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Benvenuti in queste pagine dedicate a scienza ed arte. Amelia Carolina Sparavigna

Saturday, June 16, 2018

Wardrobe of Curiosities





Domenico Remps (1620–1699): Cabinet of Curiosities  wikidata:Q19939108 
Current location Opificio delle pietre dure , Firenze

The monk, the polyhedrons and the wardrobe




Fra Giovanni da Verona. Tarsia raffigurante un armadio con poliedri. Courtesy Laurom di Wikipedia in italiano. 

Fra Giovanni da Verona (1457 circa – 1525) è stato un intarsiatore, miniatore, scultore nonché architetto italiano, attivo tra la fine del XV secolo e l'inizio del XVI secolo. Artista poliedrico, è ricordato in particolare per la maestria nell'intarsio e nella prospettiva.

Sfere cinesi (puzzle spheres)



Sfera cinese, in avorio, fatta di diverse sfere concentriche (British Museum. Original photograph from Ged Carroll)


Wikipedia dice che questo tipo di lavori è diventato popolare in Europa grazie alla produzione Cinese del XIX secolo. Ma la creazione di questi rompicapo ha origini ben più lontane. Antikitera.net ci informa che i primi esemplari fecero la loro comparsa durante la Dinastia Song, intorno all'anno 1000 d.C.

Pierre MEYER and the puzzle dodecahedron



Pierre Meyer is an artist who works with ivory.

A puzzle ball




Puzzle ball. This image is a courtesy of   " The Puzzle Museum http://puzzlemuseum.org". 

Chinese and European ivory puzzle balls

"By the 18th century China had a considerable market in items such as figures made for export to Europe, and from the Meiji Period Japan followed. Japanese ivory for the domestic market had traditionally mostly been small objects such as netsuke, for which ivory was used from the 17th century, or little inlays for sword-fittings and the like, but in the later 19th century, using African ivory, pieces became as large as the material would allow, and carved with virtuosic skill. A speciality was round puzzle balls of openwork that contained a series of smaller balls, freely rotating, inside them, a tribute to the patience of Asian craftsmen."

Usually, many of these balls have a decorated stand made of ivory too.



Chinese puzzle ball, with openwork and a series of twelve smaller balls, ivory, 19th century. British Museum. Original photograph from Ged Carroll

"Originally, they (Chinese puzzle balls) were made almost exclusively from ivory, or the tusks of elephants and were the playthings of rich men because of the time and effort involved in making them. ... Usually, puzzle balls are symbols of good luck, and are decorated with a variety of feng shui symbols. The outermost layer often features the phoenix and dragon, symbols of yin and yang. The phoenix represents the wife while the dragon is the husband and emperor, and balls decorated with these symbols are thought to bring good luck and happiness to a marriage. In fact, almost all of the symbols most commonly associated with puzzle balls are associated with ensuring a long and happy marriage. Some balls even have different symbols on different layers, though the most common is a highly decorative outer ball and ‘latticed’ balls inside (with geometric patterns of holes)."



Detail of an ivory ball on show in the German Rautenstrauch-Joest Museum. It has 16 layers, which can spin. Courtesy Till Niermann , Wikipedia.


In the above image we see an example of Canton ivory carving. From Wikipedia (on the Lingnan culture or Cantonese culture). "Canton ivory woodcarving is another well-known product from Lingnan. With a history of 2000 years, it traditionally uses ivory as raw material to make sculptures, with the Canton-style renowned for being particularly delicate and detailed without being brittle. The Cantonese people have also successfully produced the legendary craft product - Ivory ball. After the 1980s, however, international ivory trade has been banned. This results in the Cantonese people now trying to find substitute materials - materials that look and feel like but are actually not ivory - in their attempt to pass on this ancient art."

"Chinese puzzle balls are ornate decorative items that consist of several concentric spheres, each of which rotates freely, carved from the same piece of material. ... These detailed works of art are usually made up of at least 3 to 7 layers, but the world’s largest puzzle ball is actually made of 42 concentric balls all enclosed one within the other. Although the inner balls can be manipulated to align all the holes, Chinese puzzle balls got their name from people who, through the ages, pondered the mystery of making such objects. So how exactly are puzzle balls made? .... Chinese masters rotate a solid ball on a lathe and start by drilling holes toward the center of the objects. Then, using special “L”-shaped tools, they begin to separate the innermost balls. ...  Because it is easier to work with, the exterior shell is the most elaborately carved, usually featuring an intertwined dragon and a phoenix."

Antikitera.net tells us that the first puzzle balls appeared during the Song Dynasty, around 1000 d.C.
http://www.antikitera.net/news.asp?ID=11753

After having shown the Chinese ivory balls, it seems that the puzzle balls became popular in Europe thanks to Chinese products of the later XIXth century. However, puzzle balls existed in Europe in XVI or XVII century. Here an example.



European puzzle ball, XVI-XVII Century (Image Courtesy: Maureen and Renato Bucci, Italy). It was exhibited with a rosary having the beads made in the same manner of the ball. 



The rosary, XVI-XVII Century (Image Courtesy: Maureen and Renato Bucci, Italy).  


The ball shown in the image is remarkable because it looks like a Roman Dodecahedron. Actually Renato Bucci was so kind to send me the picture because of this similarity. Probably, this was an object of a Wunderkammer (in italiano, camera delle meraviglie o gabinetto delle curiosità o delle meraviglie), encyclopedic collections of objects of the Reinassance Europe.  


"The Kunstkammer was regarded as a microcosm or theater of the world, and a memory theater. The Kunstkammer conveyed symbolically the patron's control of the world through its indoor, microscopic reproduction."


An example of Kunstkammer
http://wonder-cabinet.sites.gettysburg.edu/2017/cabinet/carved-ivory-puzzle-balls/


Besides the balls, we have also the polyhedra. Here the dodecahedra created by Egidius Lobenigk (1581 - 1584). From https://artsandculture.google.com/entity/m0t50361?categoryid=artist we can see them. 



These dodecahedra are at Staatliche Kunstsammlungen Dresden, (courtesy image from Jürgen Karpinski, photographer).

Let me conclude remarking that today puzzle balls are created too. Here the image of one of them, which is showing a contempoary "puzzle dodecahedra". The artist that created it is Pierre Meyer is an artist who works with ivory. https://www.maitresdart.com/pierre_meyer-40/parcours_et_realisations.html



Pierre Meyer's ivory "puzzle dodecahedron".


Also "new production of ornamental turning ivory of '600" is evidenced by the works of Andrea Pacciani, architect in Parma, by the web https://www.etsy.com/it/listing/225172225/tornitura-ornamentale-da-un-modello-in. A piece "is inspired by a piece of the museum's collection of Rosenborg in Denmark (*). Another piece is inspiered to the drawings of Grollier de Serviere, (1596–1689), French inventor and ornamental turner.
According to Andrea, "Thanks to the new generation of 3D technologies we could bring back the light of contemporary production about this object collection of great visual impact". That is, new technologies for creating objecs for our modern Wunderkammer.


(*) the reader can see the pieces at http://www.bobkatsjaunt.com/denmark.html.





A drawing from a book on the works of  Grollier de Serviere

Friday, June 15, 2018

La fragole di Sophia

Ho trovato questo articolo, molto bello.

Sofia e la scoperta delle fragole, di Marco Bersanelli
"Il valore dell'ipotesi positiva nella ricerca scientifica. L'imprevisto, un avvenimento che porta a una novità irriducibile al già noto. L'adeguatezza della realtà all'io"
http://diesselombardia.vigevano.biz/imgdb/Scopertascientifica1997.pdf

Sunday, May 13, 2018

I Menhir di Sorgono (Biru e Concas) e le stelle

 Fig.1

Nel cuore della Sardegna, quasi al suo centro geografico (Fig.1), si trovano i menhir di Biru 'e Concas. L'importante sito archeologico è situato nel territorio del comune di Sorgono, in provincia di Nuoro. Wikipedia ci dice che il sito, che sorge su una collina, era probabilmente dedicato ad antenati defunti, diventati eroi della popolazione locale. Il sito risale ad un periodo compreso tra il Neolitico Recente (3300-2700 a.C.) e l'Eneolitico (2700-1700). I menhir si trovano disposti in molti modi, anche in allineamenti. Alcuni menhir presentano delle forme antropomorfe, e sono quindi definiti come statue stele. In Sardegna, le statue stele vengono datate intorno al III millennio a.C. (età del rame) e si possono suddividere in due tipi figurativi: un tipo maschile, che probabilmente rappresentava eroi o guerrieri mitici, ed un tipo con attributi femminili. 


Fig.2: Un allineamento del sito di Biru e Concas (Cortesia, Alberto Zilaghe, Street View, Google Earth)

Del sito di Biru 'e Concas, un articolo di Antonella Petris su meteoweb.eu riporta quanto segue. "Come spiega Corrado Mascia, un lettore di Meteoweb che di recente ha avuto modo di osservarli, “la concentrazione dei menhir è straordinaria ...  Sono disposti in coppia, isolati o in triadi secondo allineamenti circolari estesi che possono comprendere fino a venti menhir. Consistono, dunque, in un complesso di allineamenti megalitici, che secondo un filone culturale di studiosi, costituivano le carte astronomiche (o osservatori astronomici)determinanti il tempo e lo spazio e capaci di segnare i solstizi e gli equinozi". 


Fig.3: Ecco un notevole allineamento di 20 menhir. Seguono la direzione cardinale Nord-Sud.
In figura (Cortesia, SunCalc.org) si vedono le direzioni del sorgere del sole e del tramonto all'equinozio, secondo un orizzonte astronomico. L'allineamento di menhir è coincidente con la direzione meridiana.

Fig.4: Un altro allineamento di menhir (deviazione di circa 10 gradi dalla direzione cardinale verso Sud).


Consideriamo  il primo allineamento di menhir, quello che ha la direzione Nord-Sud. Se  guardiamo  verso Sud,  utilizzando Google Earth e il suo strumento che permette di avere il profilo di elevazione locale, vediamo che l'orizzonte naturale si eleva di circa 4 o 5 gradi sopra l'orizzonte astronomico. 
Che stelle potevano vedere le persone che avevano costruito il sito?
Usiamo il software Stellarium, che ci permette di simulare il cielo antico (Fig.5 e 6).


Fig.5: Ecco le stelle che si potevano vedere guardando verso Sud attorno al 3300 BC. Sopra l'orizzonte naturale, rappresentato dalla linea arancione, splende la Croce del Sud. Anche Alpha Centauri (Rigil Kentaurus) è visibile. La linea bianca rappresenta l'orizzonte astronomico.


Fig.6: Per effetto della precessione dell'asse terreste, attorno al 1700 BC, le stelle della Croce sono più basse sull'orizzonte naturale. 

Guardando la Fig.6, ci possiamo chiedere: Rigil Kentaurus era visibile sopra l'orizzonte naturale? Ed eventualmente, in che direzione sorgeva? Proviamo a simulare come si poteva vedere sorgere Rigil Kentaurus al sito di Sorgono (Fig.7). 

 Fig.7

Sempre con Stellarium, abbiamo che Rigil Kent arrivava a circa 4 gradi sull'orizzonte astronomico, e quindi poteva esser vista sorgere dall'orizzonte naturale, quanto il suo azimuth era di 10 gradi circa rispetto al Sud. Ma questo angolo è proprio l'angolo del secondo allineamento, quello mostrato nella Fig.4. 

In effetti, quanto detto dall'articolo di meteoweb.eu è ben fondato. Sarebbe interessante aver a disposizione altri articoli che mostrino anche gli allineamenti dei menhir, oltre a quelli che si vedono nelle'immagini satellitari, per poter fare altre simulazioni e conseguenti paragoni con le mappe stellari.






Processing images from Mars

A site exists which is giving processing of images from Curiosity.
It is https://www.facebook.com/JourneytotheSurfaceoftheMARS/
Here an example:
https://www.facebook.com/JourneytotheSurfaceoftheMARS/photos/a.333231393552422.1073741828.333200476888847/679750542233837/?type=3&theater

This link is showing a detail of the image (Courtesy: NASA)
https://mars.jpl.nasa.gov/msl-raw-images/msss/01692/mhli/1692MH0007060010603983C00_DXXX.jpg
Here the "object" we can see in it.


Thursday, May 3, 2018

Shell

The original image is available at the link
NASA's Mars rover Curiosity acquired this image using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover's robotic arm, on January 7, 2018, Sol 1927 of the Mars Science Laboratory Mission, at 06:40:59 UTC.
Image Credit: NASA/JPL-Caltech/MSSS 

Some processing of the image is giving this "shell".


Mimetic "animal"

The original image is available at the link
The image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 1928 (2018-01-08 04:04:28 UTC). Image Credit: NASA/JPL-Caltech/MSSS 

Some processing of the image is giving this mimetic "animal".


Wednesday, April 4, 2018

Astronomical Analysis of Diagonal Avenues of Washington


An Astronomical Analysis of Some of the Diagonal Avenues of Washington
PHILICA, 2016,Article 613 Available at SSRN
 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2789700

Amelia Carolina Sparavigna

Here we are proposing an astronomical analysis of the directions of some of the diagonal avenues of Washington, made by means of satellite images and a modern ephemeris, the Photographer’s Ephemeris, a well-known software used for planning outdoor photography. Some diagonal streets of Washington seem had been aligned along the northern moonrise azimuth of 1791, the year the engineer Pierre Charles L’Enfant started the survey for planning the town for George Washington, and along the southern moonrise azimuths of 1792, the year the surveyor Andrew Ellicott revised the plan. In this manner, in the directions of some diagonal avenues, the engineers that worked on the urban project, introduced a reference to the years of their plans for the Capital of the United States.
Keywords: Astronomy, Satellite Images, Architecture, Modern Ephemerides, Urban Planning


 Copy of the U.S. Coast and Geodetic Survey, Washington, D.C. (1887).

Detail of Figure 1, with some diagonal avenues of L’Enfant Plan and angles.

A detail of the faint original map of 1791 (https://www.loc.gov/item/88694205/) after a processing of the image.

Google map of Washington.

Snapshot of the Photographer s Ephemeris for Washington on October 3, 2015.  The blue lines are the moonrise and moonset azimuths, the yellow and orange lines those of sunrise and sunset. Note the coincidence to the diagonal avenues.

Snapshot of the Photographer s Ephemeris for Washington on October 3, 2015. 

  
Snapshot of the Photographer s Ephemeris for Washington on October 18, 2015.  

Shwedagon Pagoda and the Zenith Passage of the Sun on Vesak Day of Buddha

An article discusses the orientation of the Shwedagon Pagoda, the gilded stupa situated on Singuttara Hill in Yangon, Myanmar, and a possible link with the sunrise on the days of the zenith passage of the sun. These days are also linked to the Festival of the Full Moon of the month of Kason, the second month of the traditional Burmese calendar. In Myanmar, this is the festival of the Vesak Day of Buddha.

 PHILICA, 2018, Article number 1233.


The south-eastern side of Shwedagon Pagoda. Image Courtesy: Bjørn Christian Tørrissen


A monk is walking on the facade. Image Courtesy: Bjørn Christian Tørrissen.



Sunrise direction on the day of the Kason Festival, 29 April 2018 (Courtesy SunCalc.org).

Image Segmentation - Phloem and Xylem


Measuring the size of tubules in phloem and xylem of plants 
Philica,  2017, n.1104.The paper is showing how to measure, by means of the segmentation of a SEM image, the cross-sections of the tubules in phloem and xylem of plants. https://hal.archives-ouvertes.fr/hal-01578826