2019-06-21 (Midsommarafton)

Today, I learned that:

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.

The group of Chinese pioneers who studied engineering at Université de Technologie de Compiègne, France. This picture was taken in February 1979, when they has just arrived at the university.

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:

A photo of the international space station en route passing over Paranavaí, PR, Brazil. The ISS is the small dot you can see up in the left corner, appearing together with an almost full moon. This photo was taken on 2019-07-12 at 19.25 local time.

That’s what I learned in school !


1: Solstice

2: Kiruna, Sweden — Sunrise, Sunset, and Daylength, June 2019

3: Coordinated Universal Time

4: Des étudiants chinois à l’UTC depuis 40 ans

5: Estação Espacial poderá ser vista novamente no céu de Paranavaí

6: 10-day predictions for satellites of special interest

*: What did you learn in school today ?

2017-11-11 (Saturday)

Today, I learned that:

Exactly 39 years ago today, I was studying in the French city of Compiègne, located 80 km north of Paris. And on that very day, there was a big crowd coming into the city to celebrate the 60th anniversary of the signing of the armistice agreement of the first world war between France and Germany. The signing had taken place in a railway car in the forest of Compiègne, and the railway car is still there close to the original site, and copies of the documents and utensils used for the signing can still be found inside. However, the car as such is also only a replica, the original one was confiscated as a war bounty when Germany invaded France in June, 1940. The following painting of the 1918 event is also considered to be not totally true to the original. More information can be found in references #1, 2 and 3 below.


This image appears to be a painting, not a colourized photograph. (It might have also been published as a sepia postcard.) The probability that it is not a photograph is also indicated by the inaccurate depiction of furniture, in Maréchal Foch’s ‘dining car’, which had a fixed-to-the-floor table and French chairs (as seen in photographs of the event). The probable inaccuracy of the depiction might be the reason for its anonymity.

Then, on the very same day 4 years later, I had the pleasure of going to a concert with the Swedish singer Lill Lindfors. After the concert, she signed her portrait with a dedication to me. In reference # 4 you can read more about her and references # 5 and 6 give links to one of the songs she sang then. In Swedish the title is Teresa (about a young girl and her dreams), whereas the original Brazilian title is Tristeza (which means sadness, but you can make it go away when you sing, just like Elis Regina does here). ENJOY!


The newspaper insert from Svenska Dagbladet reads, translated into English : “Lill finishes her concert tour in Akalla. Lill Lindfors will give her last concert of the tour she is making in the outer suburbs of Stockholm tonight at 19.30 at Akalla Träff. The set list is based on the theme of longing and it is a performance of songs and music, where also the trio Anders Ekdahl (piano), Jan Bergman (base guitar) and Ola Brunkert (drums) participates.”

Finally, today’s photo shows the Ayrton Senna bridge joining the Brazilian states of Mato Grosso do Sul and Paraná. On the right side can be seen the city of Guaíra, PR. Photo taken on 2017-10-28. See also my post from 2016-11-30.

Ponte Ayrton Senna 2017

Ponte Ayrton Senna, the bridge that joins the Brazilian states of Mato Grosso do Sul and Paraná. In the right corner can be seen the city of Guaíra, PR. Photo taken on 2107-10-28.


That’s what I learned in school !


1: Forest of Compiègne

2: Compiègne Wagon

3: Painting of November 11, 1918

4: Lill Lindfors

5: Lill Lindfors – Teresa, 1987

6: Elis Regina – Tristeza, 1965-1968.

*: What did you learn in school today ?

2016-01-15 (Fredag)

Idag fick jag mig en påminnelse om:

Att bada i 4-gradigt vatten, i en vak som tillfälligt hålls isfri på en i övrigt istäckt sjö kan av många tyckas vara en aktivitet som de aldrig i livet skulle tänka sig att utföra. Men det är något som vinterbadarna njuter av varje dag under den kallaste årstiden. Jag hörde detta reportage av Niclas Odengård på SR Sjuhärad, som också har hjälpt mig att hitta en del av referenserna längre ned:


Kanske något att tänka på istället för att kura ihop sig inomhus? Själv minns jag när vi hade kalas i Chalmers studentkårs sportstuga i Härskogen, den 14 februari 1979, för ett gäng fransoser som liksom vi, utbytesstudenter från CTH på Université de Technologie de Compiègne, var i Göteborg på sportlovet. Efter mat, dryck och bastubad var det dags att visa våra gäster hur man svalkar sig i Sverige på vintern. Medan min franske kompis var nere i vattnet stod jag på bryggan i adamsdräkt, 22 minusgrader och snålblåst och längtade (!) att få avlösa honom i vaken. Och det är faktiskt något som jag minns än idag, när jag skriver detta i 30 plusgrader på andra sidan jordklotet.

… Tack för idag, slut för idag!

(This post in Swedish talks about the health benefits of winter swimming.)


1: http://sverigesradio.se/sida/artikel.aspx?programid=95&artikel=6343269

2: http://fof.se/tidning/2012/10/artikel/kylan-stressar-kroppen-och-det-ar-bra

3: http://www.vardagsfilosoferna.se/2015/03/23/hälsosamma-vinterbad-är-vanebildande-26169633

4: http://www.sciencedirect.com/science/article/pii/S0031938404002616

5: http://www.sciencedirect.com/science/article/pii/S0306987703002706

+: https://www.youtube.com/watch?v=VucczIg98Gw