Archive for book review

la maison des mathématiques

Posted in Books, Kids, pictures, Statistics, University life with tags , , , , , , , , on January 14, 2017 by xi'an

ihp0When I  worked with Jean-Michel Marin at Institut Henri Poincaré the week before Xmas, there was this framed picture standing on the ground, possibly in preparation for exhibition in the Institute. I found this superposition of the lady cleaning the blackboard from its maths formulas and of the seemingly unaware mathematician both compelling visually in the sheer geometric aesthetics of the act and somewhat appalling in its message. Especially when considering the initiatives taken by IHP towards reducing the gender gap in maths. After inquiring into the issue, I found that this picture was part of a whole photograph exhibit on IHP by Vincent Moncorgé, now published into a book, La Maison des Mathématiques by Villani, Uzan, and Moncorgé. Most pictures are on-line and I found them quite appealing. Except again for the above.

Great North Road [book review]

Posted in Books, Running, Travel with tags , , , , , , , , , , , , , , , on January 6, 2017 by xi'an

As I was unsure of the Internet connections and of the more than likely delays I would face during my trip to India, I went fishing for a massive novel on Amazon and eventually ordered Peter Hamilton’s Great North Road, a 1088 pages behemoth! I fear the book qualifies as space opera, with the conventional load of planet invasions, incomprehensible and infinitely wise aliens, gateways for instantaneous space travels, and sentient biospheres. But the core of the story is very, very, Earth-bound, with a detective story taking place in a future Newcastle that is not so distant from now in many ways. (Or even from the past as the 2012 book did not forecast Brexit…) With an occurrence of the town moor where I went running a few years ago.

The book is mostly well-designed, with a plot gripping enough to keep me hooked for Indian evenings in Kolkata and most of the flight back. I actually finished it just before landing in Paris. There is no true depth in the story, though, and the science fiction part is rather lame: a very long part of the detective plot is spent on the hunt for a taxi by an army of detectives, a task one would think should be delegated to a machine-learning algorithm and solved in a nano-second or so. The themes heavily borrow from those of classics like Avatar, Speaker for the Dead, Hyperion [very much Hyperion!], Alien… And from The Girl with the Dragon Tattoo for an hardcore heroin who is perfect at anything she undertakes.  Furthermore, the Earth at the centre of this extended universe is very close to its present version, with English style taxis, pub culture, and a geopolitic structure of the World pretty much unchanged. Plus main brands identical to currents ones (Apple, BMW, &tc), to the point it sounds like sponsored links! And no clue of a major climate change despite the continued use of fuel engines. Nonetheless, an easy read when stuck in an airport or a plane seat for several hours.

Fool’s quest [book review]

Posted in Books, Kids with tags , , , , , , , on October 23, 2016 by xi'an

Although I bought this second volume in the Fitz and the Fool trilogy quite a while ago, I only came to read it very recently. And enjoyed it unreservedly! While the novel builds upon the universe Hobb created in the liveship traders trilogy (forget the second trilogy!) and the Assassin and Fool trilogies, the story is compelling enough to bring out excitement and longing for further adventures of Fitz and the Fool. Many characters that were introduced in the earlier volume suddenly take on substance and meaning, while the main characters are no longer heroes of past eras, but also acquire further depth and subtlety. Even long-lasting ones like Chade. I cannot tell whether this new dimension of the plights affecting the Six Duchies and its ruler, King Verity, was conceived from the start or came later to the author, but it really fits seamlessly and increases by several orders of magnitude the epic feeling of the creation. Although it is hard to rank this book against the very first ones, like Royal Assassin, I feel this is truly one of the best of Hobb’s books, with the right mixture of action, plotting, missed opportunities and ambiguous angles about the main characters. So many characters truly come to life in this volume that I bemoan the sluggish pace of the first one even more now. While one could see Fool’s Quest as the fourteenth book in the Realm of the Elderlings series, and hence hint at senseless exploitation of the same saga, there are just too many new threads and perspective there to maintain this posture. A wonderful book and a rarity of a middle book being so. I am clearly looking forward the third instalment!

speaker for the dead [book review]

Posted in Books, Kids, Travel with tags , , , , , , , , , , , on October 8, 2016 by xi'an

Here is another book I bought for next to nothing at Beers Book Center in Sacramento. I have read several times Ender’s Game, which I consider as a major science-fiction book, for the fantastic plot, the psychological analysis of the main character, and the deeper reflections about the nature of war and the extermination of other forms of life, even when those are extremely alien. For one reason or another, I never had the opportunity to read the sequel trilogy, which starts with Speaker for the Dead. The 37 hour trip back home from Melbourne was a perfect opportunity to catch up and I read this 1986 instalment in the plane, once I was too tired to read statistics papers on my computer screen. It is a very good (if not major) book, with a lot of threads to philosophy, ethics, ethnology, and (almost) no hard science-fi’ line in that most of the story takes place in a very limited universe, a town on a monotone planet (monotone as in mono-tone, for it enjoys no diversity in both flaura and fauna), with a prohibited access to the rest of the planet, and sentient if alien autochtones. The main plot is thus centred on uncovering the culture and specifics of those autochtones, under strict regulations (from the central planet) preventing cultural contaminations. Or aimed at preventing, as contamination does occur nonetheless. The new culture is quite fascinating in the intricate symbiosis between flaura and fauna, a theme repeated (differently) in Avatar. This progressive uncovering of what first appears as primitive, then cruel, is great. The influence of the Catholic Church is well-rendered, if hard to believe that many centuries in the future, as is the pan- and extra-humanist vision of Ender himself. The concept of Speaker for the Dead is by itself just brilliant! What I like less in the story is the very homely feeling of being in a small provincial town with gossips from everyone about everyone and a lack of broader views. Not that I particularly lean towards space operas, but this secluded atmosphere is at odds with the concept of hundreds of colonised planets by colons from Earth. In particular, assuming that each planet is colonised by people from the same place and culture (Portugal in the current case) does not sound realistic. Anyway, this is a good book and I would have read the sequel Xenocide, had I had it with me during this looong trip.

inferential models: reasoning with uncertainty [book review]

Posted in Books, Statistics, University life with tags , , , , , , , , , on October 6, 2016 by xi'an

“the field of statistics (…) is still surprisingly underdeveloped (…) the subject lacks a solid theory for reasoning with uncertainty [and] there has been very little progress on the foundations of statistical inference” (p.xvi)

A book that starts with such massive assertions is certainly hoping to attract some degree of attention from the field and likely to induce strong reactions to this dismissal of the not inconsiderable amount of research dedicated so far to statistical inference and in particular to its foundations. Or even attarcting flak for not accounting (in this introduction) for the past work of major statisticians, like Fisher, Kiefer, Lindley, Cox, Berger, Efron, Fraser and many many others…. Judging from the references and the tone of this 254 pages book, it seems like the two authors, Ryan Martin and Chuanhai Liu, truly aim at single-handedly resetting the foundations of statistics to their own tune, which sounds like a new kind of fiducial inference augmented with calibrated belief functions. Be warned that five chapters of this book are built on as many papers written by the authors in the past three years. Which makes me question, if I may, the relevance of publishing a book on a brand-new approach to statistics without further backup from a wider community.

“…it is possible to calibrate our belief probabilities for a common interpretation by intelligent minds.” (p.14)

Chapter 1 contains a description of the new perspective in Section 1.4.2, which I find useful to detail here. When given an observation x from a Normal N(θ,1) model, the authors rewrite X as θ+Z, with Z~N(0,1), as in fiducial inference, and then want to find a “meaningful prediction of Z independently of X”. This seems difficult to accept given that, once X=x is observed, Z=X-θ⁰, θ⁰ being the true value of θ, which belies the independence assumption. The next step is to replace Z~N(0,1) by a random set S(Z) containing Z and to define a belief function bel() on the parameter space Θ by

bel(A|X) = P(X-S(Z)⊆A)

which induces a pseudo-measure on Θ derived from the distribution of an independent Z, since X is already observed. When Z~N(0,1), this distribution does not depend on θ⁰ the true value of θ… The next step is to choose the belief function towards a proper frequentist coverage, in the approximate sense that the probability that bel(A|X) be more than 1-α is less than α when the [arbitrary] parameter θ is not in A. And conversely. This property (satisfied when bel(A|X) is uniform) is called validity or exact inference by the authors: in my opinion, restricted frequentist calibration would certainly sound more adequate.

“When there is no prior information available, [the philosophical justifications for Bayesian analysis] are less than fully convincing.” (p.30)

“Is it logical that an improper “ignorance” prior turns into a proper “non-ignorance” prior when combined with some incomplete information on the whereabouts of θ?” (p.44)

Continue reading

The one-hundred year old man who climbed out of the window and disappeared [book review]

Posted in Books with tags , , , , , , , , on September 11, 2016 by xi'an

Scandinavian picaresque, in the spirit of the novels of Paasilinna, and following another book by Jonas Jonasson already commented on the ‘Og, The Girl who saved the King of Sweden, but not as funny, because of the heavy recourse to World history, the main (100 year old) character meeting a large collection of major historical figures. And crossing the Himalayas when escaping from a Russian Gulag, which reminded me of this fantastic if possibly apocryphal The Long Walk where a group of Polish prisoners was making it through the Gobi desert to reach India and freedom (or death). The story here is funny but not that funny and once it is over, there is not much to say about it, which is why I left it on a bookshare table in Monash. The current events are somewhat dull, in opposition to the 100 year life of Allan, and the police enquiry a tad too predictable. Plus the themes are somewhat comparable to The Girl who …, with atom bombs, cold war, brothers hating one another…

Darwin’s radio [book review]

Posted in Books, Kids, pictures, University life with tags , , , , , , , , , , , , , , , , on September 10, 2016 by xi'an

When in Sacramento two weeks ago I came across the Beers Books Center bookstore, with a large collection of used and (nearly) new cheap books and among other books I bought Greg Bear’s Darwin Radio. I had (rather) enjoyed another book of his’, Hull Zero Three, not to mention one of his first books, Blood Music, I read in the mid 1980’s, and the premises of this novel sounded promising, not mentioning the Nebula award. The theme is of a major biological threat, apparently due to a new virus, and of the scientific unraveling of what the threat really means. (Spoilers alert!) In that respect it sounds rather similar to the (great) Crichton‘s The Andromeda Strain, which is actually mentioned by some characters in this book. As is Ebola, as a sort of contrapoint (since Ebola is a deadly virus, although the epidemic in Western Africa now seems to have vanished). The biological concept exploited here is dormant DNA in non-coding parts of the genome that periodically get awaken and induce massive steps in the evolution. So massive that carriers of those mutations are killed by locals. Until the day it happens in an all-connected World and the mutation can no longer be stopped. The concept is compelling if not completely convincing of course, while the outcome of a new human race, which is to Homo Sapiens what Homo Sapiens was to Neanderthal, is rather disappointing. (How could it be otherwise?!) But I did appreciate the postulate of a massive and immediate change in the genome, even though the details were disputable and the dismissal of Dawkins‘ perspective poorly defended. From a stylistic perspective, the style is at time heavy, while there are too many chance occurrences, like the main character happening to be in Georgia for a business deal (spoilers, spoilers!) at the times of the opening of collective graves, or the second main character coming upon a couple of Neanderthal mummies with a Sapiens baby, or yet this pair of main characters falling in love and delivering a live mutant baby-girl. But I enjoyed reading it between San Francisco and Melbourne, with a few hours of lost sleep and work. It is a page turner, no doubt! I also like the political undercurrents, from riots to emergency measures, to an effective dictatorship controlling pregnancies and detaining newborns and their mothers.

One important thread in the book deals with anthropology digs getting against Native claims to corpses and general opposition to such digs. This reminded me of a very recent article in Nature where a local Indian tribe had claimed rights to several thousand year old skeletons, whose DNA was then showed to be more related with far away groups than the claimants. But where the tribe was still granted the last word, in a rather worrying jurisprudence.