Tuesday, 27 November 2012

A Roguelike Overview

When I started this blog, I had several things I wanted to discuss.  Things like atheism, feminism and particle physics are fairly serious subjects, and writing about them demands time.  So I threw roguelikes in as a more light-hearted subject, figuring that I could write posts about them when I wanted something quick and easy.

Well, that's not how it turned out.

Monday, 26 November 2012

Climate Change Consensus

Via Pharyngula, a post on the scientific consensus in Climate Change from DeSmogBlog:
By my definition, 24 of the 13,950 articles, 0.17% or 1 in 581, clearly reject global warming or endorse a cause other than CO2 emissions for observed warming. The list of articles that reject global warming is here. The 24 articles have been cited a total of 113 times over the nearly 21-year period, for an average of close to 5 citations each. That compares to an average of about 19 citations for articles answering to "global warming," for example. Four of the rejecting articles have never been cited; four have citations in the double-digits. The most-cited has 17.
The study period ran from 1991 to this year.

The Right Thing for Bad Reasons

A story the BBC classifies as Technology, but I prefer Scary as Shit:
A court challenge has delayed plans to expel a Texan student for refusing to wear a radio tag that tracked her movements.
Religious reasons led Andrea Hernandez to stop wearing the tag that revealed where she was on her school campus.
The tags were introduced to track students and help tighten control of school funding.
Ms Hernandez refused to wear the tag because it conflicted with her religious beliefs, according to court papers. Wearing such a barcoded tag can be seen as a mark of the beast as described in Revelation 13 in the Bible, Ms Hernandez's father told Wired magazine in an interview.
So.  Where to begin?

Monday, 19 November 2012

Concern Trolling

I see that the Church of England is to vote on whether to allow women bishops.  Usually in cases like this, my desire for a religious organisation to do the ultimately self-destructive thing is tempered by the realisation that this will cause real, serious harm to members of that religion.  But here the harm is minor, so I encourage the church to stick to its tradition, vote no, and speed its path to irrelevance.

Tuesday, 13 November 2012


There's yet another new observation that agrees perfectly with the Standard Model and shows no sign of new physics.  To quote one of my friends, "this game isn't fun any more".

The process in question is the decay of a bound state of a bottom and strange quarks to two muons.  This decay is heavily suppressed in the Standard Model, happening only three times in a billion events.  The tiny Standard Model rate made it an excellent place to look for contributions from new particles and interactions.  A much higher or lower rate than expected would have been an exciting discovery.

Instead, the results agree well with the Standard Model prediction.  Technically, this is evidence rather than a true discovery (3 sigma instead of 5), but at this point it's unlikely that we'll see anything radically different.  And we have one more piece of evidence pointing towards the Standard Model and nothing else.

Monday, 12 November 2012

An Odd Political Feeling

So, I was reading in the Guardian online about the issue of boundary reform.  This is the Conservative party's desire to reduce the overall number of MPs and change how they are divvied up.  However, they are facing a revolt (or at least resistance) from their nominal coalitian partners, the Lib Dems:
The Conservatives are in talks with the Democratic Unionist party (DUP)to win their backing for moves to cut the number of MPs at Westminster, Tory sources have told the Guardian.
The party is also looking to win the support of one of the nationalist parties in a bid to keep alive constituency boundary reforms that would improve Tory chances of securing an overall majority at the 2015 election. Prime minister David Cameron fears Labour and Liberal Democrats will combine to defer the boundary reforms until after the election.
The DUP, for reference, are one of the Northern Irish parties.

Usually, I'd enjoy at least a little Schadenfreude at the failings of a right wing party.  That's double in a case like this, which could easily be called gerrymandering (second comment below the article!)  But instead I feel somewhat conflicted.

Saturday, 10 November 2012

Bayes vs Frequentist

I hate to link to XKCD for the second comic in a row, but the most recent one really struck a chord with me.  While it is a little unfair, it hits what is to me the essential weakness of frequentist statistics: that the standard null-hypothesis rejection only considers how unlikely something is to happen by chance.  In contrast, the Bayesian analysis weighs the different possibilities using prior information.

Also, the willingness of the Bayesian character in the strip to place a bet relates to the characterisation of probability as degrees of belief; intuitive, meaningful in a Bayesian approach, but impossible under a strict frequentist interpretation.

Friday, 9 November 2012

What is Seen

So, a couple of days ago I discussed the problem of infinities in quantum field theories (QFTs).  I noted that two types of infinities exist, infrared (where we get a 1/0 in our perturbation expansion) and ultraviolet (where an integral to infinity diverges).  Today I'll discuss the resolution to the former, which is conceptually easier to grasp.  What makes this question interesting is that the answer forces us to think about what we can actually hope to measure in an experiment.

Wednesday, 7 November 2012

No Surprises

So apparently there was an election today?

As so often, Randall Munroe of XKCD gets to the point:
Props to Nate Silver, Sam Wang and especially Drew Linzer, who's been predicting this outcome since June.  Scorn to the media pundits and conservative bloggers who attacked Nate Silver for the temerity to suggest Obama was ahead on the basis that the polls showed Obama was ahead.  Relief for me, that my USAlien friends can live in a country that is still at least partly sane.

Tuesday, 6 November 2012

Juggling Infinities

In the introduction to his textbook on quantum field theory, Steven Weinberg recounts a saying from his days as a (post-)graduate student:
Just because something is infinite does not mean it is zero!
The infinities here show up in quantum field theory (QFT) when we look at the perturbation series beyond leading order.  They confused people a lot during the development of QFT, but their resolution is physically interesting, and something I've been meaning to talk about for a while.  Today, I'm only going to be able to set up the problem; I hope to get to the solution by the end of the week.

Monday, 5 November 2012

Taxes are Optional

Another day, another story of massive tax avoidance:
Apple paid less than 2% corporation tax on its profits outside the US, its filing with US regulators has shown.
The company paid $713m (£445m) in the year to 29 September on foreign pre-tax profits of $36.8bn, a rate of 1.9%.
 The key line comes later in the report, though:
It has not been suggested that any of their tax avoidance schemes are illegal.
It's okay, though.  It's not as if countries around the world are in some sort of budget crisis, or anything.