that is, ideas and information on Science and Technology, Archaeology, Arts and Literatures. Physics at http://physics-sparavigna.blogspot.com/
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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
Speed of neutrinos and cosmic consequences
"In September 2011 the OPERA collaboration released calculations showing velocities of 17-GeV and 28-GeV neutrinos exceeding the speed of light in their experiments. The authors write, "Despite the large significance of the measurement reported here and the stability of the analysis, the potentially great impact of the result motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly." This result had not been detected by previous experiments, and lies in contrast to several others. For instance, photons and neutrinos from SN 1987A were observed to have an agreement in transit time to about 1 part in 450 million, with even this difference being accounted for by light being impeded by the material of the star early in its journey. The OPERA results, in contrast, suggested that neutrinos were traveling faster than light by a factor of 1 in 40,000, i.e. that neutrino speed is 1.0000248(28)c. Had neutrinos from SN 1987A (a supernova, approximately 168,000 light-years from Earth, http://en.wikipedia.org/wiki/SN_1987A) traveled faster than light by this factor, they would have arrived at Earth several years before the photons; this was not observed to be the case. However, neutrinos from the supernova had orders of magnitude less energy than the neutrinos observed in the OPERA experiment, as the authors point out."
Friday, September 23, 2011
Neutrino: fast and furious
http://www.guardian.co.uk/science/2011/sep/23/faster-light-neutrinos
"Scientists at the Opera (Oscillation Project with Emulsion-tRacking Apparatus) experiment in Gran Sasso, Italy, found that beams of neutrinos sent to its detectors from Cern, 730km away in Geneva, arrived earlier than they should have."
Thursday, September 22, 2011
Coherers as “energy catalyzers”
Amelia Carolina Sparavigna
Dipartimento di Fisica,
Politecnico di Torino, Torino, Italy
------------
On Wednesday September 21, 2011, from the news of RAI, the Italian broadcaster, I learned that a new device for energy production was on the way for industrial developments. I had not immediately realized the features of this device, but I memorized the fact that it was based on water, nickel powders and current, that I saw sparkling in the video clip. After searching on the Web, I found that the announced device was the energy catalyzer, E-Cat, under patent request by its inventor, Andrea Rossi. The development of prototypes was due to the work of Rossi and Sergio Focardi, University of Bologna. It seems that they have announced a device able of producing more than 10 kilowatts of heat power, while only consuming a fraction of that. "On January 14, 2011, they gave the Worlds' first public demonstration of a nickel-hydrogen fusion reactor capable of producing a few kilowatts of thermal energy. At its peak, it is capable of generating 15,000 watts with just 400 watts input required. In a following test the same output was achieved but with only 80 watts of continual input" [1]. The item is also reporting that the inventor prefers to invoke a catalyzer process, not to a cold fusion. There are so many Web pages on the E-Cat, that it is impossible to list them, but an exhaustive one is the corresponding Wikipedia item [2]. It is there that we can find the reference to the patent [3], which is about a "method and apparatus for carrying out a highly efficient exothermal reaction between nickel atoms and hydrogen atoms, in a tube, preferably, though not exclusively made of a metal, filled by a nickel powder and heated to a high temperature preferably, though not necessarily, from 150 to 5000°C, by injecting hydrogen into said metal tube said nickel powder being pressurized, preferably, though not necessarily, to a pressure from 2 to 20 bars ".
The confidence on this device does not allow its discussion. And in fact, the aim of my paper is not a discussion on E-Cat, but on what the poor information on it suggested me. Some features of the device attracted my interest: they are the metal powders, the high temperatures and the sparks of electricity. In fact I read recently about all these things together in a old book published in 1904, entitled Element of Physics, by Fernando Sanford, professor at the Stanford University, one of the members of the group of scientists who came there to create the pioneer faculty in 1891. In [4], I discussed the experiments of Sanford on the electric photography and the fact that, several years after in 1939, the fringes around the electrically photographed objects had been rediscovered by Semyon Kirlian. Of course the book written by Sanford is quite old, but, in my opinion, it has to be appreciated due to the fact that it is based on the description of experiments. The book is then quite interesting from the point of view of experimental physics and for its history. A chapter is devoted to electric radiation and electric waves. Let us remember that Fernando Sanford was talking of experiments, which, at his times were revolutionizing physics and technology. Reading the book we learn that a new device was used in laboratories, the Coherer (see Fig.1). Let me report the Laboratory Exercise 119 of the book
"Take a glass tube of about a centimeter bore and six or eight centimeters long, fit the ends with corks through which copper wires can be passed, and fill the tube between the corks with brass or iron filings. Thrust copper wires through the corks and into the iron filings until their ends are one or two centimeters apart. Connect these wires in circuit with one or more voltaic cells and a tolerably sensitive galvanometer. The resistance of the filings to the passage of a current should be so great that the galvanometer is slightly, if at all, deflected. Bring an electric machine near, and pass sparks from one discharging knob into one of the wires which enter the tube. The resistance should fall so that the galvanometer is deflected through nearly 90°. This instrument is called a Coherer. The passage of the electric discharge into the small metallic particles in the tube apparently causes them to cling together so that they make better electric contact than before. After your coherer has become sensitive enough to allow the passage of a suitable current, increase its resistance again by tapping gently on the glass and causing the particles to separate. Then move the electric machine to a distance of a few feet from the coherer and turn the handle and cause sparks to pass between the discharging knobs of the machine. If your coherer has been properly adjusted, the galvanometer will be deflected again, showing that the resistance of the coherer has been again diminished. By a little care in the adjustment, and by using a sensitive galvanometer, the coherer will respond to a spark at a distance of several yards. ... The Coherer described above is similar to the receiver used in "wireless telegraphy." The Coherer is connected between a battery and a telegraph sounder, and is attached to a long wire or other conductor suspended at some height. A similar conductor is suspended at the sending station, and is connected with the spark gap of the electric machine or induction coil. The oscillations in the receiving conductor are accordingly partly due to resonance, and they are sufficient to lower the resistance of the coherer so that a signal can be made through it. An automatic tapper jars the particles apart, so that the signal is momentary unless the instrument is sensitized by another spark. "
The device described by Sanford is a radio signal detector used in the receivers of wireless telegraphy at the beginning of the twentieth century. The coherer was invented, around 1890, by Édouard Branly [5]. As described by Sanford, it consisted of a tube or capsule containing two electrodes spaced a small distance apart, with metal filings in the space between them. To have the Branly effect, it is necessary a thin resistive layer between the grains, to have an initial high resistance. The effect is not observed with noble metal grains, cleaned from any surface contaminant. The coherer works because the metal particles cling together, that is cohere after being subjected to the radio frequency electricity. This provokes a reduction in the coherer's electrical resistance, which is persistent after the radio signal. To receive another signal, the device needs a de-coherer mechanism, able to tap the coherer, mechanically disturbing the particles and resetting them to the high resistance state. As Wikipedia [5] is telling "Coherence of particles by radio waves is an obscure phenomenon that is not well understood even today", but several recent experiments with metal particles seem to confirm that particles cohere by a micro-weld phenomenon, caused by radio frequency electricity fluxing across the small contact area between particles. This phenomenon is probably involving a tunnelling of charge carriers across an imperfect junction between conductors, as deeply discussed in Ref.6. In fact, in this reference the author is proposing to relate the Branly effect to the induced tunnelling effect first described by François Bardou and Dominique Boosé, asserting then that the effect is mainly governed by an electrical tunnel effect [7].
In the work published in 2001 [7], Bardou and Boosé theoretically proposed that the tunnelling probability of a particle through a potential barrier could be enhanced by striking the particle when the centroid of its wave packet is reflecting on the barrier. This is applied to Branly effect as discussed in [6] in the following way. “In a granular metallic medium microscopic grains are electrically isolated one from the other by a metal oxide nanometric layer ... When a voltage is applied to the medium, electrons are accelerated and they do reflect on the potential barriers. At the time of the reflection, these electrons can be kicked forward or backward by the short electromagnetic pulses present in the external electromagnetic field. … The enhanced transmission induced by the momentum transfer produces an increased electrical current, that for some events become large enough to permit a local heating in the metal grains thanks to the Joule effect. Eventually a welding of the grains can occur and when a percolation path has formed the electrical resistance of the medium drops down going from an exponential dependence on the applied voltage to a linear one”. Reference 6 is also reporting that Auerbach demonstrated in 1898 that a coherer could be made conducting by an acoustic excitation in the audible range of the spectrum. According to [6], this means that acoustical wave, by giving vibrations to tunnel barriers between the metallic grains, could be responsible of an induced tunnelling.
Let us also consider the recent experiments with particle coherers by Falcon et al. [8]. They reported on observations of the electrical transport within a chain of metallic beads, which were slightly oxidised. As the applied current is increased, a transition from an insulating to a conductive state is observed. The authors are proposing that the transition comes from an electro-thermal coupling, at the micro-contacts between each bead. Due to these contacts, the current flows through them, generating a high local heating. This heating increases the local contact areas, enhancing the conduction. This current-induced temperature rise, up to 1050°C, results in the micro-soldering of the contact points, even for low voltages.
If we define an “energy catalyzer” as a device able to produce change in, or transform energy, the coherer acts in such a manner, where the catalyst is an electromagnetic pulse. Let us hope that as soon as possible, an open report on E-Cat is published, in order to understand the role of hydrogen in it. In this device, is any tunnelling present? Is it there a tunnelling able to give a fusion of nickel and hydrogen to have copper in a proton capture as told in [9]? Is there any kicking mechanism? What we find in [9] is that the paper is just reporting the results “obtained with a process and apparatus not described here (in [9]) in detail and protected by patent in 90 countries, consisting of a system whose heat output is up to hundred times the electric energy input. As a consequence, the principle of the conservation of energy ensures that processes involving other energy forms are occurring in our apparatus”. And in the conservation of energy we trust.
References
1. http://peswiki.com/index.php/Directory:Andrea_A._Rossi_Cold_Fusion_Generator
2. http://en.wikipedia.org/wiki/Energy_Catalyzer
3. http://www.wipo.int/pctdb/en/wo.jsp?IA=IT2008000532&DISPLAY=DESC
4. A.C. Sparavigna, Fernando Sanford and the "Kirlian effect", arXiv:1105.1266v1 [physics.pop-ph], http://arxiv.org/ftp/arxiv/papers/1105/1105.1266.pdf
5. http://en.wikipedia.org/wiki/Coherer
6. C. Hirlimann, Understanding the Branly effect, arXiv:cond-mat/0703495v1 [cond-mat.mtrl-sci], http://arxiv.org/ftp/cond-mat/papers/0703/0703495.pdf
7. D. Boosé and F. Bardou, A quantum evaporation effect, Europhys. Lett., 53, 1-7 (2001).
8. E. Falcon, B. Castaing, and M. Creyssels, Nonlinear electrical conductivity in a 1D granular medium, The European Physical Journal B, 38, 475-483 (2004)
9. S. Focardi and A. Rossi, A new energy source from nuclear fusion, http://www.lenr-canr.org/acrobat/FocardiSanewenergy.pdf
Wednesday, September 7, 2011
Magnetic scan without magnets
"Nuclear magnetic resonance is a powerful technique for analyzing molecular structure in biology, medicine, and materials science. Conventionally, it calls for huge magnets to align nuclear spins and to detect them with high sensitivity, but recent work has demonstrated that similar analysis can be done without a magnetic field. The problem with this zero-field technique is that it can’t unambiguously identify molecules. Now, in a paper in Physical Review Letters, Micah Ledbetter of the University of California, Berkeley, and his collaborators address this limitation, showing that a very small magnetic field can provide extra signatures for chemical discrimination."
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.107.107601
Tuesday, August 30, 2011
Concrete in the Great Pyramids
http://www.nytimes.com/2008/04/23/world/africa/23iht-pyramid.1.12259608.html
"It is a theory that gives indigestion to mainstream archaeologists. Namely, that some of the immense blocks of the Great Pyramids of Egypt might have been cast from synthetic material - the world's first concrete - not just carved whole from quarries and lugged into place by armies of toilers. Such an innovation would have saved millions of man-hours of grunting and heaving in construction of the enigmatic edifices on the Giza Plateau."
Wednesday, August 3, 2011
Objeto del antiguo Egipto sería el primer transportador en el mundo
"Un objeto hallado en una tumba egipcia hace más de 100 años sería el primer transportador, función que finalmente se plante tras un largo misterio entre los arqueólogos sobre su utilidad según informa la revista New Scientist."
Connuestroperu Objeto del antiguo Egipto sería el primer transportador en el mundo
Tuesday, August 2, 2011
Toshka Lakes from space
Amelia Carolina Sparavigna, Dipartimento di Fisica, Politecnico di Torino
http://arxiv.org/abs/1107.4430
Toshka Lakes are lakes recently formed in the Sahara Desert of Egypt, by the water of the Nile, conveyed from the Nasser Lake through a canal in the Toshka Depression. From space, astronauts noticed the growing of a first lake, the easternmost one, in 1998. Then additional lakes grew in succession due west, the westernmost one between 2000 and 2001. In fact, sources of precious information on Toshka Lakes are the pictures takes by the crews of space missions and the satellite imagery. They show that, from 2006, the lakes started shrinking. A set of recent images displays that the surface of the easternmost lake is strongly reduced.
Toshka Lakes is the name given to the lakes, quite recently formed, in the Sahara Desert of Egypt. These new lakes are endorheic, that is, the water can never flow out this region toward the sea. They are near the Nasser Lake (see the map in Fig.1), the huge lake created by the Aswan High Dam, built in 1964-1968. As Wikipedia is reporting [1], in 1978, Egypt began to build the Sadat Canal, originating from the Lake Nasser and passing through the Wadi Toshka, to allow the water, when it is overflowing a specific level, to be drained off to flood a depression located at the south end of a desert limestone plateau. This is the Toshka Depression. In fact, the Egyptian government decided to undertake a development project of the surrounding region, known as the "New Valley Project". The project intends to extend this waterway till the Kharga oasis.
It was in late 1990s [1] that the water started flowing in the canal. This waterway, feeding the depression with the water from Nile, was prepared in order to reduce the water losses. This water, in order to flow the Sadat Canal needs a pumping station, which is situated north of Abu Simbel. From space, astronauts noticed the growing of a first lake, the easternmost one, in November 1998 [1]. They saw the other lakes grown in succession westward, the westernmost lake between September 2000 and March 2001. A public source of information on Toshka Lakes is in fact in the pictures taken by the crews of space missions. Starting from 2006, the images show that the lakes started shrinking, because of a reduction of water supply [3]. One of the lakes dried out. As reported in [3], the flooding of the Toshka Depression had created the four wide lakes, with their maximum surface area in 2002, of ca 1,500 km^2 , having about 5 × 10^9 m^3 of water. Some of the water evaporated and some recharges the underlying aquifer [3]. At the beginning of the
flooding, the fauna and flora of Nile invaded the Toshka valley [3], with a resultant very rich population of fishes. But, unfortunately, the water supply reduced. The western-most lake shows a rapidly increasing salinity. As the researches are observing, the zooplankton reacts to the increase of salinity by a striking impoverishment [3]. The life in the lake started to decline. A publication [4] estimated the loss of water from the lakes using remote sensing and GIS, collecting a set of images and processing them to show the aerial extend shrinkage of these lakes from 2002 up to 2007. By means of a spatial analysis of bathymetry in a digital elevation model, the authors found that the loss rate is around 2.5 m/year. They noted that the lakes stored around 25.26 billion cubic meters of water in 2002, but in 2006 the stored water was reduced to 12.57 billion cubic. The authors conclude that the location of these lakes in such hyper-arid zone is
responsible for a high loss rate, mainly caused by the evaporation, because they found the percolation of water through the ground quite limited. They say that “It is strongly recommended that measures must be taken to maximize the benefits of these huge, exceptional water resources before totally lost via evaporation. Additionally, geo-environmental problems are likely to arise from the concentration of salts when the lakes dry up”.
Let us see what happened by means of the NASA satellite imagery. The "NASA Earth Observatory" allow us to see the evolution of the western Toshka Lakes (see Fig.2). In the upper image, we have a figure of the lakes as soon as they formed, 2001. But in 2005, the water level was strongly reduced. In Fig.3, the "NASA Earth Observatory" dated 2005 is compared with an image that we can obtain (on date July 21, 2011) from Google Maps. It is not possible for the author to tell when the Google image had been recorded. But, surely it is more recent, because we see a further reduction of the surfaces of the lakes.
Let us note that reference [4] is dated 2007. But what is the current situation of the lakes?
Let us try to answer using NASA images again, and in particular, those of the easternmost Toshka Lake. In 2005, it was as shown in upper panel of Fig.4, as provided by the "Gateway to Astronaut Photography of Earth". The original image has been enhanced and rotated to compare it with that provided the Google Maps, displayed in the lower panel of Fig.4. As told for Fig.3, it is not possible for me to date the Google image; surely after 2005, because comparing the images, we note that the surface of the lake had shrunk.
Fig.4 The easternmost Toshka Lake in 2005, as provided by the "Gateway to Astronaut Photography of Earth", is shown in the upper panel. The original image has been enhanced and rotated to compare it with that provided (downloaded July 21, 2011) by the Google Maps, displayed in the lower panel. Note that, it is not possible for me to date the Google image. I can only tell thta it is surely after 2005, because comparing the images, we note that the surface of the lake had shrunk.
But the "Gateway to Astronaut Photography of Earth" has a set of images of March 31, 2011, quite recent then, that allowed me to create a composite map of the current aspect of the lake. The map is proposed in Fig.5. This map had been rotated and enhanced as discussed in Ref. 5 (the image processing proposed in [5] has interesting applications in archaeology, see [6]). The processed images have so many details that we can use them to see the evolution of the lake. This is proposed in Fig.6, where we see a part of the lake, as it evolved from 2005 to March 31, 2011. In this figure we pass from the image dated 2005, to that of 2011, through that from Google Maps, of unknown date. This part of the easternmost lake was large in 2005, shrinking between 2005 and 2011, and reduced to one half the original in 2011, as it can be seen in Figure 7, where the superposition of the two NASA images, of 2005 and 2011, is proposed. We see the surface of the lake strongly decreased.
Let me continue with a little bit of history. Egypt had already lived a similar situation, but on a longer period and more than two thousand years ago. In Egypt there are several lakes; one is the Lake Moeris, an ancient saltwater lake in the northwest of the Faiyum Oasis. During the prehistory, the lake had freshwaters due to the high flood of Nile. From the XII Dynasty, in 2300 BC, the natural waterway from the river to the lake was widened and deepened to make a canal which is now known as the Bahr Yussef, "the waterway of Joseph" [7]. This canal served for the purpose to control the flooding of the river and help in irrigating the surrounding area. Moreover, the kings of the twelfth dynasty used the water of the natural lake of Faiyum in the dry periods. In fact these kings transformed the lake into a huge water reservoir, giving the impression that the lake was an artificial excavation, as reported by Pliny the Elder. He is writing, when discussing
the pyramids in his book [8], that two of them are “in the place where Lake Mœris was excavated, an immense artificial piece of water, cited by the Egyptians among their wondrous and memorable works“ [8]. As the surrounding area changed, since the local branch of the Nile shrank, from about 230 BC, the Bahr Yussef became neglected and Lake Moeris began to dry up, creating a depression in the modern province of Faiyum [7].
As the history is showing, it is undoubtedly necessary for the Toshka Lakes what the researches in Ref.4 are recommending, that is, to undertake measures to preserve these water resources and avoid the problem of the salinity of soil when the lakes dry up. Perhaps, it is too late.
References
1. Toshka Lakes, Wikipedia, http://en.wikipedia.org/wiki/Toshka_Lakes
2. In fact, it was with the Mercury missions in the early 1960s, that astronauts began to take pictures of the Earth. The NASA, through its "Gateway to Astronaut Photography of Earth", provides a database with locations, supporting data, and digital images. The images are processed from those coming down from the International Space Station, http://eol.jsc.nasa.gov/. The "NASA Earth Observatory", created in 1999, has the same task. This is considered the principal source of satellite imagery and other scientific information on climate and environment, among the services provided by NASA, for the general public, http://en.wikipedia.org/wiki/NASA_Earth_Observatory, http://earthobservatory.nasa.gov/IOTD/view.php?id=1008
3. Gamal M. El-Shabrawy and Henri J. Dumont, The Toshka Lakes, in, The Nile, Monographiae Biologicae, 2009, Volume 89, III, 157-162.
4. M. El Bastawesy, S. Arafat and F. Khalaf, Estimation of water loss from Toshka Lakes using remote sensing and GIS, 10th AGILE International Conference on Geographic Information Science 2007, Aalborg University, Denmark, pp.1-9.
5. Anelia Carolina Sparavigna, Enhancing the Google imagery using a wavelet filter, 8 Sep 2010, Geophysics (physics.geo-ph); Earth and Planetary Astrophysics (astro-ph.EP), arxiv:1009.1590
6. Amelia Carolina Sparavigna, The satellite archaeological survey of Egypt, 31 May 2011, Geophysics (physics.geo-ph), arXiv:1105.6315
7. http://en.wikipedia.org/wiki/Lake_Moeris
8. Pliny, The Natural History, Translated by John Bostock and H.T. Riley, Henry G. Bohm,
London, 1857
Monday, August 1, 2011
Kha's protractor
Tuesday, July 26, 2011
Longobard Necropolis near the Asti-Cuneo motorway
http://torino.repubblica.it/cronaca/2011/07/25/news/una_necropoli_longobarda_negli_scavi_della_asti-cuneo-19567203/
Necropoli longobarda sulla Asti-Cuneo
http://torino.repubblica.it/cronaca/2011/07/25/news/una_necropoli_longobarda_negli_scavi_della_asti-cuneo-19567203/
The decreasing level of Toshka Lakes seen from space
by Amelia Carolina Sparavigna, Dipartimento di Fisica,
Politecnico di Torino, Torino, Italy
Abstract
Toshka Lakes are lakes recently formed in the Sahara Desert of Egypt, by the water of the Nile, conveyed from the Nasser Lake through a canal in the Toshka Depression. From space, astronauts noticed the growing of a first lake, the easternmost one, in 1998. Then additional lakes grew in succession due west, the westernmost one between 2000 and 2001. In fact, sources of precious information on Toshka Lakes are the pictures takes by the crews of space missions and the satellite imagery. They show that, from 2006, the lakes started shrinking. A set of recent images displays that the surface of the easternmost lake is strongly reduced.
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http://arxiv.org/abs/1107.4430