## Archive for February, 2011

February 27, 2011

## A random foray into data visualisation

I was thinking today about the distribution of wealth in the UK.  It’s easier to understand small numbers than large ones, so it occurred to me that you could construct a fictional population of 100 people with the same wealth distribution as the UK, and then visualise that by drawing 100 circles with areas proportional to those people’s wealth.  I’d never seen that done before, so I thought I’d give it a go. It was something of a failed experiment.  This was my first attempt:

For this one I just calculated the figures (using data from HMRC, via Wikipedia) and then drew the circles in a vector art program.  Unfortunately it looks kind of ugly.

February 26, 2011

## Falling Into a Black Hole, Part 1

A little while ago I read Leonard Susskind’s book The Black Hole War (subtitle: My Battle with Stephen Hawking to make the World Safe For Quantum Mechanics).  It’s an interesting and mostly quite readable popular science book about the black hole information paradox.  Susskind thinks that information isn’t destroyed when stuff falls into a black hole, and his book is about why.

The first part of the book has some useful thought experiments about black holes, some of which I’ll take you through below.  After that it starts to talk about string theory, whereupon it becomes as utterly incomprehensible as any other book on the subject.

However, I think Susskind makes an important logical error just before he turns to string theory.  I think that if you correct this error then it leads to a much more elegant resolution of the information paradox — one that doesn’t require the use of string theory.  I won’t get as far as talking about that in this post, but I will point out the error I think Susskind makes, and show how resolving it leads to a simpler explanation of what happens when something passes an event horizon.

February 18, 2011

## Reunweaving The Rainbow

(* Warning — Some readers may find this massively pedantic *)

A while ago I did some research into rainbows. I’d been reading about Newton and his rings, and thinking about what people say about him and his opinion on the number of colours in a rainbow. In which way these “principal colours” were important to him is a little unclear (“because they pass into one another by insensible gradation” !?!!?!, link), but it seems to me that he understood the relation between the continua of pitch and hue and their (somewhat arbitrary) relation to the respective discrete scales rather well. Anyway, I thought I would have a go at asking how many colours there are in a rainbow, perhaps there would be a sensible answer… I gave up pretty quickly, because I noticed something else.