Showing posts with label mathematics. Show all posts
Showing posts with label mathematics. Show all posts

Wednesday, July 26, 2023

Currency Today : Azerbaijan 6

50 manat note:

The fifth note in the current series of banknotes of Azerbaijan, is the 50 manat-note.
This note is dedicated to science and education. Again, two versions are in circulation.

50 manat - old style

In the 'old style' note, we see again the gap in the left and right border frame. Again this gap is larger than in the lower denomination.
We see two students and a teacher left of the staircase on the 1st version.

50 manat - new style
The renewed version has lines in the gap, meanwhile 9 (/).
Now we see 3 students and the teacher, (or is it a 'manat'-work?) and in the security thread, another student/teacher.
When you tilt the banknote, the golden security mark of the man becomes a moving object.
We see the man walking forward.


security thread 50 manat


security thread - walking man
Also the 5th coin shows a similar design.

20 qəpik
The 20 qəpik coin shows a spiral staircase, and mathematical symbols.
There is also a part of a pentagon, and an inscribed circle. This symbol only returns on the old style note.

detail of the 'old' 50 manat  note
to be continued ...

Monday, September 24, 2018

Currency Today : Denmark 3

Next on the list on danish banknotes, is a 200 DKK-note.

The front side shows us a bridge once more. The bridge in the image is the Knippel's Bridge
"Knippelsbro" is a bascule bridge across the Inner Harbour of Copenhagen, Denmark, connecting Børsgade on Zealand-side Slotsholmen to Torvegade on Christianshavn.
200 BKK (€ 27)
The history of the bridge dates back to 1620! After several wooden bridges, the current bridge (the sixth one), was originally known as Store Amager Bro (English: Great Amager Bridge) or Langebro (English: Long Bridge).
Knippelsbro by Janus Ridter
From around 1700 Christianshavns Bro (English: Christianshavn's Bridge) is seen. The current name stems from Hans Knip who became bridge caretaker in 1641, in charge of operating the bridge and collecting tolls from passing ships. His house became known as Knippenshus and during the 17th century the bridge became known as Knippensbro. And although this last name was never adapted officially, the bridge is known as the Knippel's bridge now.

Knippelsbro now
Further on the front side of the note, we see a holograpic image of a shield. As the image is not that clear, we have to look on the reverse side of the banknote, to see what it is about.
holograpic image of a shield - 200 DKK
It is an image of the Langstrup belt plate, a piece of decoration from the early Bronze Age (1400 BC).
Langstrup Belt Plate - 200 DKK
The Langstrup belt plate was found before 1880 together with a bronze knife and spiral
bangles. The decoration is composed by circular grooves and spirals, stamped probably by means of some standard punches into wax model before casting. Belt plates were worn by women on the front of their belts.
A detail of the decoration
The numbers are the turns of the spiral, counted at two different radial directions. The roman number gives the corresponding annulus. 
"It has, apart from the point, four zones with 15+22+26+32 = 95 spirals in all. Still, a numerical pattern does not seem to emerge. However, if one … multiplies by the number of the factor of the zones, the sum of the spirals turns out to be 15×1+22×2+26×3+32×4 = 265, or exactly the number of days in 9 months of the Moon-year (265½), or, incidentally, also the length of the average human period of pregnancy... 
Going one step further, and again multiplying with the zonal factors, but now incorporating the point of the Langstrup belt-plate as Factor 1 (but with the value of 0), a sum of 0×1+15×2+22×3+26×4+32×5 = 360 appears." 


reverse side of 200 DKK

Location of the Knippelsbro and the Langstrup belt-plate
More to follow ...

Saturday, September 22, 2018

Currency Today : Denmark 1

Not all countries in Europe are using EURO as their currency.
So isn't Deenmark, which is located in the north of Germany (only land border), between the North Sea and the East Sea. It's connected to Sweden by a brigde (see my article on Swedish currency).
Denmark itself is the smallest of the Scandinavian countries, but it forms the Kingdom of Denmark, together with Greenland and the Faroe Island, who are autonomous constituent countries.

The current set of banknotes (issued in 2009) are 50, 100, 200, 500 and 1000 kroner (crowns).

The first note is already something special : the 50 koner-note...
front side of 50 DKK (€ 6,75)
On the front side of the 50 kroner-note, we see a detail of the Sallingsund Bridge. With 1.717 meters, the  Sallingsund Bridge (Danish: Sallingsundbroen) connects the island of Mors with the peninsula of Salling, in the north western part of Denmark. It is the fifth longest bridge in Denmark.
Sallingsund Bridge
The hologram on the front, returns in de picture on the reverse side of the note.
hologram
Skarpsalling vessel (clay)
It represents the Skarpsalling Vessel (a clay vase or pot) found in east side of Denmark.
On the map, on the banknote, both bridge and vase are located.
map of Denmark (white parts) with location of bridge and vase

reverse side of the banknote 50 DKK
There is something more about the banknote, that you might not have remarked at first sight.

First thing in Danish language, is that they use some archaic constructions for numbers.

1,5 halvanden half-second
2,5 halvtredje half-third
3,5 halvfjerde half-fourth
4,5 halvfemte half-fifth

It's also known in Dutch language, when talking about time : half twee (half-two) is 1:30 or half past one; half drie (half-three) is 2:30 (half past two) and so on...

Secondly, Danish numbering is 20-based and not 10-based.
Compare to the French, Swiss, french speaking Belgians .... 80 is quatre-vingt (4 times 20).
Although also 'octante' or even 'huitante' is used in Switzerland...

Same for the Danish counting. But how about 50 ...  well since 50 is 2,5 times 20,
the counting goes : 2,5 (half-third) times 20 = 50.
In stead of  'femti' (5 x 10) is 50, it became "2,5 times twenty" or halvtreds(ind-s-tyve)

To be complete : the multiples of ten, above 50 - should be considered as multiples of 20, and the 'multiplier' is one half away from the higher integer...

The base 20 numeral system is also called the vigesimal system.

50 halv-tred-s(ind-s-tyve) half-third-t(imes-of-twenty)
60 tre-s(ind-s-tyve) three-t(imes-of-twenty)
70 halv-fjerd-s(ind-s-tyve) half-fourth-t(imes-of-twenty)
80 fir-s(ind-s-tyve) four-t(imes-of-twenty)
90 halv-fem-s(ind-s-tyve) half-fifth-t(imes-of-twenty)

more to follow...