2019-05-31 (Friday)

Today, I learned that:

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.

The image of a black hole captured by the Event Horizon Telescope. Photo by the EHT Collaboration team, consisting of 200 astronomers at eight different telescope sites.

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.

3. Baarle

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.)

Andreas Liljeheden posing on a selfie in Baarle, in a street where both the Dutch and Belgian flags are blowing in the wind side by side.

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, …)

That’s what I learned in school !

Refs.:

1: Black hole picture captured for first time in space breakthrough

2: Vårdagjämning, fullmåne och ovanligt sen påsk: därför ser almanackan underlig ut 2019

3: Baarle

4: Andreas Liljeheden om ett avgörande EU-val

5: 45 Amazing World Maps

*: What did you learn in school today ?

2019-03-05 (É carnaval!)

Today, I learned that:

As you probably have heard, one of the most important events during the year in Brazil is to commemorate carnival. For a complete description of what carnival is, I recommend that you consult reference #1 below.

The most important day during carnival is always on the final Tuesday, and this year it occurs very late, March 5. Normally it is in February, but from time to time it can be in March. I thought that March 5 would be the latest possible date for carnival Tuesday, but in order to be sure, I consulted an authority in the matter, a well known German-Swedish meteorologist named André Franke. If you live in Sweden, then you have probably seen and heard him on the weather forecasts. Here is what he told me:

Carnival Tuesday occurs 47 days before Easter Sunday and thus varies in the same way as Easter. This year Easter Sunday is April 21 and as consequence, Carnival Tuesday is on March 5. Next time this will happen is in year 2030.

However, the latest date that Easter Sunday can occur is on April 25, which will happen in year 2038. Carnival Tuesday will then be on March 9, 2038. Recently, in year 2011, it almost happened, Easter Sunday was on April 24 and Carnival Tuesday on March 8. All this is due to when the March Equinox occurs. Easter Sunday is the first Sunday after the first full moon on or after the March Equinox.

The Equinox, which is a point in time, can occur on different dates on different places of the Earth, due to the time zones, but Easter Sunday is on the same date all over the globe, and as a consequence also the Carnival Tuesday.

André also has his blog, see reference #2 below, where he details various astronomical facts occurring over the year. If that sounds interesting to you, then I definitely recommend that you look it up, it is well worth it!

The periodic table 150 years

Anyone who remembers their Chemistry lessons will surely also remember the periodic table. This table is an elegant composition of the different elements present in our universe. It was proposed by the Russian chemist Dmitri Mendeleev and first presented to the world on March 6, 1869.

Thanks to his way of organising the elements in a systematic manner, many new elements which only appeared as blanks in his original table were soon discovered and his forecasts about their properties were surprisingly exact. See also reference #3 below.

That’s what I learned in school !

Refs.:

1: Carnival

2: Astroinfo.se

3: Dmitri Mendeleev

*: What did you learn in school today ?