy, and mathematics, designed to help you waste time as enjoyably as possible.” We agree wholeheartedly with this.

Recently, this mathematical observation was published on Futility Closet:

### Two Timing

The square root of 2 is 1.41421356237… Multiply this successively by 1, by 2, by 3, and so on, writing down each result without its fractional part:

Beneath this, make a list of the numbers that are missing from the first sequence:

The difference between the upper and lower numbers in these pairs is 2, 4, 6, 8…

We can also highly recommend the Futility Closet podcast, although it is often non-mathematical.

Speaking of podcasts, we cannot fail to mention the BBC’s More or Less. Broadcast on BBC Radio 4 and the BBC World Service, it provides a weekly look into the numbers in the news. Over the years, they have looked into everything: from the reliability of FIFA world rankings to calculating the height of Lower Loxley Hall in The Archers based on how long Nigel Pargetter screamed for as he fell off it.

For those of you interested in the latest developments in theoretical physics, Backreaction is an excellent blog by quantum gravity expert Sabine Hossenfelder. It can be heavy going sometimes, but there’s some really great stuff on there, for example this Q&A discusses why we might be living in a hologram. Recently there was a big media storm as Stephen Hawking announced he’d solved the famous black hole information loss paradox. She wrote a fantastic live blog from his talk, discussing what was actually being said without the media spin that usually accompanies a Hawking announcement.

Of course, our other favourite blog has to be the amazing Chalkdust blog. You have probably already heard of this one…

Matt is a PhD student at UCL, working in the fields of general relativity and cosmology.

Matthew is a postdoctoral researcher at University College London. He hasn’t had time to play Klax since the noughties, but he’s pretty sure that Coke is it!

• ### Crossnumber winners, Issue 17

Did you solve it?
• ### Crossnumber winners, Issue 16

Did you solve it?
• ### Prize crossnumber, Issue 16

Can you solve it?
• ### Cryptic crossword, Issue 16

Can you solve it?
• ### Crossnumber winners, Issue 15

Did you solve it?
• ### My favourite LaTeX package

The Chalkdust editors share some of their favourites