Archive for the Kids Category

a journal of the plague year [almost gone]

Posted in Books, Kids, Mountains, pictures, Travel with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , on January 23, 2021 by xi'an

Read The stars are legion, by Kameron Hurley, which I brought back from Gainesville last year. Although I cannot remember why I bought the book, it must have been a “recommendation” on Amazon… The story is part unusual, part classical, with a constant switch between the two major characters [viewpoint].  And between different times. The style is complex, maybe too complex, as the universe is slowly revealing itself, through the perception biases of the characters. Including (spoiler!) one with multiple memory erasures and two attempts at recycling. Stars are actually (spoiler!) space-ships with some possibly organic elements that are decomposing (and showing the steel skeletons), with also apparently organic smaller vessels to travel between ships or fight between clans. Some of the ship inhabitants are mutants, possibly for being unprotected from space or ship radiations (although the control and propulsion of these ships is never mentioned), possibly because they are perceived as such by different groups in the ships, à la Huxley’s Brave New World? And there seem to be only females on-board, with all of them getting (mysteriously) pregnant at one time or another, rarely giving birth to children (associated with driving the ships? creating new ships?) but rather to other organic entities, apparently contributing to keeping the ship alive. All this is quite creative, with a powerful theme of power versus motherhood, but the story-telling is just too messy for me to have enjoyed it. The more because the type of subterranean universe where characters wander from one level to the next and discover supremely different ecosystems at each level never appealed to me. Since I read Verne’s Voyage au Centre de la Terre. (And I suddenly remembered dropping out of an earlier Hurley’s book.)

Cooked (the last remaining) pumpkin risotto with (legal) Lapsang tea, which worked out rather nicely, albeit loosing most of the Lapsang flavour. Had a week of (pleasant) cookie flavour home fragrance while my wife was preparing cookies for the entire family. Cooked a brunch with my son on the last Sunday of 2020, once again with Lapsang as drink. And had a Michelin take-away with my mom in Caen, since all restaurants remain closed till an unknown date. Which proved a great choice as it was surprisingly good, once out of the (potato starch) package.

Watched Season 2 of the BBC His Dark Materials series. Still impressed by the high level of the show (and enjoying it even more as I had forgotten basically everything about The Subtle Knife!) Except for the dark matter physicist turning to I Ching to understand her empirical experiment… But it remains a great series (esp. when mostly avoiding bears.) Also rewatched a Harry Potter film with my daughter, The Order of the Phoenix, which I found rather poor on the whole, despite a few great scenes (like the Wesley twins’ departure) and the fabulous rendering of the petty bureaucratic evil of Mrs. Umbridge throughout the film. And a part of The Half Blood Prince. Which sounded much better by comparison.

“It slowly dawned on me that it’s possible for the wise men who run your life for you to see disaster coming and not have a plan for dealing with it”

Read another K.J. Parker’s book, “How to rule an empire and get away with it“, sequel to “Sixteen ways &tc.” Light (mind-candy) but enjoyable bedside reading. Somewhat of a classical trick where a double becomes the real thing, if not in a Kagemusha tragic style.

compression artifacts

Posted in Books, Kids, Travel with tags , , , , , , , on January 22, 2021 by xi'an

Kempner Fi

Posted in Books, Kids, R, Statistics with tags , , , , , , , on January 19, 2021 by xi'an

A short code-golf challenge led me to learn about the Kempner series, which is the series made of the inverted integers, excluding all those containing the digit 9. Most surprisingly this exclusion is enough to see the series converging (close to 23). The explanation for this convergence is that, citing Wikipedia,

“The number of n-digit positive integers that have no digit equal to ‘9’ is 8 × 9n−1

and since the inverses of these n-digit positive integers are less than 101−n the series is bounded by 80. In simpler terms, it converges because the fraction of remaining terms in the series is geometrically decreasing as (9/10)1−n. Unsurprisingly (?) the series is also atrociously slow to converge (for instance the first million terms sum up to 11) and there exist recurrence representations that speed up its computation.  Here is the code-golf version

n=scan()+2
while(n<-n-1){
F=F+1/T
while(grepl(9,T<-T+1))0}
F

that led me to learn about the R function grepl. (The explanation for the pun in the title is that Semper Fidelis is the motto of the corsair City of Saint-Malo or Sant-Maloù, Brittany.)

lost mathematicians of 2020

Posted in Books, Kids, Statistics, University life with tags , , , , , on January 17, 2021 by xi'an

it was the spring of hope, it was the winter of despair

Posted in Kids, Travel with tags , , , , , , , , , , , on January 16, 2021 by xi'an