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Diary, January 2020

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Tuesday, January 7, 2020

LISP in C#

Yesterday, someone pointed me at A Lisp interpreter in C# 7. LISP is the third programming languages that I used, after Algol 60 and Fortran. C# is a programming language that I just recently started to use. A long time ago, I made some attempts to program a LISP interpreter in Fortran. Having a lot of programming experience, I thought it would be easy to implement a LISP interpreter in C#, especially, because C# is a garbage collected language itself and in some sense rather close to LISP. I also got the idea to present the implementation is a didactic presentation with comments explaining the code in step-by-step manner. I have created the LISP interpreter in C# repository for this purpose.

Wednesday, January 8, 2020

B93 Nu

I went to the exhibition B93 Nu, which was kind of a new year reception, with works from the various artists of the B93 artist collective. I was surprised by the quality of the works on display.I did like the work with the text "bobbinhood" and the words 'be' and 'somebody' in it. I also had a look at the book Saintscape by Claudio Beorchia, which was on display. I saw that the book has an ISBN, which might indicate that there is more than one copy of it. In that case, I would be interested to buy a copy.

Thursday, January 9, 2020

The Swarm

I went to the opening of the exhibition The Swarm by Anne de boer at TETEM art space. I arrived a little late and missed the start of the tour. I was not very impressed by the exhibition and the tour.

Friday, January 10, 2020

Books, sale and party

At 16:52, I bought the following two auction catalogues published by Christies from charity shop Het Goed: In the evening, I went to bookshop Broekhuis for their pre-sale evening for 'friends' of the bookshop. I took almost an hour to look around, but could not make my mind up about buying a book.

Next, I went to PlanetArt, where there was a kind of new years party for all the people who volunteerd for GOGBOT. I arrive around the time of the new moon, which was accompanied with the first, albeit penumbral, lunar eclipse of 2020, which was at maxium at 19:09:59 UTC. I forgot to look up in the sky to see if I could see the moon. I sat downstairs with some tea. Upstairs there was music. Several times, I opened the door for some guests and talked a bit with some. One of them I saw for the third time in three days. I had a good time working on RawParser. I stayed for about two hours.

Sunday, January 12, 2020

Double date

This year, there will be a lot of special dates. Today is a double date for the notation: DD-MM-YY: 12-01-20. The other special dates of this year are:

Monday, January 13, 2020


At 16:57, I bought the book Charlotte van Pallandt: gipsen en schetsen written by Charlotte van Pallandt and Gerdien Verschoor, written in Dutch and published by Hannema-De Stuers Fundatie in 2001, ISBN:9789070842420, from charity shop Het Goed for € 3.50.

Thursday, January 16, 2020


I finished reading the novel JPod by Douglas Coupland, which I started reading on November 27 after I bought it on November 14 last year. I bought the book, because it looked interesting with respect to being a kind of epistolary novel with many fragments take from online communications and pages filled with semi-random words and numbers, such as prime numbers and the digits of pi. I did like the novel. I tried to find out if people already solved the many puzzles in the book, such as which non-prime number is inserted in the sequence of prime numbers. The only solution that I found, was in the Master thesis Puzzling translation: Breaking the code by Jonna Verdel, where on page 26 it mentions that the inserted three letter word is EMF.

Friday, January 17, 2020


At 17:05, I bought the following two books from charity shop Het Goed:

Saturday, January 18, 2020

Kunstmuseum The Hague

This morning, I went to Kunstmuseum in The Hague to see the exhibition Monet: The Garden Paintings. (If I remember correctly, the previous time, I visited this museum was on March 31, 1977.) There, I saw the following works:

Next, I saw the exhibition about Jeroen Eisinga - The Social Ladder. Several of his films were shown and 'camera' from "The Most Important Moment in My Life" (1995) was on display. After this I went to Chambers of Wonder in the basement, in a certain way the most interesting part of the museum. There I saw the following works:

Next, I saw the exhibition Barbara Nanning with works by her. Followed by this, I saw the exhibition Mondrian & De Stijl. I liked the following works, where if no name is mentioned, are by Piet Mondrian:

The last exhibition that I saw was Discover the modern. I found the following works worth mentioning:

I visited the shop of the museum, but did not buy anything.

After this, I visited a number of bookshops in The Hague and Utrecht. In The Hague, I visited: Van Stockum, The American Book Center, and Paagman. In Utrecht I visited Steven Sterk and Broese. At 18:22, I bought the book Het verborgen brein written by John Bargh, translated from the English Before You Know It to Dutch by Marianne Palm, Aad Janssen, and Nicole Seegers, published by Overamstel Uitgevers in 2018, ISBN:9789048827121, from Steven Sterk for € 7.90.

Sunday, January 19, 2020

The Long Way to a Small, Angry Planet

I finished reading the novel The Long Way to a Small, Angry Planet by by Becky Chambers after I started reading it last Thursday, the day I bought the book. It is a long time ago that I read a book in a single go. Yesterday, I had a copy of the second part in my hand when at the American Book Center, but decided to first finish the book, before buying it. The book feels a little like a sitcom, because many of the chapters can be read as a separate story and the order of some of the chapters could be rearranged without hurting the story. (I guess, it would aid making a TV show based on the book.) I have admit that it touched on some interesting philosophical, psychological and social issues.

Tuesday, January 21, 2020

Volume irregular hexahedron

One way of calculating the volume of a hexahedron is to divide it into six (or five) tetrahedron for which there is a 'simple' formulea to calculate the volume. Another method consists of calculating the volume is to divide each side in two triangles and calculate the volume of the tetrahedron made of the triangle and an arbitrary point (usually the origin). This works as long as the sides are flat. But when the four points of a side do not lay in a plane, there are two ways to divide it into triangles, which result in a different volume. So, the volumne is not really defined in this case. One approximation is to take the average of the two ways. This can be done by adding half of the volume of the tetrahedron between the four corner points. If the four points are in a plane, the volume of this tetrahedron is zero. I have no idea if this approximation is the same as defining the volume when taking the curved surface between the four edges that is made out of straight lines connecting the edges at 'equivalent' distances, kind of simular to the hyperbolic paraboloid.

Saturday, January 25, 2020


Today is the first day of the year of the rat according to the Chinese calendar. The spring festival has begun. I wish everyone, and especially all people in China, a very healthy New Year in view of Wuhan coronavirus outbreak. (The genome of the Wuhan-Hu-1 virus just encodes for ten genes, producing ten different proteins. One of the ten gene takes up almost twothirds of the genome. It would not surprise me if this is the gene for the 'evil' protein, which allows the virus to enter the human cells and gets itself replicated by those cells.)

Thursday, January 30, 2020


At 18:07:02, I bought the book A Closed and Common Orbit written by Becky Chambers in English and published by Hodder & Stoughton in 2017, ISBN:9781473621473, from bookshop Broekhuis for € 12.99.

Friday, January 31, 2020

12.3° Celsius

The previous weather record for the maximum temperature at Airport Twente for this date, was 12.1°C in 1990. In the evening, between eight and nine, a temperature of 12.3°C was recorded. It would not surprise me if the lowest temperature of 9.4°C is also a record. During this time of the year, the average maximum temperature is 5.2°C. I have not seen any snow yet, not even wet snow. Some snow did fall in the North and South of the country. We also did have no serious freezing periods.

This months interesting links

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