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Today, Li-Xia, Andy, and I
went to "De Waarbeek". When we arrived around eleven, the parking place
was almost full. On the flyer we got it said that the park was completely
renewed and old fashioned fun. But once inside, I noticed that not much
had changed since we came here for the last time
two years ago. The only new attraction, called
Nautic Jet, was out of order. Andy did not mind this. He enjoyed
taking rides on the ducks, the marry-go-round, the train, and so on.
We went home around half past three.
In the past days, I have been investigating the Dutch power grid using
Google Earth and information sources like:
Electriciteitstransportnet TenneT TSO B.V.
(version of 2004) and
Netkaart Hoogspanningsleidingen. The cummulation of my findings
can be found in the Power grid
The Netherlands KML file, which can be opened with Google Earth.
Today, I read an article about Christian Freeling (60).
It's about 25 years ago
that I met him for the first time. He designed several abstract
games. For more information see MindSports. The article talks about his 3.5 meter long cobra
names Kobus. He is also keeping raccoon dogs. I also discovered that
he created an interesting web site about the firework disaster. He argues that Marjolein Schreurs, one of
the victims, did not desintegrate in the plast, as is the official
reading, but that her body was recovered but that her identity was
mistaken. He lived within 120 meters from the explosion and his house
Today, I came across the news about
Reversing The Signs Of Alzheimer's.
Dr Frank Gunn-Moore's team, in collaboration with researchers in
the US, have successfully reversed a sign for the progression of the
disease and prevented the death of brain cells. Some recent publication
by this team is
the article Interaction of amyloid binding alcohol dehydrogenase/AB mediates
up-regulation of peroxiredoxin II in the brains of Alzheimer's disease patients
and a transgenic Alzheimer's disease mouse model.
In the past weeks, I have been working on a program for analyzing square tilings
again. Yesterday evening, I discovered a simpler
algorithm for a certain problem while thinking about a more complex problem
This morning, I did some internet research and came across the paper
Wang Tiles for
Image and Texture Generation. It include a Wang tiling with four colours
and eight tiles that can be used to create aperiodical tilings, but also
periodical tilings. This made me think about a Rule 30 equivalent tiling
again. On Sunday, July 29, Nicolas Reimen visited me. He did his PhD research
on 2-way cellular automata. The next day, I discovered an interesting overlap
between these cellular automata and square tilings.
I discovered a simple mapping of one dimensional cellular automata
(or Elementary Cellular Automation) to square tiling and Wang tilings.
I found that each such cellular automaton can be represented by represented by
eight Wang tiles using four states (or colours). These tiles are, given
that the Wolfram Code
of the cellular automaton is written like abcdefgh, then the eight
+1+ +1+ +0+ +0+ +1+ +1+ +0+ +0+
3 3 3 2 2 1 2 0 1 3 1 2 0 1 0 0
+a+ +b+ +c+ +d+ +e+ +f+ +g+ +h+
Each horizontal line (the top and bottoms of the tiles) represents one
generation of the one dimensional cellular automaton. The states on
the right and left side, are simply the combination of the the states
on the top of the tiles on both sides.
Actually, I first discovered a mapping to square tiles. Here also
four states are needed, but sixteen tiles are needed. These are:
3-1 2-1 3-0 2-0 3-1 2-1 3-0 2-0
| | | | | | | | | | | | | | | |
1-2 1-2 1-3 1-3 0-3 0-3 0-2 0-2
1-2 1-3 0-3 0-2 1-2 1-3 0-3 0-2
| | | | | | | | | | | | | | | |
2-a 2-b 3-c 3-d 3-e 3-f 2-g 2-h
Each diagonal (from top-right till bottom-left) consisting
of 0 and 1 represents one generation.
Of course, the discoveries reported above made me think about nice collections
of jigsaw pieces. This morning, I realized that the mapping to a Wang tiling
is in fact equivalent with the jigsaw pieces that I had constructed for
Rule 30 before.
This evening, I went to Rudi's place to play Go. I was the
first to arrive. Taco and Araldo arrived a little later. Rudi told us about his
holiday to Villach where he joined the 51st
European Go Congress for two weeks. It was very hot and he felt that
because of this he did not play very well.
I played against Araldo with six stones ahead. I lost with about twenty
points. As usual I made some strong move, but also some stuppid moves.
Several times, Rudi, who was playing against Taco besides us, made some
remarks about my moves.
Forbidding the Qur'an
Today, the newspaper De Volkskrant published
the article "Enough is enough: forbid the Qur'an by
Geert Wilders of
the Partij voor de vrijheid (the political
party for freedom). Last weekend, Ehsan Jami, a 22 year old ex-muslim, was
beaten to bleeding by three muslim men, probably because he made certain remarks
about Mohammed and some passages of the Qur'an. Ehsan Jami is organize an
organisation for ex-muslims. Last weekend it was the third time he was attacked
by muslims and he is now given body guards to protect him. Geert Wilders
argues that the Qur'an is fascistish and similar to "Mein Kampf" by
Adolf Hitler and should become a forbidden book. (Today, I discovered that
"Mein Kampf" became
a bestseller in Turkey.) This article caused many reactions. There are
even people who want to prosecute Geert Wilders for these statements. Even
the government made some clear statements. However, it is clear that there
are muslims who practice the calls for violence against non-muslims as found
in the Qur'an. I too think that it would not be wise to forbid the Qur'an.
But I do think that our government should speak very loudly about anybody
bring to pratice the voilent statements in the Qur'an. It seems that our
government remained silent when Ehsan Jami was attacked. It seems that even
his fellow party members of the Labour Party did not support him. (There
are many muslims in the Labour Party and they get many votes from muslims,
because there are many muslims among the low payed labours.)
Today, the Embassy of The
Islamic Republic of Iran - The Hague condemd the statements made by
Geert Wilders, stating that Dutch society should oppose forces that divide
society and that the world on this moment needs people who call for a dialog
and understanding. How dare they make such statements, when people in their
own country are prosecuted for their believes.
According to pinknews.co.uk: "More than 140 people have been executed in Iran so far
this year, many of them convicted of 'hooliganism,' which some reports say
includes consensual gay sex."
Ehsan Jami received several death threats this morning. This was after
the muslim website contained his address and telephone number became
According to The Telegraph,
China threatens to trigger US dollar crash. In the past decade the
United States has substanial harmed it financial position by the trade
imbalance with China. It seems as if the Unites States have remained
wealthy due to money that other countries have invested in it economy.
Now they have to pay the price for this wealth. It also seems that China
is becoming an economical power that no longer can be ignored and that
it soon might take over the United States leading role in the world.
Yesterday evening, I was shocked to learn that Muslims convicted for
terror related crimes (often only preparing for terrorist activities)
are treated in a very strict manner in two detention centers in Vucht
(for men) and Rotterdam (for women). I learned this through
the television program Reporter (Dutch). This program was first
broadcasted on April 29, 2007. Although the Minister of Justice claims
that the law has not been violated, I still find like the convicts are
receiving a double punishment of their crimes, in the sense that their
treatment in prison is an additional punishment on top of the punishment
given by the judge. Several experts have pointed out that placing all
terror related convicts in a single unit, probably is not the most
effective means for treating extremist elements in our society. This
was done for the fear that these convicts could spread their radical
ideas among fellow convicts.
This morning, one of my colleagues came to tell us that he and his
girlfriend were shown on the Dutch newssite Nu.nl.
He then pointed out the image shown above here, declaring that he
was the man with the red cap and that his girlfriend was the short
girl standing on the ship. The picture was taken when he said goodbey
When Li-Xia went outside this morning, she remarked that it was cold. I decided to check for the temperature according to the
KNMI, and discovered
that we were in the coldest part of the country with a temperature
of 9.2 degrees Celsius.
Today, Annabel came home after she
had been away for more than five weeks staying with family.
Before I arrived at home she went to play with her friend Kelly
and she only came back shortly before we were going to leave
for the University to play Go. Kelly
also came with us. We were the first to arrive and I asked
Annabel for a game. I took some time before the others arrived.
I played against Taco and Annabel played with Kelly. After some
games of Go, they played checkers on the squares. I played
against Taco with eight stones ahead. From the middle game I
was convinced that I was going to lose. After I made some big
mistake in the end-game, I resigned. Taco said that my position
was not so weak as I thought. I did not count, but he guessed
that I was less than 20 points behind. We then spend some
time analyzing the game. He showed me, how I could have killed
one of his groups.
In the past weeks I developed a program for analyzing which set of tiles can tile an infinite
grid of squares, where the set of tiles is a subset of all tiles with
zeros and ones on the corners. The results are as follows:
- 60480 sets are not minimal in the sense that they are equivalent
with another set that has been dealt with earlier.
- 2284 sets have pieces that are unused by just looking at a line
- 656 sets have pieces that are unused in all possible 2x2 combinations.
- 65 sets have pieces that are unused in all possible 3x3 combinations.
- 18 sets can be partitions in subsets that can only occur in isolation.
- 12 sets can be divide in overlapping subsets that can only occur in isolation.
- For 1565 sets a cyclic rectangle has been found.
- For 315 sets a cyclic pattern of lines has been found.
- 140 sets are unsolved.
Of course, I cannot exclude the possibilit that the program contains
errors and that these results are incorrect. (Indeed, later I found some bugs)
The first set of tiles for which the program cannot decided if there
is a solution for tiling the infinite grid is the set consisting of:
10 11 10 01 11 00 01 00
00 00 10 10 10 01 01 11
However, after a little puzzling I found the a solution, which
can easily we extended in all directions. It is given below, where
I have marked occurances of the seven tiles with bold. Each group of
four numbers matches one of the seven tiles. The solution is:
Or to make it a little more graphic, using '*' and ' ':
***** * *
* * *
* **** * *
* * * *
* * *** *
* * * * *
* * * ** *
* * * * *
* * * * * *
* * * * * *
Square tilings program
The program that I presented yesterday, contained
some bugs. This program does solve the set I discussed yesterday,
but some sets that were considered as solved, are no longer regarded
as such. The program now reports:
- For 323 sets a cyclic pattern of lines has been found.
- 132 sets are unsolved.
The first set of tiles for which the program cannot decided if there
is a solution for tiling the infinite grid now is the set consisting of:
10 11 10 01 00 01 00
00 00 10 10 01 01 11
I cannot easily find a solution for this set.
This evening, Annabel and I went to
the University to play Go. When we arrived
only Marcel was waiting there. He for a moment had thought that
he had arrived at the wrong time or day. Shortly after we had
decided that he would play against us, Araldo arrived, and it
was decided that I would play against him. A little later Rudi
and Taco arrived. Marcel played three games against Annabel on
a 13x13 board giving three stones ahead. One of the games she
won with 39 points. I played with 8 stones ahead against Araldo,
and I lost with seven points. According to him, I lost the game
during the end game.
This months interesting links
July 2007 |