I write, therefore I am
With this variation on a famous statement by the philosopher Descartes, I would like to express that the act of writing about what happens in my life is important to me.
Apollo 11Today, it is 50 years ago that Apollo 11 was launced. It was on a Wednesday and at 14:32 local time in the Netherlands. It is possible that I saw the launch live and otherwise, I must have seen later on the day. This afternoon, I watched the launch at Apollo 11 in Real Time. Peter Struycken, Cor Blok, Rudi Fuchs, Ober A. de Vries, and A. Veen, written in Dutch and English, and published by Rijksuniversiteit Utrecht in 1971 from Aquilabooks for € 15.00. It is a collection of seven envelops, held together with metal spring file clip, of which five are filled with some writing of each of the authors. There are also some loose sheets containing the introduction. I am quite happy with it, because it is a rare item, which I saw only one time before, on Saturday, January 19, 2013 in the library of Stedelijk Museum.
De FundatiePeter Struycken invited me to join him visiting museum De Fundatie in Zwolle and Heino. He wanted to see the exhibition Charlotte van Pallandt - Art as one's purpose in life about the work and life of Charlotte van Pallandt, who was one of the first artist he met and with whom he stayed in contact for the rest of her life. He thought, I would like the exhibition Michael Triegel - Discordia concors, the first exhibition of the works of Michael Triegel in the Netherlands. It is always a pleasure to visit some place with Peter Struycken, because he opens my eyes through his unique way of looking at art and the worlds.
From the exhibition about Charlotte van Pallandt, I found the following works worth mentioning:
From the exhibition about Michael Triegel, I found the following works worth mentioning:
Other art works, that I found worth mentioning:
Royal Academy of Art FinalsI went to the Graduation 2019 exhibition at Royal Academy of Art in The Hague. I found the following graduates noteworth (in the order that I encountered them or their works):
Gerrit Rietveld Academie FinalsI went Amsterdam. Before going to the finals exhibition at the Gerrit Rietvel Academie, I first brought a short visit to bookshop Matrium. At the exhibition, I found the following things noteworthy (in the order, I encountered them):
Afterwards, I went back to bookshop Het Martyrium, where at 16:07:50, I bought the book Roekeloos written by Chrissie Hynde, translated to Dutch, and published by Nijgh & Van Ditmar in 2015 translated from Reckless. my life as a pretender written in English, ISBN:9789038801407, for € 8.00. I also discovered that De Slegte opened a shop again. I wnet in to have a look. At last I visited bookshop Scheltema, but did not buy any books.
-1.6°CLast night between 3 and 5 o'clock, the temperature dropped to -1.6°C at Airport Twente weather station at ground level (10cm above ground). Which is rather unusual for this time of the year, but must be due to clear sky and that the weather station is in open fields. It is the only place in the Netherlands where the temperature dropped that low. the exhibition Lost Energy at Tetem art space. The exhibition is about the energy transition. Reinier Kranendonk started with a project about energy addiction. Françoise Braun and Casper Teijgeler asked people about things they bought but not really need. This exhibition will also travel to other locations. The third work in the exhibition is by Elise Leusink. The build an installation to show how much energy it cost to make a small piece of plastic. There will also a video made by students from the University of Twente with some research they did. Anabella Meijer is a comedian and wrote about energy transition: First Help with Climate Chnage. She calls herself a visual consultant, meaning that the makes drawings. She is also climate activist. She discovered that climate change is often talked about in negative terms and not in positive terms. She states that what makes us really happy also is good for the climate.
Difficulty versus number of solutionsI decided to investigate the relationship between the difficulty versus the number of solutions of the set of Fractal Jigsaw puzzles that Annabel has made. The difficulty is determined by the average number of steps to solve a puzzle using an optimal strategy, where a step is either the placement or removal of a piece (more). The image on the right shows the result using a linear scale. From left-to-right is the difficulty and from top-to-bottom the number of solutions. As expected there are not many puzzles that have both a high number of solutions and that are very difficult. This image is a little skewed because there are far more puzzles with fewer solutions than with many solutions and similar, many more that are easy than difficult. To compensate for this, I created a table where the puzzles are divided (for both dimension) into ten groups with respect to increasing number of solutions and increasing difficulty. This resulted in the following table, which is rather uniform, except for the numbers in the bottom right corner (as expected). The table also contains the size of groups.
| 27 36 46 56 67 80 101 137 198 903 | 253 243 260 247 261 244 262 251 254 253 ----------+---------------------------------------- 1 397 | 42 32 29 31 33 27 43 46 46 68 2 272 | 28 15 20 23 20 22 22 35 47 40 3 197 | 22 15 18 18 11 17 20 30 22 24 4 163 | 13 14 14 17 20 21 10 13 19 22 6 217 | 16 23 28 15 18 22 24 22 24 25 10 305 | 25 33 28 27 37 35 27 28 29 36 16 229 | 21 22 27 24 25 26 28 20 21 15 26 249 | 20 29 24 38 26 27 32 26 18 9 54 249 | 19 25 38 25 33 27 32 20 19 11 798 250 | 47 35 34 29 38 20 24 11 9 3
Mysterious signLast Friday, I took a picture of the 'mysterious' sign with the installation of Faida El-Shoura. There are seven statements starting with the word "Possibility". The first two speak for themselves. The third has text '[ ]', which in some programming languages stands for an empty list or matrix. The fourth has the first 11 digits of π, as displayed by Google when you search for 'pi'. The fifth mentions Chand Baori, Tenochtitlan, the blue planet HD 189733 b, which is rather hostile, and an expression with 1215.67Å, which seems to be taken from Lyman-alpha emitter, which are far aways galaxies, whoes distance can be determined through the redshift of a the Lyman-alpha emission line of hydrogen. The sixth mentions the silver ratio and the French translation of "Wavelength understood by touch." The seventh has the Russian translation of "electrocution from breathing." This is followed by the text "Input" followed by 3 by 3 matrix, the text "Output" followed by 1, and an endless point definition. It seems like part of a script, possible, the script that is being used to generate the sound for the installation. I am not sure what it all means.
Finals 2019: Second visitAt the end of the afternoon, I visited the exhibition for a second time. I had a short talk with Faida El-Shoura. She told me that the mysterious print on the wall has some meaning. I met Tom van Veen and bought a copy of his book Pittu, een fragment
Sunday, June 30, 2019
Warmth recordToday, at Airport Twente a new warmth record for this date was broken with 32.8°C. The previous record was 32.3°C from 1957. In many parts of Europe warmth records were broken.
Finals 2019This afternoon, I went to the AKI finals 2019 exhibition at the AKI building. I found the works of the following graduated students noteworthy (in the order I encountered them):
At 18:38, I bought the catalog Developments 18/19 edited by Johan Visser, written in Dutch and English, and published by AKI Academy of Art & Design on Friday, June 28, 2019, ISBN:9789075522402, for € 10.00.
Hardest Fractal JigsawDuring the night, I let the program run over all of the possible puzzles (with pieces up to size five) for just one second, to discover what might be the hardest Fractal Jigsaw puzzle. The running time was 1 second. Then in the morning, I ran the top ten with half a minute runing time. This resulted in:
1336 2,2,2,2,2,2,2,2,3,3,3,4,14,15 1229 2,2,2,4,4,4,9,9,12,14,15,999 1173 2,2,2,2,2,2,2,3,3,3,3,3,3,4,9,999 981 2,2,2,2,2,4,4,4,8,9,9,18,999 954 2,2,2,2,2,2,2,2,3,4,4,9,142,999 944 2,2,2,2,2,2,2,2,3,3,3,3,4,38,999 928 2,2,2,2,4,4,4,9,12,18,38,999 913 2,2,2,2,2,2,2,3,3,3,3,4,9,34 838 2,2,2,2,2,2,3,3,3,3,3,4,12,14,999 832 2,2,2,2,2,2,2,2,3,3,3,3,4,4,9
It is suprisingly, how many of these have the 999 piece, which is the smallest possible piece. In the evening, I also looked for the easiest and hardest puzzles that can be made with the pieces of the first series that Annabel made. The hardest is 2,2,2,2,2,2,3,3,3,3,3,4,12,14,999 in the above table. Some of the easiest are:
13.0 2,2,2,3,4,7,14,14,34,38,999 13.0 2,2,2,3,3,4,12,14,14,33,34 13.1 2,2,2,2,3,3,14,14,15,33,34 13.4 2,2,2,4,10,13,14,15,33,34,999 13.5 2,2,2,2,3,3,3,4,13,14,33,34 13.6 2,2,2,3,4,12,14,14,34,38,999
Exact Cover complexityWhen playing with the puzzles Annabel created, I discovered that the puzzle that I thought was the most difficult, because it had only one solutions and lots of pieces, was actually rather simple. So, this made me think about the complexity of an exact cover. Assuming that you have some strategy for solving an exact cover, you can count how many steps it takes on average to find a solution. Because with the puzzles, some pieces with the same shape can occur more than once, I decided to implement an exact N cover algorithm, where for each position (column) you can define how many 1's it should exactly contain. Each such exact N cover can be rewritten into an exact cover by adding some extra positions (columns) and vectors (rows). After having verified the exact N cover implementation, I implemented an algorithm that uses some randomness to find a solution. The strategy it uses is to find all positions with a minimal number of vectors to be selected and than at randomly select one of the vectors that is involved, taking into account that a vector could be involved with multiple minimal positions. Futhermore, I decided to both counting the placement and the removal of a vector as a step. This algorithm is called repeatedly within a fixed time interval, to find an average. For the puzzles from the first series, the results are presented below. The first column is the name of the puzzle. The second column gives the number of solutions to the puzzle. The third column gives the average number of steps needed to solve the puzzle when running the algorith for 10 minutes. The fourth column gives the pieces that make up the puzzle. The results seems to imply that there is no relation to the number of solutions to a puzzle and the difficulty.
S1P1 123 36.9 2,2,2,2,3,4,7,9,14,14,34,999 S1P2 68 68.0 2,2,2,3,4,4,7,9,12,14,34,999 S1P3 18 34.0 2,2,2,2,3,4,4,7,14,34,38 S1P4 8 35.6 2,2,2,2,3,4,13,14,15,33,34 S1P5 3 84.5 2,2,2,3,4,4,8,9,14,15,34 S1P6 1 22.5 2,2,2,2,3,3,3,3,4,4,12,14,33 S1P7 1 24.2 2,2,2,2,3,3,3,4,4,4,7,10,14 S1P8 1 28.8 2,2,2,2,2,2,3,3,3,3,3,3,4,4,5
ExhibitionsI first went to open day at 'De Zesprong', only to discover that it was offically already over. I met some people that I knew, including Femke Kloppenburg and René Völker. Next I went to XPO to see the exhibition A State of Obscurity by I-Yen Chen. She is from Taiwan. Next, I went to the opening of The Big Discovery at photo gallary Objektief with works from first year students from Cross Media from the AKI. I liked the following works:
Saturday, June 22, 2019
BookAt 17:24, I bought the book The Te of Piglet written by Benjamin Hoff in English, illustrations by E.H. Shephard, and published by Mandarin in 1993, ISBN:9780749315146, from charity shop Het Goed for € 0.95.
BookAt 17:48, I bought the book Art in the office: ING art collection, a universal language written by Consuelo Fernandez-Ruiz in Dutch, published by Waanders in 2006, ISBN:9789040083204, from charity shop Het Goed for € 1.95.
Puzzles by AnnabelIn the past months, Annabel developed a set of eight fractal jigsaw puzzles. Today, she launched her website where they can be ordered separately or combined.
Powers continuedYesterday evening, I had a look at how the expressions of the powers of (a2 + b2) are related to each other and I arrived at this figure:
1 - + 2 1 \ + - 1 2 - + - + 2 1 3 \ + - + - 1 2 3 - + - + - + 2 1 3 4 \ + - + - + - 1 2 3 4 - + - + - + - + 2 1 3 4 5 \ + - + - + - + - 1 2 3 4 5The numbers in each line, stand for the equations and the '+' and the '-' symbols stand for the variant of the Brahmagupta-Fibonacci identity that has been choosen. The '\' is used when both '+' and '-' return the same result. This happens when one of the squares is zero. If seems that twice taking the same variant, leads to the same result. Lets see if this is generally the case:
(r2 + s2)(a2 + b2) = (rb + sa)2 + (ra - sb)2
(r2 + s2)(a2 + b2) = (rb - sa)2 + (ra + sb)2
Now, it seems that the results are not the same.Sickhouse in Enschede. First Patrick Jonkman gave a presentation about the history of electronic instruments. This was followed by a live performance by Dennis van Tilburg (on SoundCloud). Nicolas from soundforce told something about the Eurorack modules he is developing. It was mostly about a DCO (digital voltage controlled oscilator). After a short break, there were some five minute jam sessions with pairs of people. The jam was hosted by Gijs van Ouwerkerk with Ingmar Kops, Gregor Beyerle, Nicolas Toussaint, and Jasper Schütz. I listened to the first jam, but left the room when it became a little too hot for my tasted. I joined the Live Hex workshop held by Ole Nieling, which was about building a simple oscilator with the CD40106BE, also known as the Hex Schmitt Trigger (with inverter) IC. I build the basic circuit with a LDR and 10nF capacitor. I went on to experiment a little and put two oscilators in series using another 10nF capacitor. There were three more performances:
-- contact -- Frans
My life as a hacker
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