2020-08-31 (Monday)

Today, I learned about:

There are so many interesting things happening outside our small Earth, in the vast space of the Cosmos. I recently took a course on the edX MOOC (massive open online course) from the mighty MIT, Massachusetts Institute of Technology. The course had the title “Introduction to Aerospace Engineering: Astronautics and Human Spaceflight.”

What made the course so exceptionally interesting was, besides the contents with plenty of video clips further to the traditional Power Point style lectures, that the teacher of the course was no one less than an ex-NASA astronaut, Jeffrey A. Hoffman. His first space flight was in the first servicing mission of the Hubble telescope in December, 1993, and after that he participated in four more missions to the international space station ISS. Only a live astronaut can make a course like this even more interesting by telling his personal experience of those missions. See also reference #1 below.

Astronauts Franklin Story Musgrave and Jeffrey Hoffman install corrective optics during the first service mission to the Hubble telescope in December 1993. Photo courtesy by NASA.

Another interesting fact about the big wide space was published in June, 2020, by Popular Mechanics. It is a story about how a pulsar prepared itself to eat up a nearby star and released an outburst of cosmic X-rays thousands of times brighter than the sun!

Astronomers captured the “power up” sequence of a pulsar right before it gobbled up gas and dust from a nearby star and shot a burst of X-rays into space. It is the first time they have captured this entire process before. The research, astronomers say, will help us understand how pulsar outbursts form. Photo courtesy by NASA.

That’s what I learned in school !

Ref.:

1: Hubble Space Telescope, Servicing Mission 1

*: What did you learn in school today ?

2020-07-31 (Clash of titans!)

Today, I learned about:

At midnight today we will stand before a fact that only happens once in a calendar year. You might remember from your school days a mnemonic to remember the length of a certain month. Start with your left hand and where there is knuckle that corresponding month has 31 days, the valleys in between are for months with normally 30 days, except for February. Put your to hands together and you have two knuckles without any valley between them. This is of course July and August.

So how come this phenomenon? This, as many other things, has its origin in Rome, around the beginning of the Christian era of counting the years. The former month namned sextilis, meaning the sixth month, was renamed to that of Emperor Augustus as a tribute to his many feats during that certain month. But why 31 days also in August, and as in July? There is a common misconception, invented in 13th century, that Augustus wanted to have his month equal to that of the great Julius Caesar. Well, that is fake news! It is was already that way when the Julian calendar was introduced by Julius Caesar in the year 45 BC. And furthermore, the two consecutive months December and January, both also have 31 days. So, really, there is no good, plausible reason for this question. See also reference # 1 below.

Now over to some geography. My good old friend Arthur and his family recently visited the Grand Duchy of Luxemburg. And as you have seen before, when they travel, my friends spread out over the world, remember me! They send me photos of the place, so that I can show them to you. My warmest thanks to Arthur, and all his predecessors in this great habit!

The header photo was taken in the center of the capital of Luxembourg, which also is called Luxembourg (and sometimes Luxembourg City)! The building in the middle is famous for, among our things, to have been the seat of the High Authority of the ECSC (European Coal and Steel Community), consisting of six member countries. This was the origin of the current European Union (EU), and the High Authority these days is called the European Commission. So it is no coincidence that you see all those flags from Luxembourg and the EU in the forefront. See also references # 2 and 3 below.

Below are some more photos from Luxembourg, enjoy!

Photos from Luxembourg City, all taken on 2020-07-16 by Arthur Ribas Teixeira

You have probably heard and seen that NASA has sent another mission to explore Mars. It was launched yesterday, and as a tribute, all articles in a newsletter from HowStuffWorks (HSW) on the same day were also about Mars, quite interesting stuff! In reference # 4 below is an article the new NASA Perseverance Rover which will search for signs of a ancient Martian Life. Look up the article and while you are on the HSW website, I suggest you sign up for their newsletter, so that you will have many interesting stories to read in the future.

The following subject is something that is constantly on everyone’s mind these days, the Covid-19 pandemic. So, why not take it from the humorous side, for once?

BACK TO SCHOOL! Cartoon made by Benett, published in Folha de S. Paulo on 2020-07-30

Finally, tomorrow I will celebrate the 10th anniversary of my favourite online game, Wordfeud. I have been addicted since April, 2012. Don’t know Wordfeud? Look at my post from 2016-03-18 !

That’s what I learned in school !

Ref.:

1: Julian calendar

2: History of the European Coal and Steel Community (1945–1957)

3: Luxembourg City

4: NASA’s Perseverance Rover to Search for Signs of Ancient Martian Life

*: What did you learn in school today ?

2020-06-30 (End of 1st half!)

Today, I learned about:

This first half of the year has been nothing like I, and everybody else, could imagine. 2020 looked so nice, symmetrical, and of course we had hopes and beliefs that it would be a very good year. How wrong we all were! But let us hope that the second half of 2020 contributes with better moments.

As you probably remember, I already told you that there is a computer application that I cannot think of living without, the electronic spreadsheet. See also my post of 2017-11-17 .

In three weeks time, July 21-23, there will be an interesting 50-hour webinar, in which Microsoft’s most valuable professionals (MVPs) will cover various aspects of using Excel. Of course there are many interesting subjects in the conference, but if I could only pick out only one, then it would be “Integrating Python and Excel”, where Tony Roberts on July 22 at 11:00 GMT explains how to bring the trendy programming language Python to work with Excel, thus expanding the possibilities of creating user defined functions (UDFs), today only possible through Macros developed in VBA. See also reference #1 below.

That’s what I learned in school !

Ref.:

1: Excel virtually global

*: What did you learn in school today ?

2020-05-01 (Sköna maj välkommen!)

Today, I learned about:

Nothing is like it used to be. Yesterday was April 30, the day that Sweden is used to celebrate the arrival of Spring with various fun events during Valborgsmässoafton (Walpurgis night). The whole story started already during the 8th and 9th century in England. You can read more about it in reference #1 below.

One popular tradition on that day in Gothenburg, Sweden’s second biggest city, is the Cortège, when the first-years students at Chalmers University of Technology give their review of the events of the preceding year in a carnival-style parade. The header photo today was taken during the Cortège in 1977. I had the pleasure of participating in it two years earlier and I must admit it was really a treat.

Another tradition on that day is to light bonfires as a way to keep the evil spirits away, and especially in the old university cities of Uppsala and Lund people gather to hear the students choirs sing their traditional songs praising Spring.

But, nothing of that sort happened yesterday. The COVID-19 pandemic impeded all those traditions to be celebrated once more. It was therefore a pleasant surprise what Radio Sweden had in store for us.

The classical music channel P2 had invited its listeners to contribute in a special way, by recording their voices and faces when singing the traditional song Längtan till landet (I am longing for the countryside). See reference 2 below for the P2 page and reference 3 for the video with the song.

And if you want to sing along with all the other 707 singers in the choir, here are the lyrics:

I dedicate this post to my dear old friend Bosse, who took so well care of me from the moment I first arrived in Brazil. He loves this kind of music, his idol is the late Jussi Björling, need I say more? For those who do not recognise that name, let us compare him to later day tenors like Luciano Pavarotti, Plácido Domingo, and José Carreras. See also reference 4 below.

That’s what I learned in school !

Ref.:

1: Walpurgis Night

2: Hela Sverige sjunger in våren!

3: Hela Sverige sjunger i P2:s valborgskör

4: Jussi Björling

*: What did you learn in school today ?

2020-04-01 (Corona relief ?)

Today, I learned about:

I just heard an interesting piece of news. It seems that the WHO (World Health Organisation) and the WCSF (World Cruise Ship Federation), which has all the big cruise ship companies among its associates, are close to conclude a deal which may be a big relief for those people who need to be treated because of COVID-19, the corona virus pandemic that is keeping the world at a still.

Two cruise ships exploring the Baltic Sea, photo taken in July 2019.

The idea is that since WCSF cannot keep their ships running normally due to all docking restrictions, they want to show the world that their ships are not only meant for luxury cruises for those with plenty of money, but also for normal people who never would have a chance of coming close to such a ship. So instead of trying to find space for treatment in the saturated, normal health care system and its hospitals, the ships would be anchored on a sufficient distance from land to not disturb life on shore, and yet offer plenty of rooms and beds for the necessary health procedures and recovery.

Keep your eyes and ears open, the official announcement should come any minute now.

The idea of using a ship as a hospital is not new, there are indications that the Greek had some already in ancient times. The British included a hospital ship in their Navy in the 17th century, many hospital ships were of course used during World Wars I and II, and just two days ago, the USNS Confort docked in New York City to help treating corona patients there. See also references #1 and 2 below.

USNS Confort, photo by Spc. Landon Stephenson on April 11, 2009

That’s what I learned in school !

Ref.:

1: Hospital ship

2: Everything you need to know about the USNS Comfort, the giant hospital ship in NYC

*: What did you learn in school today ?

2020-03-24 (40 anos!)

Today, I learned about:

Exactly four years have gone since I wrote a post about when I first set foot on Brazilian soil. That time, 36 years had gone since that historical step, 2016-03-24.

And here we are again, four years older, and maybe even wiser! So today makes 40 years since I came to Brazil as a trainee engineer, who would think that I would end up here? But here I am, and frankly speaking, I cannot complain! Life has been tough, but I have had my golden days, as well. And to celebrate those 40 years, what could be better than the Brazilian national drink, caipirinha? It is so easy to make and it is refreshingly tasteful. Look at another post, 2016-02-14, for the recipe and a photo. Saúde, cheers, skål !

All about COVID-19

I know that many of you are exactly in the same situation right now as I am, locked down at home, waiting for that nasty corona virus to disappear. The Chinese e-commerce giant Alibaba has elaborated and published a comprehensive story about what it is, how to treat it, etc. In ref. # 1 below, there is a copy of their report, it is really worth reading! And if you are so inclined, Alibaba is asking for volunteers to help translate the book into Korean and European Portuguese. More about that in ref. # 2 below.

That’s what I learned in school !

Ref.:

1: Handbook of COVID-19 Prevention and Treatment

2: Jack Ma Foundation shares coronavirus; prevention handbook

*: What did you learn in school today ?

2020-02-29 (Leap day!)

Today, I learned about:

Exactly four years have gone since I last wrote about what a leap day is, 2016-02-29.

And here we are again, four years older, and maybe even wiser! I was thinking about the poor guy that was born on 1896-02-29. He celebrated his birthday on the correct date of the year only when there were eight candles on his birthday cake. How come? Well, as you know a leap year normally happens only once every four years, but when the century is on its first year, then it must also be evenly divided by 400, i.e. 1600, 2000, 2400 etc. But then, he knew that if he lived that long, he would still celebrate it on the correct day with 12, 16, 20, 24, … candles!

‘Can you use an hourglass’?

Finally, here comes the solution to the riddle posted back in 2019-12-31:

You start with two loaded hourglasses at the same time. After 7 min, when the small hourglass is done, you turn it over and restart it.

After 11 min, when the big hourglass is done, you leave it as it is. But now you turn over the small hourglass, which has had a second run of 4 min, and let it run for the third time until it stops.

Voilà, you have now accomplished the task!

That’s what I learned in school !

Ref.:

*: What did you learn in school today ?

2020-01-09 (4 years!)

Today, I learned about:

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

and

15 – 11 = 4

Can you solve it now?

A complete solution will be presented in my next post.

That’s what I learned in school !

Ref.:

*: What did you learn in school today ?

2019-12-31 (Réveillon!)

Today, I learned about:

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:

It all starts in the upper middle section of the sketch. The solar reflector (SOLFÅNGARE) placed on the roof of a building captures the sun’s rays. The parabolic section concentrates solar energy and transmits it to the liquid in the tube in the center of the solar reflector. From there, the cold liquid, now containing stored chemical energy, is sent to an energy storage (ENERGILAGER). It can be stored there for up to 18 years! When we need to heat up our house, we simply let some of the liquid out from storage, run it through the catalyst (KATALYSATOR), thus obtaining a hot liquid without any stored chemical energy. Experiments have shown that the liquid with released heat can have a temperature that is 63 °C higher after the catalyst in relation to before! The hot liquid then goes into the normal heating system of the house, e.g. the radiators (ELEMENT I HUS) in the various rooms, heats up the ambient, and then the now cold liquid goes back up to the roof to capture more sun rays. Graphic made by Yen Strandqvist.
The leftmost photo shows the parabolic solar reflector with the liquid tube in the center. To the right is the inventor of the material, professor Kasper Moth-Poulsen, securing a small sample of the miraculous liquid. All material has been extracted from Chalmers Magasin no. 1 2019, text by Karin Aase and photos taken by Oscar Mattsson and Johan Bodell.

References # 1 through 4 below contain more material if you are interested in further details.

Can you use an hourglass?

According to Wikipedia: “An hourglass (or sandglass, sand timer, sand clock or egg timer) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one. Typically the upper and lower bulbs are symmetric so that the hourglass will measure the same duration regardless of orientation. The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter, the bulb size, and the neck width.

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!

That’s what I learned in school !

Refs.:

1: Extract from Chalmers Magasin nr 1 2019 (article in Swedish)

2: An energy breakthrough could store solar power for decades

3: Storing the energy from the sun for decades

4: Liquid sunlight creates heat on demand

*: What did you learn in school today ?

2019-11-09 (The Wall)

Today, I learned about:

Berlin 1970

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.

See also my post of 2016-05-08 .

Berlin 2007

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.

The guided city walk of started at Hackescher Markt in the central part of Berlin and ended at the former Checkpoint Charlie. The explanation to the photos is in the text below. On top is photo 5. The next row, from left to right, photos 2 and 4. Middle row, from left to right, photos 6 and 7. Lower row, from left to right, photos 1, 3, and 8.

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.

Berlin 2019

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.

That’s what I learned in school !

Refs.:

1: Trelleborg–Sassnitz

2: Berlin

3: Murens fall 30 år. Direktsänt från Berlin!

4: 1936 Summer Olympics

*: What did you learn in school today ?