Tonight in mathematics

End-of-week reading

Some things on my mind:

• The Netherlands Cricket Board has announced that they will begin handing out central contracts to their players, a substantial step in the further professionalisation of the game there.
• Sarah Kendrew has a nice introductory post on gravity emerging through changes in entropy rather than being a force in its own right; the idea was introduced last month by Eric Verlinde in a fairly readable paper.
• Two items from the LRB: Michael Hoffman on Stefan Zweig and an entry from their blog on swine flu conspiracy theories.
• Julian Sanchez hosts a documentary on remix culture, which is informative and interesting, though he sounds at times the way I worry I sound when I don’t sound very good. Yglesias, who links it, suggests second-order remixing, but I disagree and suggest instead that all orders of remixing are the same.
• Anton Garrett guest-blogs at In The Dark on the topic of colour and includes some images of very pretty and imaginative art that I nevertheless decline to call abstract.

Congratulations to the New Orleans Saints on their victory in Super Bowl XLIV this evening!

Same colour illusion

Apparently I am in a somewhat frivolous mood this evening (not that Dali is ever frivolous). Via John Baez comes a wonderful optical illusion:

I assure you that the squares labelled A & B are the same colour.

No, really. This is a wonderful illusion in that, unlike some others that I won’t shame by naming (I have geometric illusions with lines and the like in mind, however), I can’t convince myself in any visual way that the squares are similar. Even this alteration, which goes some way to dispelling the trickery, can’t fully convince. I had to open the image in Pixelmator* and confirm with the eyedropper that they are, in fact, both (120, 120, 120). You should do the same.

(I have given up on GIMP for the Mac, ‘cos the X11 interface is horrendously buggy, and the most recent versions simply crash on launch. I don’t want to have to pay for Pixelmator, though; could someone suggest an alternative?)

Destino

Well, this is news. In nineteen hundred and forty-five, Salvador Dali and Walter E. Disney collaborated on an animation project based on the surrealist’s aesthetic. After a long period of dormancy, it was completed in 2003. I don’t know of any official release of the work, yet it has appeared on Youtube, and so, it appears here.

Rosalie Joy

It’s true … I’ve recently become a father. Here’s a photo that I’ve shown everyone within a 5 mile radius:

Mother and child are doing excellently. I understand that it’s much easier for me to win arguments now (See 3:42 on this clip of the wonderful Ed Byrne).

It’s good to see Berian doing more than his fair share in my absence. I’ll be back soon with a new series. In the process of preparing my talk on the fine-tuning of the universe for intelligent life, I read a few articles that I’d like to respond to. These are the kind of articles that get quoted on internet forums as the golden bullet for/against fine-tuning. Some have minor flaws, others make we want to quote my favourite letter to the editor, from David Moore of North Lambton (Sydney Morning Herald, Sept 13, 2008):

What type of third-rate reporting is going on at the Herald? Chris Henning decides to vomit onto his keyboard and call it an “opinion”.

Stay tuned.

Warming up

The start of a new week! Via D. J. Watson:

In the light

I know I’d implied I was off ’til Monday, but Peter Coles has written an important post that demands immediate and unqualified endorsement. Sketching two stills from his life as an openly gay man, Coles communicates the progress that has and has not been made in the way differences from the inherited social norms of sexuality are handled within academia and British society.

My weekend reading

Links that make the world go round:

• Sanford Schwartz in the NY Review of Books on the Belgian figurative artist Luc Tuymans;
• Anne Enwright casts a restrained but not-quite-dispassionate eye across the moral carnage surrounding Iris Robinson;
• Bernard Keane writes for Crikey on the possibility of a no-frills banking service through Australia Post;
• In case you had forgotten, Keith Windschuttle believes that the history of indigenous Australia has been fabricated by, I don’t know, Robert Manne or something; the third volume of his epic revisionism, on the topic of the Stolen Generations in particular, has just been published and Windschuttle takes to the pages of The Australian to tell us more.
• Manne and Windschuttle may deserve one another, but The Monthly >> Quadrant. Here is John Birmingham in the former regarding the existential malaise of New South Wales.
• Amanda Ripley writes in The Atlantic about a determined investigation into what makes for great teaching at the primary and secondary level.
• And for those with extra time up their sleeves, Yves Smith has plenty more to read.

Enjoy your Australian Open/Australia v. Pakistan ODI coverage. See you Monday!

- JBJ, Berkeley, CA

WMAP 7 cosmological parameter set

Your Universe ca. 2010, per the WMAP+BAO+H₀^[1] maximum likelihood parameter set:

Parameter		WMAP+BAO+H0 ML
Hubble parameter		h	0.702		H0	70.2 km/s/Mpc
Dark matter density		Ωch2	0.1120		Ωc	0.227
Baryonic matter density		Ωbh2	0.02246		Ωb	0.0455
Total matter density		Ωmh2	0.1344		Ωm	0.272
Vacuum tension[2]		ΩΛ	0.728
Amplitude of curvature perturbation at k = 0.002/Mpc		Δ2R	2.45 x 10-9
Spectral index of density perturbations		ns	0.961
Size of linear density fluctuation at 8 Mpc/h		σ8	0.807
Redshift of matter– radiation equatlity		zeq	3196
Age of the Universe		t0	13.78 Gyr

Parameters fit directly from the data are shown in a slightly different colour; all the others have been derived from the fit parameters using the usual definitions. The determination of zeq is carried out using the WMAP 7-year data on its own. The two papers in which these figures are given are:

Larson et al. (2010), arXiv:1001.4635
Komatsu et al. (2010), arXiv:1001.4538

These papers contain many other numbers: in particular, for extensions to ΛCDM cosmology, such as neutrino species, non-zero spatial curvature and dark energy that is not the cosmological constant. I expect some of the parameters mentioned there and not here—particularly the f_NLstatistics of non-Gaussianity—to gain more public attention in the next decade as observations begin to determine the properties of the cosmological inflation that occurred in the very early Universe.

A final note: I’ve written this post only because these numbers are not written on an actual webpage—they are all in pdf or postscript files. But, it also gives me a chance to congratulate the WMAP team on their ongoing achievement.

Footnotes
1. Riess, A. et al. (2009), ApJ 699 539, arXiv:0905.0695
2. Dark energy, or, as assumed here, the cosmological constant.

The pleasures of chess

Garry Kasparov this month thinks about reviewing something-or-other in the New York Review of Books, becoming happily diverted into a discussion of what makes chess truly interesting. (I draw also from some recent conversations with S. O. Killmier.)

The big point: chess is not about who can see the most moves ahead. Computers (and humans) that win by doing this are simply winning by brute force, rather than by intelligence; in the article Kasparov memorably denigrates his result against Deep Blue as ‘losing to a $10 million alarm clock.’ If one insists that the only purpose of chess is to win, then brute force seems a very successful, though by no means infallible, way to do this. I’d like to spend a little time describing just why it isn’t fool-proof; and a lot of time showing why victory in chess is less than half the point.

Imagine you are a chess computer; in fact, imagine you are a chess computer with limitless computational power. Now here is a famous chess position—find the winning move: