that is, ideas and information on Science and Technology, Archaeology, Arts and Literatures. Physics at http://physics-sparavigna.blogspot.com/
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Saturday, January 7, 2012
The Erbil Citadel
http://whc.unesco.org/en/tentativelists/5479/
Friday, January 6, 2012
Megalith Map
http://www.megalithic.co.uk/asb_mapsquare.php
Louisiana's wetlands
http://www.atlantisbolivia.org/canalslouisiana1.htm
Ohm's law at atomic scale
"A new technique for embedding atomic-scale wires within crystals of silicon has revealed that Ohm's law can hold true for wires just four atoms thick and one atom tall. The result comes as a surprise because conventional wisdom suggests that quantum effects should cause large deviations from Ohm's law for such tiny wires. Paradoxically, the researchers hope the finding will aid the development of quantum computers."
Thursday, January 5, 2012
Chimeras
More http://www.guardian.co.uk/science/2012/jan/05/chimera-monkeys-combining-several-embryos
Noah's problems
The tile is: THE NOAH’S ARK PROBLEM, by MARTIN L. WEITZMAN
Abstract: This paper is about the economic theory of biodiversity preservation. A cost-effectiveness methodology is constructed, which results in a particular formula that can be used as a criterion to rank projects. The ranking criterion is sufficiently operational to be useful in suggesting what to look at when determining actual conservation priorities among endangered species. At the same time, the formula is firmly rooted in a mathematically rigorous optimization framework, so that its theoretical underpinnings are clear. The underlying model, called the “Noah‘s Ark Problem,” is intended to be a kind of canonical form that hones down to its analytical essence the problem of best preserving diversity under a limited budget constraint.
Keywords: Biodiversity, endangered species, diversity theory
The author writes
"There are several motivations for this paper. Essentially, I am trying to introduce an analytical framework that represents a useful way of thinking about the economics of diversity through the medium of an abstract mathematical model. The “Noah’s Ark Problem” is a parable intended to be a kind of canonical form of the simplest possible way of representing how best to preserve biodiversity under a limited budget constraint. Throughout the paper, emphasis is laid upon simplicity of structure, in order to get at the analytical essence of
the problem."
Noah's-ark-problem-pdf
Wednesday, January 4, 2012
Aran Islands
Megalithic Ireland
http://www.irishmegaliths.org.uk/iremap.htm
For each county, there is the list of places and images. See for instance:
http://www.irishmegaliths.org.uk/galway.htm
A "Noah's ark" rock
Using the satellite maps, I was searching for any stone structure in the Ararat area, made by ancient men, as I did in Arabia and Syrian Desert [1,2], when I saw what looks like a huge rock structure, broken in two parts. This natural structure has a color and outline quite different from the surrounding area. Since it is on Ararat, let me call it the "Noah's ark" rock!
This is how you are to make it: the length of the ark 300 cubits,
its breadth 50 cubits, and its height 30 cubits.
To see some ancient man-made stone structures, please visit:
Stone structures in the Syrian Desert , http://www.archaeogate.org/vicino_oriente/article.php?id=1445
Tuesday, January 3, 2012
An Arctic solution to the data storage
"We generate a storm of data throughout the day, whether we want to or not ... And the amount of data we generate personally is dwarfed by the numbers generated by government, industry and commerce. All this data has to be stored and this is giving rise to a new form of building, characteristic to the early 21st century: the data centre. Sharing some of the form and characteristics of ages-old strongrooms and more modern hardened bunkers, these are the locations that keep the numbers vital to our lifestyles, and the fortunes of government and industry, safe. But this has also generated a set of problems for civil engineers. The most vital thing that a data centre has to do is to keep its ranks of computer servers running. For that, they need two things: power and cooling..."
Cloaking objects from surface water waves
http://physics.aps.org/articles/v5/2
"Cloaking devices made of a composite of soft and hard materials can divert elastic vibrational waves around an object as though it wasn’t there. Though cloaking devices are mainly associated with hiding objects from light, the concept of cloaking is not restricted to electromagnetic waves. Experimentalists have shown they can cloak objects from surface water waves [1] and electron waves on the surface of metals (plasmons) [2]. Now, Nicolas Stenger at the Karlsruhe Institute of Technology in Germany and his colleagues have designed and tested a cloak that makes an object in a flexible medium invisible to elastic vibrational waves [3]; that is, the waves pass by the object as though it wasn’t there. The work, which is presented in Physical Review Letters, describes a cloaking device that is both more efficient and covers a wider bandwidth than any other existing cloak."
Aristippus of Cyrene
BOOK THE SIXTH, INTRODUCTION.
ARISTIPPUS, the Socratic philosopher, shipwrecked on the coast of Rhodes, perceiving some geometrical diagrams thereon, is reported to have exclaimed to his companions, " Be of good courage, I see marks of civilization" and straightway making for the city of Rhodes, he arrived at the Gymnasium; where, disputing on philosophical subjects, he obtained such honours, that he not only provided for himself, but furnished clothing and food to his companions. When his companions had completed their arrangements for returning home, and asked what message he wished to send to his friends, he desired them to say that the possessions and provision to be made for children should be those which can be preserved in case of shipwreck; inasmuch as those things are the real supports of life which the chances of fortune, the changes of public affairs, and the devastation of war, cannot injure.
Monday, January 2, 2012
2011: The Year of Materials
The Year in Materials - Technology Review
Thursday, December 29, 2011
A mound near Jefferson City
http://www.jeffcitymo.org/main/historyheritage.html
Information on the mounds near Jefferson City we can find in the paper
published by The Project Gutenberg EBook of Scientific American Supplement, No. 841,
February 13, 1892, by Various
INVESTIGATION OF A MOUND NEAR JEFFERSON CITY, MO, By A.S. LOGAN.
Logan wrote
"Recently, a party consisting of engineers and employes of the Missouri River Improvement Commission began an exploration of one of the mounds, a work of a prehistoric race, situated on the bluff, which overlooks the Missouri River from an elevation of one hundred and fifty feet, located about six miles below Jefferson City.
This mound is one of about twenty embraced in a circle one quarter of a mile in diameter.
The above party selected the mound in question apparently at haphazard; all the mounds presenting nearly a uniform outline, differing only in size and mostly circular in form, and from twenty to twenty-four feet at the base, rising to a height of eight feet and under. A trench was cut on a level with the natural soil, penetrating the mound about eight feet. A stone wall was encountered which was built very substantially, making access in that direction difficult, in consequence of which the earth was removed from the top for the purpose of entering from that direction. The earth was removed for a depth of four feet, when the top of the wall was exposed. Further excavation brought to light human bones, some of them fairly well preserved, especially the bones of the legs. On the removal of these and a layer of clay, another layer of bones was exposed, but presenting a different appearance than the first, having evidently been burned or charred, a considerable quantity of charcoal being mixed with the bones. In this tier were found portions of several skulls, lying close together, as if they had been interred without regard to order. They were, in all probability, detached from the body when buried....
A few pieces of flint weapons were found in the upper layers, and nothing else of any significance....
At this juncture the diggers abandoned the search, and some days later the writer, desirous of seeing all that was to be seen, resumed the work and removed the earth and remains until the bottom of the vault was reached; several layers being thus removed. All of these had evidently been burned, as charcoal and ashes were mixed with the bones of each succeeding layer. The layers were about an inch in thickness, with from two to four inches of earth between, and small flat stones, about the size of a man's hand, spread on each different layer, as if to mark its division from the next above.
Between the bottom layers, mixed with charcoal, ashes and small portions of burned bones were found what gives value to the search, numbering about fifty tools and a smoking pipe.
The material of the tools is the same as the rock forming the vault, locally known as "cotton rock." I would consider it a species of sandstone.
Overlying the edge of "cotton rock" in the bluff is flint in great quantities, and in every conceivable shape, that these people could have resorted to had they been so disposed, and why they used the softer material I will leave to some archæologist to determine. The tools themselves are made after no pattern, but selected for their cutting qualities, as they all have a more or less keen edge which could be used for cutting purposes, and were no doubt highly prized, as they were found all in a pile in one corner of the vault and on top of which was found a stone pipe. The pipe is made bowl and stem together, and it is curious that people of such crude ideas of tools and weapons should manufacture such a perfect specimen of a pipe. It is composed of a very heavy stone, the nature of which would be difficult to determine, as it is considerably burned.
A description of the vault will be found interesting to many. The wall of the vault rests upon the natural surface of the ground, about three feet high and eight and a half feet square, the inside corners being slightly rounded; it is built in layers about four inches in thickness and varying in length upward to three feet, neither cement nor mortar being used in the joints; the corners formed a sort of recess as they were drawn inward to the top, in which many of the stones were found. The stone for constructing the vault was brought from a distance of about a quarter of a mile, as there is none in sight nearer.
I assume from all these circumstances that these people lived in this neighborhood anterior to the age of flint tools, as the more recent interments indicate that they were then entering upon the flint industry, and it may be that the "cotton rock" had become obsolete.
These people buried their dead on the highest ground, covering and protecting them with these great mounds, when it would seem much easier to bury as at the present day; but instead, they, with great labor, carried the rock from a great distance, and it is reasonable to suppose, also, that the earth was brought from a distance with which they are surrounded, and piled high above, as there is no trace of an immediate or local excavation....
My object is the hope of a more thorough investigation at some future time...."
Wednesday, December 28, 2011
Bicycles - 1897
In It, Vol. 1, No. 19, March 18, 1897, by Various
What a great thing this will be! Fancy wheeling away over the snow, propelling our wheels as fast as the pedals can make us go. The bicyclists ought to be very happy this year; so many clever brains are working for their comfort and pleasure. All who ride have been troubled at times what to do with the bicycles when they are standing still.
It may be there is damp grass, which would make it impossible to lay the precious wheel down; or there may be a thousand other little inconveniences. Some one has come to the aid of the bicyclist, and invented a bicycle support, which can be secured to the machine, and raised at will, so as not to interfere with the wheel when in motion. It is just the thing all bicyclists have been longing for.
Another busy brain has been at work in anticipation of the summer, and the glorious time in store, riding along the country roads. An umbrella support is the result. It consists of an attachment composed of portions which can be connected or removed at will. What a boon it will be, on a hot summer's day, to have an umbrella comfortably held over one's head, while the hands are free to guide the wheel!
The searchlight - 1897
In It, Vol. 1, No. 15, February 18, 1897, by Various
http://www.gutenberg.org/files/15325/15325-h/15325-h.htm
we find the following news
"INVENTION AND DISCOVERY.- 1897
A New York newspaper has been making some experiments in signalling ships at night, which, if as successful as it is claimed to be, will be of the greatest service to sailors for all time to come.
Ships have a regular way of talking to one another, by means of flags arranged in certain ways...
There has been one difficulty with the flag-signals, and that has been that they were useless at night. When it became too dark for the flags to be seen, sailors had no other means of communication.
The New York paper claims to have overcome this difficulty.
In saying that ships have no means of communicating with each other, it must not be forgotten that they can use lights and send certain messages with them. But the flag system enables them to say exactly what they wish to, while through the lights they can only show where they are, and call for help in case of accident.
The invention of the searchlight set men thinking, and at last the idea struck one man that if the searchlight were turned on the flags, it ought to be perfectly possible to see them in the darkest night.
A few nights ago two tugs went down to Sandy Hook to try if the experiment would work. To their great delight they found it did answer perfectly. The tugs were stationed about a mile and a half apart, and could read with ease the messages waved across the water.
More experiments will be made, and if on further trial the method is found to be practical, a great advance will have been made in navigation...
This invention is in the nature of a powerful foghorn. It is, however, made somewhat like a musical instrument, so that different tones can be produced by it; and the idea is to have these tones arranged into a signalling code, after the fashion of the flag-signals, so that a conversation can be kept up in a similar way to that done with flags. G.H.R."
Of course, the use of the Morse Code is better. But we have to wait till the Aldis Lamp.
According to the Oxford Dictionary: Aldis lamp, a handheld lamp for signalling in Morse code. Origin:
First World War: named after Arthur C. W. Aldis (1878–1953), its British inventor
The Aldis Lamp is a signal lamp, a visual signaling device for optical communication (typically using Morse code). Modern signal lamps are a focused lamp which can produce a pulse of light.
Moving sand dunes
The barchans move. Note the dunes on the tracks.
Centennial Superconductivity
Volume 51, Number 1, January 2012
had published the Special Section: Centennial Anniversary of Superconductivity in commemoration of the 50th anniversary of JJAP and the centennial anniversary of superconductivity.
Special Section —Centennial Anniversary of Superconductivity—
Comprehensive Review
Invited Review Papers
Selected Topics in Applied Physics
Rapid Communications
Regular Papers
Semiconductors, dielectrics, and organic materials
Photonics, quantum electronics, optics, and spectroscopy
Spintronics, superconductivity, and strongly correlated materials
Device physics
Nanoscale science and technology
Crystal growth, surfaces, interfaces, thin films, and bulk materials
Plasmas, applied atomic and molecular physics, and applied nuclear physics
Device processing, fabrication and measurement technologies, and instrumentation
Brief Notes
Tuesday, December 13, 2011
Higgs boson
One experiment, known as Atlas, suggested that the hypothesized Higgs is most likely to have a tiny mass, in the range of 116 to 130 gigaelectronvolts, or GeV. The other experiment pegged mass at 115 to 127 GeV. The experiments were carried out at the European particle physics laboratory CERN near Geneva."
http://online.wsj.com/article/SB10001424052970203430404577096330121408786.html
Wall Street Journal
Thursday, December 8, 2011
Acoustic freezer
More http://en.wikipedia.org/wiki/Thermoacoustic_heat_engine
Wednesday, December 7, 2011
Mollusc shell features in engineering materials
"The mollusc shell is made up of only one mineral: calcium carbonate, yet the combination of that plus other enzymes and proteins gives it remarkable properties in terms of strength, while remaining incredibly light. Prof Mark Rodger, project leader and director of Warwick University’s Centre for Scientific Computing, told The Engineer: ‘The whole point of this project is to try to understand what happens when you make hybrid materials that are partly organic and partly inorganic.’"
Read more: Mollusc shell features could be replicated in synthetic fabrics | News | The EngineerMonday, December 5, 2011
Hic sunt Garamantes
Archaeologists from the University of Leicester have used all this aerial data to identify as much as they can about the so-called Garamantes people, who are otherwise known purely through Greek and Roman sources. They've already discovered "the mud brick remains of the castle-like complexes, with walls still standing up to four metres high, along with traces of dwellings, cairn cemeteries, associated field systems, wells and sophisticated irrigation systems." "
http://io9.com/5857958/satellites-reveal-libyas-lost-2000+year+old-cities
Friday, December 2, 2011
Raphael's portrait of Leonardo
Abstract: In one of his paintings, the School of Athens, Raphael is depicting Leonardo da Vinci as the philosopher Plato. Some image processing tools can help us in comparing this portrait with two Leonardo’s portraits, considered as self-portraits.
There is a portrait in red chalk, dated approximately 1510 and held at the Biblioteca Reale of Turin, which is widely accepted as a self-portrait of Leonardo da Vinci. It is thought that Leonardo drew this self-portrait at the age of 58 or 60 (see Fig.2). Ref.5 tells that this well-known drawing is not universally accepted as a self-portrait, because the depicted face appears to be quite old, suggesting that Leonardo represented his father or grandfather. Another possibility is that Leonardo altered himself, in order that Raphael might use it for his Plato. However, Plato does not look so old in the painting by Raphael.
To use this portrait it is necessary to remove the written text. Carlo Pedretti was the first to suggest a “restoration” of this drawing, of course not of the real page of the Codex, but made on a photographic plate. It was only two years ago, in 2009, that Piero Angela, an Italian scientific journalist, presented the digital restoration of the portrait [8,9], that is, the restoration of the corresponding digital image. In 2009, I have proposed a simple approach that uses an iterative procedure based on thresholding and interpolation with nearest neighbouring pixels [10,11]. Recently, I proposed a further processing with a wavelet-filtering program, Iris [12-14]: the result is shown in Fig.3, right panel. According to Pedretti, this is the young Leonardo da Vinci self-portrait.
In Figure 5 we have the two images, the Raphael painting on the right and the result of merging the two Leonardo’s drawings on the left, shown side by side. Let me remark that we are looking at two images obtained from originals created by two artists who used different techniques and a different rendering of the head position. Moreover, there is another fact, which is in my opinion quite important, that the two portraits are showing a distinct side of the face. And we know very well that the two sides are not equal and that the existing small differences create the "good" and "bad" side of our faces [16].
Let us remember that for all the living creatures, the bilateral symmetry [17] of the body is an approximate symmetry: the two halves, left and right, of the body and then of the face, are not perfectly symmetrical. The symmetry of human faces is a subject of several studies. Some researchers are supporting the idea that more symmetry means more beauty and freedom from diseases [18-20]. On the other hand, a face, which is too symmetric, gives the impression of being unnatural [21].
I decided to change the Raphael’s image, with a reflection and a small rotation using GIMP. Moreover, I converted the colours in grey tones, to avoid the vision of different hues. Fig.7 gives the result. Is the figure showing the same person? I guess that there is this possibility, but further studies are necessary. Let me then avoid a direct answer and just write some conclusions.
References
Wednesday, November 23, 2011
A young Leonardo
Friday, November 18, 2011
Turning darkness into light
"Quantum mechanics tells us that the vacuum is not empty but is filled with virtual particles that pop into and out of existence. Normally these particles are hidden from our view, but now a team of physicists has used the electrical equivalent of an ultrafast mirror to convert virtual photons into real electromagnetic radiation. Known as the dynamical Casimir effect, it was first predicted more than 40 years ago. The static Casimir effect ... 1948, involves two perfectly reflecting parallel mirrors that, when placed in a vacuum, will be attracted to one another. This attractive force is caused by the radiation pressure exerted by virtual photons outside the mirrors and the fact that this pressure exceeds the pressure between the mirrors because of the limited number of modes of electromagnetic vibration that are permitted within this gap. In other words, the force results from a mismatch of electromagnetic modes in space. The dynamical effect was proposed by Gerald Moore in 1970 and is caused by a mismatch of modes in time. The phase of an electromagnetic wave goes to zero at the surface of a mirror, if that mirror is a perfect electrical conductor. When the mirror is moved slowly through a vacuum, this zero point can move with the mirror. However, if the mirror is moved at a significant fraction of the speed of light, then the electromagnetic field does not have time to adjust but instead becomes excited and as a result generates real photons. Put another way, the mirror prises virtual photons (always produced in pairs) apart so that instead of rapidly annihilating, the particles are free to remain as real photons."
Thursday, November 17, 2011
Earth's close encounter of asteroids
Should Earth's close encounter trigger asteroid avoidance research? | Opinion | The Engineer
Tuesday, November 15, 2011
Leonardo, Genio e Mito
http://www.lavenaria.it/mostre/ita/mostre/archivio/2011/leonardo.shtml
In esposizione vi è l'autoritratto della Biblioteca Reale e il Codice del Volo.
In una pagina del codice, sotto la scrittora di Leonardo, vi è un ritratto, forse un suo autoritratto da giovane.
Vedi http://staff.polito.it/amelia.sparavigna/da-vinci-portrait.html
Tuesday, November 8, 2011
Bee rescue
http://www.abc.net.au/science/articles/2003/05/08/2045526.htm#artBookmarks
"Of the 1600 species of wild bees native to Australia, about 14 species are stingless. As stingless bees are harmless to humans, they have become an increasingly attractive addition to the suburban backyard or verandah.
Most stingless bee keepers are not after honey. Rather, they enjoy the sense of conserving a native species whose original habitat is being increasingly cleared and developed. In return, the bees pollinate crops, garden flowers and bushland during their search for nectar and pollen."
Stingless bees
http://en.wikipedia.org/wiki/Stingless_bee
¿Un Futuro Sin Abejas?
Especial Abejas: ¿Un Futuro Sin Abejas?
Thursday, October 27, 2011
Giant Waterworld Around Naked Eye Star
"55 Cancri A is a Sun-like star some 40 light years away. It has an apparent magnitude of about 6 and so is visible to the naked eye in the constellation of Cancer.
This star is unusual in that it is just one of a handful that are known to have at least 5 planets. The innermost of these planets--55 Cancri e--was discovered in 2004 and has since had plenty of attention from astronomers. Various groups have observed the the changes in radial velocity that it causes its parent star. This tells them about that it orbits its star every 18 hours and that its mass is about 8 times Earth's or about half Neptune's."
Friday, October 14, 2011
Mela, Pomponius
Munich Digitization Center
Digitised works/ Author: Mela, Pomponius
http://www.digital-collections.de/index.html?c=autoren_index&l=en&ab=Mela%2C+Pomponius
Thursday, October 13, 2011
Indos
De chorographia, Liber III
"Mais à l'autorité des anciens philosophes et d'Homère, qui ont prétendu que la terre était de tous côtés environnée par la mer, on peut ajouter celle de Cornélius Nepos, qui, étant plus moderne, est par conséquent plus sûr. Or, cet auteur rapporte, à l'appui de cette opinion , le témoignage de Q. Metellus Celer, auquel il fait dire qu'étant proconsul dans la Gaule, le roi des Botos lui fit présent de quelques Indiens , et que, s'étant informé d'où ils étaient venus, il apprit que, les tempêtes les ayant emportés loin de la mer des Indes, ils avaient été jetés, après un long trajet, sur les rivages de la Germanie. Le reste de la côte asiatique est donc baigné au nord par une mer sans bornes; mais cette partie est couverte de glaces éternelles, et par conséquent déserte."
Louis Baudet translation
To the ancient philosophers and Homer, who claimed that the land was surrounded on all sides by the sea, we may add Cornelius Nepos, who, being more modern, is therefore more reliable. However, this author reports in supporting this fact, the witness of Q. Metellus Celer: when he was proconsul in Gaul, the king of Botos made him a present of a few Indians, and that, being informed of where they came from, he learned that the storms have swept away them of the Indian Ocean. They were thrown, after a long journey, on the shores of Germania. The rest of the northern Asian shores are surrounded by the sea, but this part is covered with eternal ice, and therefore deserted.
King Arthur's round table
How to measure the stair angle
use a protractor (available at most hardware stores) to determine this angle.
I am proposing that Kha the architect at Deir El-Medina, Egypt, supervisor of the projects of three kings of the 18th Dynasty used his protractor to check the inclination of stairs for instance. You can see it at the Egyptian Museum of Torino. Read more at http://stretchingtheboundaries.blogspot.com/2011/08/khas-protractor.html
Saturday, October 8, 2011
Kha
Back to Kha's protractor
In the post "Kha's protractor", I have discussed an object found in the tomb of an ancient egyptian architect, Kha. It can be used to measure angles.Plums, levels, protractors , compasses and so on are instruments for surveying. See http://en.wikipedia.org/wiki/Surveying and the table http://en.wikipedia.org/wiki/File:Table_of_Surveying,_Cyclopaedia,_Volume_2.jpg
In this table there is the image of a compass rose. We can start from it and go back to the Kha's rose.
Tuesday, October 4, 2011
Romans in America?
In fact, there's a growing amount of evidence suggesting that a lot of the familiar history of human exploration and "discovery" by our ancestors as we were taught it may be quite wrong. There is hard evidence of ancient civilizations making their mark in places where, according to traditionally accepted history, they just shouldn't be. Here's an overview of some of the most remarkable and fascinating cases."
read more
At http://paranormal.about.com/od/ancientanomalies/a/History-Mystery-Ancients-In-America.htm
Friday, September 30, 2011
Fairy chimneys in Peru
The erosion of water and wind on the rocks is able to create beautiful landscapes. Some places are well-known and have been declared natural heritage sites by UNESCO; some others are in desert and hostile regions, hard to visit. In most cases, just the local population knows these landscapes. In this post we will see that the simple action of some users of World Wide Web services, such as the Google Maps, in uploading their pictures, allows the discovery, study and perhaps future preservation of some of them. We will see in particular the case of some fairy chimneys in
References