Statistical mechanics of tetris

I'm finding that I'm becoming increasingly fascinated by shape. It seems such a simple thing yet scratch the surface only a little and the complexity comes pouring out. Take simple tiling problems; I can tile my floor with squares or regular hexagons, but not regular octagons - they'll always leave annoying gaps. From a statistical mechanics point of view those gaps are very important, little sources of entropy that you can't get rid of. In three dimensions understanding the packing of tetrahedra has proved no simple task. But that's a story for another day.

So it came as no surprise that I was very taken with Lev Gelb's talk on polyominoes at the Brno conference. Polyominoes are connected shapes on a two dimensional lattice. A monomino is a square, a domino you know. Tetrominoes are made of four squares and are exactly like the pieces from Tetris. Assuming that they're stuck in the plane (so you can't flip them over) there are 7 tetrominoes.

Tree diagrams solve everything

Just a quick one. I saw this post, When intuition and math probably look wrong, via Ben Goldacre's mini blog. The problem is set as follows:

I have two children, one of whom is a son born on a Tuesday. What is the probability that I have two boys?

Intuition tells you the answer is 1/2, mathematicians tell you it's something else. I'll leave the answer until the end of the post in case you want to run off and solve it first. It's essentially a fancier version of the Monty Hall problem.

Comment spam

I'm getting killed by comment spam at the moment. You'd really think Google would be better at stopping it but I don't want to get into that. Anyway, given I don't have as much internet access at the moment I can't mop up the spam quick enough so for a little while I'm going to have either moderation or require openid signing in. It's a shame because I really want to keep comments open.

Update: login didn't work so for now it's bloody moderation.

Update 2: Constantly catching comment spam. Wordpress has a facility to block comments with more than one hyperlink. I'm seriously looking at moving the site over.

My iPhone is an evil vindictive bastard

Yes I know you're supposed to say phone and not iPhone, but I think it's relevant here.

Being a clever smarty pants, when I landed in the Czech Republic I switched my phone to Prague time and it took care of everything. Oo, isn't it clever! No. For some bizarre reason overnight last night it decided that I couldn't possibly still be in Czech Republic and I must be back in the UK. So this morning I managed to miss the one talk I really wanted to see (Sharon Glotzers tetrahedra talk) because I was on bloody London time.

So you can keep your retina display and your megapixels, Mr Jobs - get the bloody time right! Just about ready to throw this thing at the wall. Oh, but it is so pretty...

Brno - best poster spot ever

It's 10pm and I'm writing this during a talk on modelling water. In case you didn't know water is about as far from a simple liquid as you can get. It's very interesting, although from the baffling number of water models you'd think it's been solved by now, but they do keep going. And going...

Anyway, I'll talk more about the science later, in general I had a couple of thoughts today. First, and most certainly without naming names, there is a huge gulf in standard between the good talks and the bad talks. Experience seems to be a factor, the two best talks by a long way were the invited speakers. The best talk introduced a new subject to me, which is on coarse graining, and I felt like I had a good idea how it all worked when he finished. The worst talks I lost attention within a minute.

It surprised me that people can do this for years and still be no good at it, I guess they don't care. But it's so so important that you can tell people what you're doing! Not to be negative though, the good ones were good and they really make it worth being here.

Second thought is that this poster fiasco is heading to the ridiculous. I was lucky enough to get the board at the back of the room, facing a wall two feet away! Not exactly a prime spot as you can see from the photos. At A0 I doubt they'll be able to focus on it from that distance! C'est la vie.

I'll let you know how many punters I get.

Conferences

Seems like it's been a very long time since I've posted anything. This is mostly because things have been a bit of a blur recently preparing a paper, a talk and a poster for some up coming conferences. As soon as conference season is over I'll be back on the regular posts.

The science poster is a bizarre and demoralising ritual. You know that hardly anyone will see it (at one of my conferences there will be something like 500 posters), but you daren't not do it properly just in case. So you spend days putting this thing together, £30 getting it printed, only to have hundreds of people walk straight past it. Who knows, maybe you can catch one or two people who will write down a reference.

Anyway, this is what I'm going to be standing in front of next week, I think it's quite pretty:

It occurred to me that I haven't really blogged about my own work (is it not done?) but I'll start doing so when I return. In the meantime, it's all on the poster!

On the off chance anyone is going to Brno next week then come and find me and say hello.

Using a blog as a Logbook

Last productivity post for a while I promise, then back to proper physics.

I'm trying out using a private blog (secured and unlisted etc) as a logbook. Logbooks are so important, the first time you realise you need one it's too late. My reasoning for going online goes:

1. I can access from anywhere, including emailing in posts from my phone. For example I could take a photo of a whiteboard discussion and send it to the blog so I won't forget about it.
2.  It's safely backed up on the servers of whoever's hosting it.
3. I'm more likely to actually make entries because it's easy.
4. A blog is much like a logbook anyway so it's naturally suited.

I can see some downsides but they're all pretty minor. Security could be an issue but how sensitive is the information you put in your logbook? Well mine isn't much, I don't want to accidentally broadcast my latest idea but it wouldn't cause a new climategate or anything. Besides, I think it's pretty secure.

I've chosen to use WordPress for my logbook for one simple reason. The LaTeX integration is fantastic. It's so good I'd consider moving this blog if it wasn't such a pain (for the record I otherwise like blogger). In wordpress you do this:

I will now insert an equation here, $latex E=mc^2$, inline with the text.

which would look like

although the superscripts do appear to have messed up the alignment... Otherwise it does a brilliant job at interpreting the tex and inserting the image. If you need a lot of LaTeX then there are programmes that convert between regular .tex files and the wordpress format.

There are similar things available for blogger but I think you lose your source code in a more drastic way. Anyway, I'm going to see how it goes.