2016-02-29 (Monday)

Today, I learned that:

A day like today happens only once every 4 years, because the time it takes for the Earth to complete its orbit around the Sun in 365 days, 5 hours, 49 minutes, and 16 seconds. However, whereas a normal year is 365 days, adding one more day every 4 years results in adjusting that difference too much. So, during the course of 400 years, every fourth year receives an extra day, called leap day, with exception of the three initial years of the centuries, which are not exactly divisible by 400. This means that year 2000 was a leap year, but not 1900, 2100, 2200, 2300, 2500, etc.

The leap day was introduced in Rome already in the 1st century BC. Originally, and for a long time, it was February 24 that was considered the leap day. It was still that way when I lived in Sweden, but nowadays it is February 29 also there and in the rest of the EU, a change that occurred in year 2000.


The local politicians in the city of Paranavaí, state of Paraná, Brazil, agreed that “the more the better”, so on a leap day some years ago they decided to institute 6-way crossings in the city center.

Finally, according to a tradition that is said to go back to the Irish patron, Saint Patrick, today is the day for a woman to propose marriage to a man. So if you read this before midnight, there may still be time to achieve what you desire. Right, Linda?

… That’s what I learned in school !


1: Leap day

2: Skottår

+: What did you learn in school today ?

2016-02-28 (Sunday)

Today, I learned that:

The way the world is today, we had better be optimistic in order to not go down further. But at the same time, we have to be realistic, and thus today’s post is not at all positive.

The Swedes still remember what happened today exactly 30 years ago, when the country’s CEO, also entitled “statsminister” or prime minister, was murdered, and which led to a lot of investigations and confusions that have never been totally concluded, and I doubt they ever will.

But here in Brazil, the big news on that very same Friday was the economic plan launched by the Federal government, the Cruzado Plan. It was the first in a row of similar attemps to stop the inflation and get the country into a more stable state. Among the measures taken were the conversion of the old currency, cruzeiro (Cr$), into a new one, named cruzado (Cz$), where 1 Cz$ = 1 000 Cr$. Also, there was a general freeze on prices and salaries. In the beginning, the people in general were optimistic and believed that the plan might eventually succeed, but it became evident that the lack of corrective actions to address observed undesirable effects gradually resulted in a failure, with the inflation bouncing back at even higher levels than before.

So during the period from 1986-02-28 to 1994-07-01, Brazil had the following official currencies:
1986-02-28 — 1989-01-15 cruzado (Cz$). ISO 4217 code BRC.
1989-01-16 — 1990-03-15 cruzado novo (NCz$), where 1 NCz$ = 1 000 Cz$. ISO 4217 code BRN.
1990-03-16 — 1993-07-31 cruzeiro (Cr$), where 1 Cr$ = 1 000 NCz$. ISO 4217 code BRE.
1993-08-01 — 1994-06-30 cruzeiro real (CR$), where 1 CR$ = 1 000 Cr$. ISO 4217 code BRR.
Starting on 1994-07-01 and still today, the currency is named real (R$), which was converted at the rate of 1 R$ = 2 750 CR$. ISO 4217 code BRL.

It is very well worth noting how to the real was introduced. During the four months that preceded the adoption of the real, Brazil had two different currencies. The first one was of course the official currency, cruzeiro real, but there existed also a parallel non-monetary reference currency named URV (Unidade Real de de Valor, meaning Real Value Unit), and all prices and salaries were quoted in both currencies. The government published the daily ratio between the two currencies, which included a daily devaluation of the cruzado real in relation to the URV. A complete explanation of this gradual process of conversion can be found in reference # 2 below.

100 reais

The Brazilian bank note with the highest facial value. Today, 100 reais correspond to approximately 25 US dollars or 23 Euros.

And so, on 2016-07-01, if nothing happens before that date, Brazil will have survived 22 years with the same currency and an apparent, stable economy. Of course, the last statement is not really true, because there have been periods with rather high actual inflation, although not reflected in the official numbers, and as I hinted in the very first paragraph of today’s post, the situation is very critical. The high levels of corruption and lack of efficient policies to develop and sustain the economic growth has led to a political crisis of huge expression, combined with prolonged periods of negative economic growth. In fact, today one of the leading daily newspapers in Brazil, O Estado de S. Paulo, expressed in its main article that “Após três décadas, risco de calote volta a assombrar economia brasileira”, which means that three decades after the ecomic crises of the decade of 1980, there is imminent danger that Brazil will break through once again, as it did in 1980. Reference # 3 contains the complete article.


Hollywood Boulevard’s Walk of Fame, photo taken on 2007-02-20

After such a gloomy post, is there nothing positive that can be said today? Well, the photo above shows the hands and feet of some of the biggest stars in the history of the film industry, like Humphrey Bogart and Shirley Temple, for ever present in the Hollywood Boulevard’s Walk of Fame. And to my surprise, the Swedish current star, Alicia Vikander, native from the Swedish West Coast, was presented with the Academy Award (“Oscar”) for her role in the movie The Danish Girl, fantastic! So at least this day ended up with a positive splash!


Alicia Vikander holding and thanking for the Oscar statue. Photo by Kevin Winter/Getty Images

Updated 2016-02-29: Listen to Alicia thanking for the Oscar, reference #5 below. And further to Alicia’s own Oscar, the sci-fi thriller Ex Machina, where she plays a robot, also won an Oscar for the best visual effects, beating such heavy productions as The Martian, Mad Max: Fury Road and Star Wars: The Force Awakens, in spite of a minuscule budget of just $15 million.

… That’s what I learned in school !


1: Plano Cruzado

2: URV

3: Após três décadas, risco de calote volta a assombrar economia brasileira

4: Oscars 2016: Alicia Vikander wins Best Supporting Actress for The Danish Girl

5: Oscar till Alicia Vikander

6: ‘Ex Machina’s’ Oscar win is a triumph for low-budget VFX

+: What did you learn in school today ?

2016-02-27 (Saturday)

Today, I learned that:

The interest for solving riddles is big among my readers, and the first correct solution to The pill roulette was submitted by Barbara and her colleagues at Torpaskolan in Gothenburg, Sweden. Congratulations to all you clever people! And here comes the …

Solution to The pill roulette, posted on 2016-02-21

  • Divide the eight pills into three different piles, two having three pills each and one with two pills.
  • Place one pile with three pills on the left pan of the balance scale and the other pile of three pills on the right pan.
  • If the weighing results in equality, then we know that all those six pills are also equal and none is poisonous. A second weighing of the remaining two pills indicates which pill is the poisonous one, since it is a little heavier.
  • However, if the first weighing results in that the total mass (“weight”) of one pile with three pills is heavier than the other pile of three, then we know that both the lighter pile of three and the sided two pills are all normal pills without any poision. Thus concentrate on the heaviest pile of three, one of the pills in it is the poisonous one. Take any two of those three pills and place one each on either pan of the balance scale. If this second weighing results in equality, both of the two pills are OK, and the sided third pill is the poisonous one. But if one of the two pills on the scale is heavier than the other one, it is the poisionous one!

A new riddle can be found at the end of today’s blog.

The Internet of Things

Last week was a busy one in Barcelona, Spain, where the Mobile World Congress gathered many people to learn and spread the word about the current state of affairs. Today, I will restrict the field to the so-called Internet of Things (IoT), which is the increasing number of appliances, gadgets, vehicles, etc. that connect and interchange information. Radio Sweden’s weekly financial update was entirely dedicated to IoT, giving specialists from Ericsson, Huawei, Nokia, and Oracle a chance to share their thoughts. For the complete program, listen to reference # 1 below, but if you do not cope very well with the Swedish language, I will give you some of what was discussed here:

  • IoT has been around for quite a while, although in a unorganized manner, through all the sensors that have reported various parameter values to centralized locations, which evolved to machine-to-machine communication (M2M) and now IoT.
  • Built-in sensors in our homes will warn us when all is not the way it should be, e.g. if there are leaks of water, gas, etc., and instead of us having to call for someone to come and help us during normal business hours, we will receive a message telling us about the current situation and asking us about when that someone would be welcome to come to our home and solve the problem.
  • The self-driving cars will be upon us soon.
  • Provided that we can guarantee that the communications are resistant to hacker attacks, people are willing to share the biomedical data remotely. And the 5G networks that soon will be available are said to offer so much more security than today’s technologies, because already from the start 5G has been created to serve IoT well, and not be just another broadband communication technology.
  • A test with connected garbage cans in Germany, where the garbage only was collected when the cans called and informed that they were full, showed a 50 % reduction in costs in relation to the traditional scheduled garbage collections.
  • If we compare the development of applications for IoT between USA and Western Europe, then there is an interesting remark. Whereas the American development is more concentrated to big corporations, in Western Europe there are many small companies involved and their flexibility and speed can result in launches of new products well ahead of their American competitors. Furthermore, we can already see a trend where small European companies win over their Asian competitors in providing products in smaller volumes tailored to their customers’ needs.
  • I already talked about 5G in my post on 2016-01-24, citing applications that demand the high speed of a 5G network to function adequately. Look at references #2 and #3 below, where it is explicitly shown in text, photos and videos from Barcelona.
  • Our pets will inform us where they are, how they are, if they are hungry, etc.

Connected dog, sending messages from a display on the collar or via Internet of Things

Riddle # 3 (The fast mover)
What can go from there to here by disappearing and then go from here to there by appearing? A solution to this riddle will be published next Saturday, 2016-03-05. The first person that comes across the correct solution and sends it to medieborgaren@sjson.com will receive an honorary mention.

Slutligen, Ordalaget har gjort det igen! Igår gav de oss ett nyord för en falsk ID-handling, en s.k. legimitation.

Svenskt körkort

Bonusfråga: Även om texten “SPECIMEN” inte funnes, så vore detta ett utmärkt exempel på en legimitation. Kan du lista ut varför? (Svar kommer tillsammans med lösningen på gåta nummer 3 ovan 2016-03-05)

… That’s what I learned in school ! … Slut för idag, tack för idag !


1: Sakernas internet och framtiden

2: 5G was the real star of Mobile World Congress

3: A true 5G demo

4: Legimitation

+: What did you learn in school today ?

2016-02-26 (Friday)

Today, I learned that:

When I talk with people in Sweden about the weather we have here in Brazil most of the year, many times I receive comments about how they envy me when I tell them about the temperature outside, the shining sun and the climate in general. I understand them perfectly, because to me it is much easier to get used to a hot climate than a cold one.

But nevertheless, can you imagine that there are people that pay big money to travel across the world to arrive in the North of Scandinavia during the coldest and darkest months? You have probably heard about the ice hotel in Jukkasjärvi, which is rebuilt every year so that tourists can go there and enjoy (???) some days in the ice box. If that thrills you, look at reference #1 below.

northern lights

Northern lights by Icehotel Jukkasjärvi

However, there is also another type of tourism that is having a great time right now, in the depth of the winter season, namely the people who use the harsh climate up in the North to squeezee out every little drop of excitement by driving a fabuolous car under the most stringent conditions. It started out some years ago, when the automotive manufacturers set up their test tracks in Arvidsjaur, and now this sort of activity is expanding to also invite motor enthusiasts to experience something very different. And for that purpose, there are companies that promote complete packages with lodging, food and of course tough winter driving. References #2 and #3 is about such a company.

… That’s what I learned in school !


1: Icehotel Jukkasjärvi

2: Exclusive car events

3: De flesta bileventföretagen är fullbokade

+: What did you learn in school today ?

2016-02-25 (Thursday)

Today, I learned that:

In our connected world, where everyone has a smartphone, do you ever give the ubiquitous communication technology a thought? It is true that the mobile phone networks (2G, 2.5G, 3G, 4G, …) play an important role, but frankly speaking Wi-Fi is the main player, right?

So how did Wi-Fi come about? I think that it is one the most important inventions ever made, but originally it was not meant as such. The whole story was told in the Australian Radio National’s Science Show by Brian Schmidt, Nobel laureate in Physics in 2011, on May 5, 2012. See reference #1 below, it is an amazing story!

And speaking about amazing, how about having the same Brian Schmidt and the marvellous educator Paul Francis teach you astrophysics without any cost? Details in reference # 2 below.


Paul Francis and Brian Schmidt introducing one of the astrophysics courses. © edX Inc.

Getting back to Wi-Fi, you have probably also noticed how much battery power is consumed when the Wi-Fi functionality is switched on. But here comes good news:
A team of University of Washington computer scientists and electrical engineers has demonstrated that it is possible to generate Wi-Fi transmissions using 10 000 times less power than conventional methods. See reference #3 below for the complete story.

And finally, do you know what Li-Fi is? It is a communication technology that uses light signals for communication instead of the radio waves in Wi-Fi. It has been around for some years, but is not very well known yet. The advantage with Li-Fi is that it permits very high transmission speeds. Very likely, you will see it around some time soon. In the meantime, look at reference #4 below.

… That’s what I learned in school !


1: The value of international scientific collaborations

2: Learn contemporary astrophysics from the leaders in the field

3: UW engineers achieve Wi-Fi at 10,000 times lower power

4: Li-Fi

+: What did you learn in school today ?

2016-02-24 (Wednesday)

These last days, I learned up front that patience is a virtue!

And now over to something totally different:


Photo taken by Dina Videman 2016-02-22


Tell me, what do the photo, so gracefully taken by my  friend Dina, and the mathematical formula above have in common ?

I will give you one hint, read the formula this way:

A dozen, a gross, and a score
Plus three times the square root of four
Divided by seven
Plus five times eleven
Is nine squared and not a bit more

Think well, have you heard that style of poetry before?

Now imagine that you are reading this poetry aloud while standing in the position of the photo.

That’s right, you are performing a limerick in Limerick!

A limerick is a form of poetry, especially one in five-line, predominantly anapestic meter with a strict rhyme scheme (AABBA), which is sometimes obscene with humorous intent. The third and fourth lines are usually shorter than the other three. It was popularized by the Edward Lear in the 19th century.

In reference #1 there is a good collection of limericks, but further to them here are some new ones that I  wrote today:

New Swedish limericks

De följande två limerickarna tillägnar jag mina spelkompisar på Wordfeud. Jag är säker på att de känner igen sig:

Det bor en kvinna i Timrå
I konståkning har hon sitt skrå
Hon syr vadderade uniformer
Helt enligt alla normer
Så att åkarna ej slår sig gula och blå

Det finns en man i Haväng
Som i skogen tar sig en sväng
Bland rödvita skärmar
Och kartor i pärmar
Han orientar och samlar poäng


Orientering i Borås djurpark 2015. Foto taget av Harald Persson, “mannen i Haväng”.

New Brazilian limerick

Gloria, uma raposa de Belo Horizonte
Colecionou camisas azuis de monte
Até que um dia
Ela entrou numa fria
E se jogou com as camisas da ponte


Uma amiga da Gloria

… That’s what I learned in school ! … Slut för idag, tack för idag ! … Por hoje é só !


1: Limerick

+: What did you learn in school today ?

2016-02-21 (Sunday)

Today, I learned once more that:

One of the most abstract things in our world is also something that we rely on the most. I am thinking about the so-called fourth dimension, time. Due to the earth’s rotation around its own axis, the world has been divided into 24 time zones, with the meridian that crosses the Greenwich observatory in England used as a starting point for the division, and thus establishing Greenwich Mean Time (GMT), nowadays mostly named Coordinated Universal Time (UTC).

Due to its subcontinental size, Brazil has four different time zones, which are related to the official Brazilian time in the Federal capital of Brasília. The following times apply as standard times:

  • Brasília time – 2 h (UTC-5 h): State of Acre, and the Southwestern part of the state of Amazonas. The proportion of people living here is only 0,5 % of the country’s whole population (a little more than 1 million people). This time zone covers only about 6% of the Brazilian territory (although it is about the size of France).
  • Brasília time – 1 h (UTC-4 h): States of Mato Grosso, Mato Grosso do Sul, Rondônia, Roraima, and the rest (main part) of Amazonas. 5% of the country’s population live here (about 11 million people). The area is big, 34% of the land area of Brazil (thus larger than Argentina).
  • Brasília time, BRT (UTC-3 h): Federal District (which includes Brasília); and also the states in the Southeast Region ( Espírito Santo, Minas Gerais, Rio de Janeiro, and São Paulo); the South Region ( Paraná, Rio Grande do Sul Santa Catarina, and Rio Grande do Sul); and the Northeast Region ( Alagoas, Bahia, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, and Sergipe) as well as the states of Amapá, Goiás, Pará, and Tocantins. Almost 94% of the whole Brazilian population live in this time zone, which also covers about 60% of the country’s land area.
  • Brasília time + 1 h (UTC-2 h): A few small offshore Atlantic islands, namely Fernando de Noronha, with 2,837 inhabitants and 0,0014% of Brazil’s population, an the non-populated islands of Trindade, Martim Vaz, Rocas Atoll, and Saint Peter and Saint Paul Archipelago.

The reason I am mentioning this today is that yesterday at midnight in Brasília, some of the states mentioned above, namely the Federal District and the 10 Southernmost states (Rio Grande do Sul, Santa Catarina, Paraná, Mato Grosso do Sul, São Paulo, Rio de Janeiro, Espírito Santo, Minas Gerais, Goiás, and Mato Grosso) ended the period of Daylight Savings Time (DST), also called Summer Time, that had been valid since October 18, 2015. The population in those areas account for 64 % of the total Brazilian population.

DST was used in Brazil for the first time in 1931, but from then on there was no consistency in when it was applied. It was only in 1985 that DST was instituted and followed on a regular, annual base, normally between the third Sunday of October and the third Sunday of February the subsequent year. However, Carnival and general elections have influenced on different start and end dates on some occasions.

One interesting observation that can be made is that the change always happens around midnight Brasília time, which creates a big confusion about which day it is at a given time. To me, the European rule of making the change at 02:00 / 03:00 seems much more logical.

However, there are people that oppose to the use of DST. As an example, there are currently three different propositions in the Brazilian Congress that want to forbid the use of DST. One of those propositions was written by congress man Valdir Colatto from Santa Catarina. Here are his arguments:

  • An institute of cardiology performed scientific tests about how DST affects the people, and they found an increase in health problems, from hypertension to diabetes, sometimes also depression.
  • During DST, the children learn less in school, because they have to wake up earlier.
  • He normally needs to wake up at 04:30 on Monday mornings, so that he can take a plane from his home town, Chapecó, to Brasília an hour later. During DST, he has to wake up at 03:30 solar time, an hour earlier due to a decree from the President of the Republic.
  • He responds to the official argument, that the use of DST saves energy, that nobody notes that difference in their electricity bill.
  • According to him, a survey performed on the internet resulted in that 80 % of those that responded to the survey said that they were against the use of DST.


Solution to Riddle # 1 (Two blind men), posted on 2016-02-19

When the socks are sold in the store, they are also grouped together in pairs. Thus, it is easy to grab one pair, separate the socks and place one each in each of the two men’s bags. Continue doing so, and eventually you will have two blue socks, two red socks, two pink socks, two green socks, and two orange socks in each bag.

I have already told this riddle to many people, but only one person could ever solve it, and it took only 15 seconds! This is a tribute to my good old friend, the chemist John Snyder, one of the most intelligent people I know!

The riddle was first proposed by Kim Nasmyth, Professor of Biochemistry at the University of Oxford, to explain how chromosomes divide in cell division, see reference # 3 below.

Riddle # 2 (The pill roulette)

You suffer from a temporary disease, which you have to treat by taking one pill every day during seven days. So the pharmacist took your order and gave you the pills. You are just about to take the first pill, when you receive a telephone call from the pharmacy.

You are informed, that the attendent mistakingly gave you eight pills, the seven you need and also an eighth one, that has the same appearance as the other. But it is poisonous and furthermore it weighs a little bit more than each of the other seven, undetectable by assessing it in your hand, but sufficient to be determined by a precision scale.

Luckily, you are in a laboratory which has such a scale, an old analogue weighing scale with two pans for high precision weight measurement. The problem is that you will only be able to perform two measurements, after which the scales will not work any more.
Here is a drawing of the scales you can use:


A two-pan balance scale to be used in riddle # 2

So how do you solve this riddle, to identify and discard the poisonous pill, with only two comparative measurements? A solution to this riddle will be published next Saturday, 2016-02-27. The first person that comes across the correct solution and sends it to medieborgaren@sjson.com will receive an honorary mention.

… That’s what I learned in school !


1: Time in Brazil

2: Horário de verão acaba à meia-noite deste sábado

3: How chromosomes split in cell division

+: What did you learn in school today ?

2016-02-20 (Saturday)

Today, I learned that:

Scientists at the Optoelectronics Research Centre of the University of Southampton, on England’s Southern coast, have made a major step forward in the development of digital data storage that is capable of surviving for billions of years. Using nanostructured glass, they have developed the recording and retrieval processes of five dimensional (5D) digital data by femtosecond laser writing.
The storage allows unprecedented properties including 360 TB/disc data capacity, thermal stability up to 1000 °C and virtually unlimited lifetime at room temperature (13,8 billion years at 190 °C ) opening a new era of eternal data archiving. This very stable and safe form of portable memory, could be highly used to store massive quantities of information, such as those found in national archives, museums and libraries.


Two examples of eternal 5D storage, King James Bible and the Universal Declaration of Human Rights. Copyright and photos by the University of Southampton 2016

In 2013, they demonstrated a 300 kbyte digital copy of a text file recorded in 5D, and now other documents such as the Universal Declaration of Human Rights (UDHR), Newton’s Opticks, Magna Carta and Kings James Bible, have also been saved.
Further information about this amazing storage technology can be found in reference # 1, below.

That’s what I learned in school !


1: Eternal 5D data storage could record the history of humankind

+: What did you learn in school today ?