Archive for China

30 years later… [30年后]

Posted in pictures with tags , , , , , , , , , on June 4, 2019 by xi'an

Nature tea[dbits]

Posted in Books, pictures, University life, Wines with tags , , , , , , , , , , , , , , , , on February 28, 2019 by xi'an

A very special issue of Nature (7 February 2019, vol. 556, no. 7742). With an outlook section on tea, plus a few research papers (and ads) on my principal beverage. News about the REF, Elsevier’s and Huawei’s woes with the University of California, the dangerous weakening of Title IX by the Trump administration, and a long report on the statistical analysis of Hurricane Maria deaths, involving mostly epidemiologists, but also Patrick Ball who took part in our Bayes for Good workshop at CIRM. Plus China’s food crisis and ways to reduce cropland losses and food waste. Concerning the tea part(y), a philogenetic study of different samples led to the theory that tea was domesticated thrice, twice in Yunnan (China) and once in Assam (India), with a divergence estimated at more than twenty thousand years ago. Another article on Pu-Ehr, with the potential impacts of climate change on this very unique tea. With a further remark that higher altitudes increase the anti-oxydant level of tea… And a fascinating description of agro-forestry where tea and vegetables are grown in a forest that regulates sun exposure, moisture evaporation, and soil nutrients.

ISBA World meetings to come

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , on January 27, 2019 by xi'an

June 2020: Kumming, Yunnan, China

June 2022: Montréal, Québec, Canada

June 2024: Venezia, Veneto, Italy

travel photograph of the year

Posted in Mountains, pictures, Travel with tags , , , , , , , on December 31, 2018 by xi'an

spotlight on Xi’an!

Posted in pictures with tags , , , , on November 24, 2018 by xi'an

the three-body problem [book review]

Posted in Books with tags , , , , , , , on February 5, 2017 by xi'an

“Back then, I thought of one thing: Have you heard of the Monte Carlo method? Ah, it’s a computer algorithm often used for calculating the area of irregular shapes. Specifically, the software puts the figure of interest in a figure of known area, such as a circle, and randomly strikes it with many tiny balls, never targeting the same spot twice. After a large number of balls, the proportion of balls that fall within the irregular shape compared to the total number of balls used to hit the circle will yield the area of the shape. Of course, the smaller the balls used, the more accurate the result.

Although the method is simple, it shows how, mathematically, random brute force can overcome precise logic. It’s a numerical approach that uses quantity to derive quality. This is my strategy for solving the three-body problem. I study the system moment by moment. At each moment, the spheres’ motion vectors can combine in infinite ways. I treat each combination like a life form. The key is to set up some rules: which combinations of motion vectors are “healthy” and “beneficial,” and which combinations are “detrimental” and “harmful.” The former receive a survival advantage while the latter are disfavored. The computation proceeds by eliminating the disadvantaged and preserving the advantaged. The final combination that survives is the correct prediction for the system’s next configuration, the next moment in time.”

While I had read rather negative reviews of the Three-Body Problem, I still decided to buy the book from an Oxford bookstore and give it a try. Ìf only because this was Chinese science-fiction and I had never read any Chinese science-fiction. (Of course the same motivation would apply for most other countries!) While the historical (or pseudo-historical) part of the novel is most interesting, about the daughter of a university physicist killed by Red Guards during the Cultural Revolution and hence forever suspect, even after decades of exile, the science-fiction part about contacting another inhabited planet and embracing its alien values based on its sole existence is quite deficient and/or very old-fashioned. As is [old-fashioned] the call to more than three dimensions to manage anything, from space travel to instantaneous transfer of information, to ultimate weapons. And an alien civilization that is not dramatically alien. As for the three body problem itself, there is very little of interest in the book and the above quote on using Monte Carlo to “solve” the three-body problem is not of any novelty since it started in the early 1940’s.

I am thus very much surprised at the book getting a Hugo award. For a style that is more reminiscent of early Weird Tales than of current science-fiction… In addition, the characters are rather flat and often act in unnatural ways. (Some critics blame the translation, but I think it gets deeper than that.)

Pu Erh [普洱茶]

Posted in pictures, Travel with tags , , , , on October 1, 2016 by xi'an

Two massive pancakes of Pu Erh (Pǔ’ěr) [fermented] tea my student Changye brought me back from Yunnan (made by the factory that revolutionised the making of Pu Erh) and that I am looking forward tasting!