Exactly four years have gone since I wrote my first post in this blog, 2016-01-09. It was really short, talking about potatoes, but it gave me the kick to want more. The story about why I started the blog was published on 2017-01-14.
Thank you all who follow my blog and write me with suggestions about what to publish in future posts!
A hint to ‘Can you use an hourglass’?
In my most recent post, on 2019-12-31 , I gave you a problem involving the use of two different hourglasses, with capacity of 11 min and 7 min, respectively, and asked you to measure exactly 15 min.
If you are still fighting with the solution, let me give you two important hints:
11 – 7 = 4
15 – 11 = 4
Can you solve it now?
A complete solution will be presented in my next post.
Once again, it is that day of the year when we reflect over how the year behind us was and make our predictions and wishes for the year to come.
One important piece of news during 2019 was that researchers at my alma mater Chalmers University of Technology, Gothenburg, Sweden, led by professor Kasper Moth-Poulsen reported that they have developed a molecule, that is able to capture the sun’s rays, store it as chemical energy for up to 18 years, and retrieve the energy and convert it into heat when needed.
The following graphic shows how it all works:
References # 1 through 4 below contain more material if you are interested in further details.
Can you use an hourglass?
So you think are smart? Then show it now! We have two hourglasses like the ones shown above. The bigger ones completes one cycle in 11 minutes, the small one in 7 minutes.
Question: Using a combination of these two hourglasses, you need to measure a time lapse of exactly 15 minutes. How would you do it? (Solution to follow in the first blog post of 2020.)
I wish all my faithful blog readers a HAPPY NEW YEAR!
As you probably already have heard, today exactly 30 years has gone since the government of East Germany was pressed to permit its citizens in East Berlin to visit West Berlin, which eventually led to the extinction of the whole East Germany and its reunification in 1991 with West Germany.
The first time I visited Berlin was in May 1970, when the Wall, which divided the city into two parts, was going on its 9th year. My German language class went on a field trip for almost a week. First, we took the train to the South of Sweden, where the train boarded a ferry to Sassnitz in East Germany. After four hours on the boat, it arrived on German shores and from there it was no longer an electric locomotive pushing the train, but an old steam engine with its heavy black smoke, paving its way through the grey landscape, all the way to West Berlin. See also reference #1 below.
Unfortunately, I do not have any photos left from the trip to show, but I remember well the contrast between the two parts of Berlin. We stayed at a hotel in modern West Berlin, close to the business street Kurfürstendamm and had quite a few interesting and funny days there. On 1970-05-08 was the 25th anniversary of the end of World War II, which of course created some heavy demonstrations, and on the following day we went to Berlin’s Olympic Stadium to see the West German football team beat Ireland with 2-1.
But the strongest memory of the whole week was no doubt from the visit we paid on 1970-05-07 to East Berlin. We took the S-Bahn and after quite some waiting in the checkpoint, we were “free” to walk around in East Berlin. I remember the visit to the Pergamon museum with its majestic Pergamon altar and other impressive artefacts. But the most vivid memory comes from the film of the trip that my friend Jan Johansson and I had been commissioned to create. He was the Super-8 camera man, whereas I made the sound recordings on the brand new cassette tape recorder and interviewed people on the street about how life was in East Berlin for everyday people, a dangerous task. Only later would our teachers learn about that and reprimand us.
My second visit to Berlin only occurred in October 2006, when I was there for a brief business meeting, but I also returned in June 2007, when I had a whole day to go on a guided walk through the streets of Berlin. It was extremely interesting and our guide, who was a native Berliner, had extensive answers to all of our questions. No wonder that the originally planned 4 hour walk only ended after 6 hours!
Below are some photos I took on that city walk on 2007-06-09.
Photos taken in chronological order during the city walk:
Photo #1: Fernsehturm (TV tower) at Alexanderplatz. Since most people in East Berlin could watch TV broadcasts from the West, although it was forbidden, the East German government decided to build an enigmatic TV tower that would be seen all over both parts of Berlin. There is a rumour that the Swedish engineering firm that made the design on purpose made it so that when the sun shines on it from a certain angle, a golden cross appears on the globe. The Berliners call it the Pope’s revenge, since East Germany was so hard on religion.
Photo #2: In central Berlin there is an island named Museum Island, where many interesting museums are located. I already mentioned the Pergamon museum in 1970, but of course there are many more. This a photo taken from the steps of Altes Museum (Old museum), home to antiquities. To the left is the catholic Berliner Dom (Berlin Cathedral) and beside it, under construction, is the cultural building Volkspalast, which substituted the former GDR parliament building. The construction of Volkspalast was heavily debated both among politicians and people in general.
Photo #3: In one of the pillars of the old buildings on Museum Island can still be seen bullet holes from the fightings at the end of World War II.
Photo #4: Zeughaus (Ammunition building) is the oldest structure of the former parade avenue Unter den Linden, with parts from the beginning of the 18th century. Today it houses the German historical museum.
Photo #5: Brandenburger Tor (Brandenburg gate), located at the opposite end of Unter den Linden, is a war victory monument from the end of the 18th century. This is probably the best known landmark of Berlin still today.
Photos #6 and #7: Two photos showing what is left today of the former Wall that divided the two major parts of Berlin between 1961 and 1989. Photo # 6 is from Bernauer Strasse, taken from the former West Berlin, showing a 60 m long part of the Wall that is kept as a remembrance still today. Behind it, on the former East Berlin is now located Gedenkstätte Berliner Mauer (Berlin Wall Memorial). Photo # 7 shows one of the memorial plaques spread out all over Berlin on the exact locations of the former Wall.
Photo #8: Checkpoint C(harlie), the best known crossing points between West and East Berlin, active between 1947 and 1991. On the right side of the photo is a sign saying, in English, Russian, French, and German “You are leaving the American sector”.
More about Berlin can be found in reference #2 below.
Today, I listened to an interesting live transmission by Radio Sweden from Berlin. The reporters were standing on Bernauer Strasse, exactly on the place where I took photo #6 12 years ago. If you understand Swedish, listen to the program, see reference # 3 below.
Finally, Berlin also makes part of my series of cities around the world that has been the host of an Olympic Game. It happened in 1936, when the Summer Olympic Games were held here, with the Olympic stadium I mentioned above in my visit in 1970 being the main venue. See reference #4 below.
During the month of October, my daughter Karina had the pleasure of presenting a project related to NLP (Natural Language Processing) at an international conference for AI (Artificial Intelligence) in Salvador, Bahia, Brazil.
While still being a Portuguese colony, during the 16th century, São Salvador da Bahia de Todos os Santos, or just Salvador for short, became the first capital of Brazil, before it later on moved to Rio de Janeiro and Brasília. Here are some nice pictures from Salvador. See also reference # 1 below.
Today I received more details from the conference I mentioned above. It was called STIL – XII Brazilian Symposium in Information and Human Language Technology and was held in Salvador on 2019-10-15 – – 18, bringing together both academic and industrial participants working in the areas of Linguistics, Computer Science, Psycholinguistics, Information Science, etc.
STIL also had three different collocated events, one of them being VI Student Workshop on Information and Human Language Technology (TILic). It was at TILic that Karina presented her project, Research of the use of word embeddings for calculation of similarity in translation memories, with the following abstract:
“The strategy traditionally employed by the CAT tools to match the segments of the phrase being currently translated with the segments present in the translation memory considers the intersection of the sequence of words (n-grams) present in the segments of the text being compared. However, this strategy is not capable of capturing semantic similarities beyond the trivial level. This study therefore presents a project with the aim of investigating the applicability of monolingual and bilingual word embeddings to implement the matching. The study is still in its initial phase of development. In sequence, there will be proposed and implemented a strategy for the calculation of similarity using word embeddings, which will be incorporated in a open source CAT tool. In order to evaluate the proposed strategies, the quality of matching in the baseline system (a version of a CAT system without any modification) will be compared to those of the system in which the proposed method will be implemented. At the conclusion of this project is expected to have obtained a strategy based on semantic similarity that will be an alternative to the traditional matching strategy based on n-grams. Although there are already texts covering the use of word embeddings to detect the textual similarity and cleaning of translation memories, there is no literature about any work that has investigated the objective of this project. Consequently, this study should be considered as the first initiative to an investigation within this context.”
In ref. # 2 below is the complete presentation (in Portuguese).
And here are three photos from the event. It shows Karina and her colleague João Gabriel Melo Barbirato, who presented a project named “Linguistic improvements on the text-image aligner LinkPICS”.
There is finally something really BIG happening in the world of serial communication between electronic devices. Last Thursday, 2019-08-29, was officialized the release of a new version of the popular USB interface, version 4, USB4 to be short, with a maximum data rate of 40 Gbit/s. See also reference #1 below.
From RS-232 to USB4
So, what is so special with this version then? Well, it seems that we now, almost 60 years after the RS-232 serial protocol was introduced, have returned to only one standard, regardless of the brand of the device.
It all started in 1960, when the American industry organisation EIA (Electronic Industries Association) introduced the RS-232 standard, initially to be used between electromechanical teletypewriters as DTEs (data terminal equipment) and modems as DCEs (data circuit-terminating/communication equipment). According to today’s standards, it was extremely slow, maximum 20 kbits/s.
RS-232 had some successors, such as RS-422 and RS-485, where both the speed and maximum cable length had been improved. For example, RS-422 is specified for a maximum bitrate of 10 Mbits/s and a maximum cable length of 1500 m.
We now jump to the 1990s, when the emerging personal computer (PC) industry found that maintaining the RS-232 communication was not feasible. There were then started two different initiatives to make communication between a PC and its peripherals much easier and faster. On January 1, 1996, was released the first version of the universal serial bus (USB). It had been developed by a consortium of companies such as Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. The data rate of USB 1.0 was 12 Mbits/s, which was improved to 480 Mbits/s with version 2.0 in 2001 and 5 Gbits/s through USB 3.0 in 2014, 10 Gbits/s by USB 3.1 in 2014, and 20 Gbits/s specified by USB 3.2 in 2017.
As you can see above, Apple did not participate in the USB consortium. Instead they had decided to develop their own communication interface, and attracted other companies such as Sony, Panasonic, Philips, LG, Toshiba, Hitachi, Canon, Thomson, and Texas Instruments. This group developed what came to be known as FireWire 400, aka standard IEEE 1394-1995. The data rate of this version was a maximum of 400 Mbits/s in half-duplex mode. It was followed by FireWire 800, which reached the speed of its name in 2006. However, Steve Jobs declared that FireWire was dead in 2008 when many camcorders were still using USB 2.0, instead of the faster FireWire.
Intel, which as you saw before already was a leading force in the USB consortium, now started to develop a new hardware interface together with Apple. It was dubbed Thunderbolt, and the first version appeared on MacBook Pro computers in 2011. Sony also used it in a Vaio line of notebooks in 2011. It was later followed by Thunderbolt 2 in 2013, with a maximum data rate of 20 Gbits/s.
And then, in 2016, Thunderbolt 3 was introduced, and as of now we can see that both standards are coming closer to each other, because they share the same USB-C connector. Intel decided in April 2019 to release the Thunderbolt without charging royalties from the companies who would use it, and that was the signal to finally use Thunderbolt 3 as a starting point for the specification of USB 4.
Will this mean that there is now unanimity in the electronics industry to start using only USB 4? Let us hope so, and that we will see the concrete result starting to appear in about a year or so.
There is much more to be said about this interesting topic of data communication, please see references # 2 through 7 below for details.
If you can’t beat them, join them!
A big problem in the crazy traffic in major cities around the world is of course that so many different categories of people on the move need to share the same physical space. Maybe the most troublesome is when motorbikes try to squeeze their way through in the small corridors between the cars. In 1997, when the most recent Brazilian Code for traffic was published, it permitted that they could do so, contrary to safety measures. And as a consequence, every day quite a few of those bikers are involved in severe accidents, even deaths.
However, one of the ways to mitigate somewhat this conflict was created in 2013 in São Paulo. You can see it in the photo above, taken downtown on 2019-08-09 at Avenida Ipiranga. It shows that motorbikers and other bikers, as well, have a privileged zone in front of the cars, when they need to stop for a red light. That way, when the light turns into green, they can speed away without needing to negotiate space with the car drivers. This method is called “Frente segura”, which means ‘Safe front’. More about it can be seen in reference #8 below (in Portuguese).
There are a new number of things from Brazil that I would like to publish here on my blog, so here they come!
Gripen is in the air !
Yesterday we received the thrilling news that the first of the new Gripen fighter series on contract from FAB, the Brazilian Air Force, has made its maiden voyage.
See reference #1 below for all the details.
I would like to take this opportunity to present a tribute to all my friends at Saab and FAB, both in Sweden and Brazil, and congratulate them on what they have accomplished so far and wish them success in their continued missions.
Yet another month has passed by, and what a month it has been! In my most recent post, on 2019-06-21, I talked about the international space station (ISS) and even made an update later on. But here comes more!
1. More about ISS
Further to my previous facts about the ISS, the following also deserves to be told.
We saw a most spectacular flyover in the early hours of 2019-07-22, about one hour before the sun rise. It came in from the North West and left us in the South East. The whole passing over the American continent took exactly 27 minutes, from the entry close to Oil City, WA, USA until the exit on the shores of the Brazilian state of Santa Catarina by the town of Barra Velha.
Below you can see two instances of its route, first when it was at its highest peak for our viewing, in the town of Inajá, state of Paraná, 35 km away from our location, and then after 5 more seconds, when even our town appears on the Google map below the world chart.
In reference #1 below is a link to the web site from which the above maps were taken, and reference #2 gives extensive background information about the ISS.
And finally, here is a photo taken at the same moment:
2. Walking on the moon
Everybody has of course heard about the historic feat in July 1969 when two American astronauts first set foot on the moon. But do you know the story behind the spacesuit that they wore?
It was made by the International Latex Corporation at their Playtex division, known for producing female garment. Their employees were responsible for manually sewing all the 4 000 pieces that made up each spacesuit. It consisted of 21 layers of synthetics, neoprene rubber and metallized polyester films, which protected Neil Armstrong and Buzz Aldrin from the extreme climate conditions on the moon surface. Each suit cost in the region of US$ 100 000 to US$ 250 000!
Read more about this fantastic story in reference #3 below. And in reference #4 is mentioned a book called ‘The golden thread’ in which the author Kassia Saint Clair gives even more details about the whole process of developing and manufacturing this lunar edition of a spacesuit.
3. Dog years
In my post of 2016-06-14, I wrote about our dog Prins, who has was commemorating his 7th birthday, counted in human years, that day. Thus, last month he completed 10 human years.
However, as I also wrote then, the second year and onward for a dog corresponds to a 7 times longer period of time. That means that last Sunday, 2019-07-28, Prins turned himself into the oldest living creature in our family, at least within his conception!
And here is a photo of Prins in his spacesuit, somewhat cheaper than Neil’s and Buzz’s, but equally well made by his human mother:
Today is the brightest day of the year on the Northern hemisphere, it is the day of the Summer solstice. You may remember that I already wrote about it briefly three years ago, on 2016-03-20, but here are some more interesting facts:
1. Summer solstice
The Summer solstice is the day of the year when one of the Earth’s hemispheres is located as close to the sun as possible. On the Northern hemisphere it happens around June 21 and on the Southern hemisphere around December 21. As a consequence, this is also the longest day of the year, considering the time from sun rise to sun set. But it also means that on the opposite hemisphere, it is the shortest day of the year. Read reference # 1 below for more information about the solstice.
So, which is the difference in duration of daylight in a particular place, if we compare those two dates? Well, the closer you live to the North Pole or the South Pole, the bigger the difference in time. You have probably heard about the expression “Midnight sun”, which is a phenomenon observed by those who live within the Arctic circle. As an example, in Kiruna, the northernmost city in Sweden, this year its habitants are lucky to have days with 24 h daylight from May 28 all through to July 16, a total of 50 days! But at the time around the December equinox, it is of course the opposite. From December 11, 2019 to January 1, 2020, during a total of 22 whole days, the Sun does not appear above the horizon not even a single minute!
And the closer one lives to the Equator, the less difference in time between the longest and the shortest day of the year. As an example, in Manaus, the capital of the Brazilian state of Amazônia, located 2 degrees South of the Equator, the difference is only 22 minutes, and in Macapá, the capital of the Brazilian state of Amapá, located exactly on the Equator, every day in 2019 is 12 h 7 min long. In my town Paranavaí, located slightly North of the tropic of the Capricorn, thus within the tropics, today is only 10 h 43 min long, whereas on December 21 it will be 13 h 34 min, a difference of 2 h 51 min. Reference #2 below has a link to a site that gives such information for any place on Earth, well worth studying.
2. UTC #1
And speaking about time, maybe you have noticed that the old abbreviation GMT (which stands for Greenwich Mean Time) is more often these days exchanged to UTC, how come?
I believe it is a matter of jealousy. Although the time settings for the globe are maintained within a zero meridian passing through the Greenwich observatory in UK, why should the British people have the privilege also to the name? So instead, UTC was introduced. Now, what does UTC stands for, exactly?
The fact is that it is a fabricated “abbreviation” involving English and French. Some centuries ago, the French had their own zero meridian for time, passing through Paris, but they had to succumb to Greenwich in that sense. So, as a compromise, they managed to enforce the denomination UTC. In English it would be similar to “Coordinated Universal Time” (CUT), and in French “Temps Universel Coordonné” (TUC), so UTC is not a bad compromise. Reference #3 has the whole story about it.
3. UTC #2
While I was doing research about UTC #1, I remembered that UTC is also the (real) abbreviation of a technical university in France, where I studied in the 1970s. I already wrote something about it on 2017-11-11, but here comes more. This UTC means Université de Technologie de Compiègne. It is a technical university belonging to the French state, created in 1972, and since 2012 it makes part of the group of Sorbonne Universities. It has a reputation of being more integrated into the society, with frequent trainee periods in the French industry, as well as many interchange programs with other international universities, than the traditional theoretical French technical universities, e.g. École Polytechnique.
I studied there between September, 1978 and June, 1979, exactly 40 years ago. During that year happened an interesting fact, a group of students from China came to study at our university. It was a sensation at that time, because China was extremely closed to external activities. This photo shows the Chinese students, taken in February, 1979. They have since kept the contact and met year after year and update themselves. See also reference # 4 below. At the bottom of that page you can also find the complete magazine edition of April 2019, both in French and English.
4. ISS flies over Paranavaí
The sensation today here in my home town was the passing of the international space station (ISS). I had heard about it before, that it would be possible to see it with the naked eye, but never had the chance to actually see it. See also reference #5 with the announcement.
Update on 2019-07-12
Today we had a chance of viewing the ISS even better and for longer. And it did not hurt at all that the moon was eager to also play a vital part of the scene, being half way between the crescent and full moon phases. See the photo below. Reference #6, which tells the ISS passing date and time for any location on the earth, said the following about this event:
I owe a big apology to all my faithful readers for having been absent with new posts for almost two months, so let me make it up today with a quite few interesting facts:
1. Image of a black hole
During the month of April, we received the astonishing news that astronomers had finally managed to catch a black hole on film. The image was captured by the Event Horizon telescope (EHT), a network of eight radio telescopes spanning locations from Antarctica to Spain and Chile, in an effort involving more than 200 scientists. Read more about it in ref. #1 below.
2. Late Easter (continuation from earlier post)
In my post of 2019-03-05 I wrote about the late date of Easter this year, and as you may remember my friend, the German-Swedish meteorologist André Franke explained it all for us.
However, I have received comments about this subject. In 2019, the March equinox occurred on March 20, and there was a full moon already the next day, March 21. So, why was not Easter Sunday celebrated on March 24? André can explain that, as well. It is quite complicated, but here is the short explanation:
It all started in year 325, when the First Church Council of Nicaea among other things decided that the March equinox should always fall on March 21, and then Easter Sunday would always be the first Sunday following the first full month after the March equinox. But as we know, the Earth’s rotation around the Sun is not exactly 365 days. It is approximately 6 h more, and that causes that the fixed March equinox day is not always the same actual, astronomical day for the same equinox, as happened this year.
If you want know the long story, take a look at reference #2. Unfortunately, it is written in Swedish, but there are many other sources around the internet that can tell the same story.
Baarle is a village right on the border between the Netherlands and Belgium. 91 % of the total area of the village belongs to the Dutch, the rest is Belgian. But it is not a clean cut, there are in fact 16 Belgian exclaves within the Dutch territory, and they in turn surround seven Dutch areas. See also reference #3 below. Thanks to Radio Sweden’s Andreas Liljeheden for yet another idea to an interesting blog fact, see also ref. 4 below! (You may remember Andreas’s earlier contribution to my blog on 2018-10-20, when he presented the donkey steps in the EU headquarters in Brussels.)
4. Different maps of the world
One of my interests is maps, traditional, historic, different kinds of maps – you name them! It is therefore a great pleasure for me to present a total of 45 different maps of the world, the big majority of them are without doubt something you have never seen before. Click on the link of ref. #5 below and start being amazed. (I like maps #1, 2, 7, 8, …)
Very recently, I received two pieces of sport news from Sweden which really made me both laugh and admire the initiative force of Swedish female athletes of all ages.
The first one is about curling. One week ago, Switzerland beat Sweden in the final of the women’s world championships, held in Silkeborg, Denmark, situated close to what was once considered to be highest point in Denmark. As you can see from this slogan, Danish mountain climbers have a blast there:
By the way, the highest peak here, called Himmelbjerget (which means the mountain of heaven) reaches impressive 147 m! See also reference #1 below.
But getting back to curling, one of the members of the Swedish team is called Agnes Knochenhauer. She won a gold medal in the Winter Olympics in PyeongChang in 2018, and after that, she and her team mates have won the European Championships and twice been runner up at the World Championships. In January this year, the same team from Sundbybergs CK also played in the Swedish Championships, held in Jönköping. Agnes let her 7-year old daughter, Tilda, visit the games together with her mother. Tilda has already started her own career and when the team skip, Anna Hasselborg, got sick, Tilda jumped in and replaced Anna, not as a skip, but as one of the other players. The result was beyond expectation, the team won the championships and little Tilda can now put Swedish adult champion on her business card! See also reference #2 below.
And yesterday happened another interesting fact. During the last day of the Swedish Championships in biathlon, which had relay races on the program, another Olympic champion from PyeongChang, Hanna Öberg, also got sick and could not participate together with her teams mates in the women’s team event. That meant that her club, Piteå SSK, had to withdraw from the competition. But one of the two other team mates, Anna Magnusson, won a bronze medal nevertheless! She participated in the men’s (!) relay race with two male colleagues. See also reference #3 below.