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

Monday, February 28, 2011

Era de Pando, Peru

"Ancient Village in Liberec Department, Peru. This is a late Archaic site, thought to be created by the same Supe Culture responsible for the larger nearby site, Caral. The site includes and adobe pyramid and about two dozen buildings. A comparison aerial view on Google maps of both Caral and Era de Pando shows the similarities in architectural layout."
More http://www.megalithic.co.uk/article.php?sid=25983

Caral, in Peru, the oldest town in the New World

"In 2001, the oldest town in South America was officially announced. Dating to 2600 BC, it pushed back the date for the “first town” with one millennium. What is even more intriguing, is that the town of Caral has pyramids, contemporary with the Egyptian Pyramid Era....The ancient pyramids of Caral predate the Inca civilization by 4000 years, but were flourishing a century before the pyramids of Gizeh. No surprise therefore that they have been identified as the most important archaeological discovery since the discovery of Machu Picchu in 1911by Philip Coppens, read more http://www.philipcoppens.com/caral.html

Parihuana - Geoglyphs Titicaca

A geoglyph of Titicaca - As seen by Google Maps

Friday, February 25, 2011

Domenico Pacini and the discovery of cosmic rays

Rivista del Nuovo Cimento 
Volume  033  Issue  12  pp  713-756 
Published online:  Fri, 28 Jan 2011

Abstract "During a series of experiments performed between 1907 and 1911, the Italian physicist Domenico Pacini (Marino 1878-Roma 1934), at that time researcher at the Central Bureau of Meteorology and Geodynamics in Roma, studied the origin of the radiation today called “cosmic rays”, the nature of which was unknown at that time. In his conclusive measurements in June 1911 at the Naval Academy in Livorno, and confirmed in Bracciano a couple of months later, Pacini, proposing a novel experimental technique, observed the radiation strength to decrease when going from the surface to a few meters underwater (both in the sea and in the lake), thus demonstrating that such radiation could not come from the Earth’s crust. Pacini’s conclusive experiment was performed, and the results published (in Italian), one year before the famous balloon experiment by Victor Hess, who found the ionization rate to increase with height. While Hess is today celebrated as the discoverer of cosmic rays, Pacini’s work was largely overlooked. Hess was awarded the Nobel Prize in Physics in 1936, two years after the death of Pacini, who had become a full professor of Experimental Physics at the University of Bari and the Director of the local Institute of Physics. The discovery of cosmic rays —a milestone in science— involved several scientists in Europe and in the United States of America and took place during a period characterized by nationalism and lack of communication. Historical, political and personal facts, embedded in the pre- and post-World War I historical context, might have contributed to the substantial disappearance of Pacini from the history of science. This article aims to give an unbiased historical account of the discovery of cosmic rays; in the centenary of Pacini’s pioneering experiments, his work, which employed a technique that was complementary to, and independent of that of Hess, will be duly taken into consideration. A translation into English of  three fundamental early articles by Pacini is provided in the Appendix. "

3D screen with voxels

"Researchers at Southampton University are using the holographic-style display to design a flawless-quality communication system that comes closer to the impression that users are in the same room.
... This ‘HoloVizio’ screen is made up of tiny elements called voxels (rather than pixels) that can represent depth information. Each voxel emits multiple beams of light that vary in colour and intensity depending on which direction they travel."

Bent-Core Liquid Crystals

Most Cited Articles 2009 Japanese Journal Applied Physics
The 10 articles published in JJAP from 2006 to 2008 that were most frequently cited in 2009, in order of publication date. PDF files of the full text of these articles are available free of charge for one year from January 2011.

Bent-Core Liquid Crystals: Their Mysterious and Attractive World,  by Hideo Takezoe, and Yoichi Takanishi, Jpn. J. Appl. Phys. 45 (2006) 597 [Abstract] [Full Text PDF Free ]
Bent-Core Liquid Crystals: Their Mysterious and Attractive World
Structures and properties of liquid crystalline phases formed by bent-core molecules are reviewed. At least eight phases designated as B1–B8 have been found, being unambiguously distinguished from phases formed by usual calamitic molecules due to a number of remarkable peculiarities. In addition to B1–B8 phases, smectic A-like phases and biaxial nematic phases formed by bent-core molecules are also reviewed. The most attractive aspects of this new class of liquid crystals are in polarity and chirality, despite being formed from achiral molecules. The bent-core mesogens are the first ferroelectric and antiferroelectric liquid crystals realized without introducing chirality. Spontaneous chiral deracemization at microscopic and macroscopic levels occurs and is controllable. Moreover, achiral bent-core molecules enhance system chirality. The interplay between polarity and chirality provides chiral nonlinear optic effects. Further interesting phenomena related to polarity and chirality are also reviewed. [DOI: 10.1143/JJAP.45.597]
KEYWORDS: bent-core liquid crystals, polarity, chirality, ferroelectricity, antiferroelectricity, phase structure, layer structure, X-ray diffraction, nonlinear optics, SHG

Thursday, February 24, 2011

La Medusa di Wayland's Smithy

Un crop circle del 2009, che si vede con Google Maps. "Formazione anomala, e spettacolare. È stata riportata da tutti i media internazionali in quanto dotata di una rara quanto unica energia espressiva."

Wayland's Smithy is a Neolithic long barrow and chamber tomb site located near the Uffington White Horse and Uffington Castle, at Ashburyin the English county of Oxfordshire (historically in Berkshire).

Shale gas

From Wiki "Shale gas is natural gas produced from shale. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020."
Study says natural gas use likeky to double, NYTimes, http://www.nytimes.com/2010/06/25/business/energy-environment/25natgas.html?_r=1&src=busln
Dal Sole24ore "L'Eia ha ritoccato le stime sulle riserve nazionali di shale gas - il metano che si ricava da antiche e stratificate formazioni rocciose – più che raddoppiandole. Così, quegli Stati Uniti già abbastanza ossessionati dalla dipendenza dal petrolio d'importazione, scoprono con sollievo di essere una potenza nel gas: secondo l'Eia, nel 2035 il 45% del fabbisogno americano verrà dalle rocce sedimentarie."

Wednesday, February 23, 2011

American mastodon

Mastodons  were large tusked mammal species of the extinct genus Mammut which inhabited Asia, Africa, Europe, North America and Central America from the Oligocene through Pleistocene, 33.9 mya to 11,000 years ago. The American mastodon is the most recent and best known species of the group.
The American mastodon, Mammut americanum,  lived from about 3.7 million years ago until about 10,000 BC. It was the last surviving member of the mastodon family. It is known from fossils found ranging from present-day Alaska and New England in the north, to Florida, southern California, and as far south as Honduras and El Salvador.

Cryogenic energy storage

Cryogenic energy storage plant could provide valuable back-up | News | The Engineer
"The UK’s first cryogenic power storage plant, which uses liquid nitrogen to store and release energy, is scheduled to open next month. Its operator, Highview Power Storage, said the system could provide a relatively cheap way of storing power, particularly from intermittent sources such as wind turbines, to better match the supply of electricity to demand.The pilot facility near Slough has been providing electricity to the National Grid since April last year by evaporating liquid nitrogen stored at -200ºC to drive turbine generators. Highview is now installing equipment to re-liquefy and compress the nitrogen using electricity from the grid, creating a closed cryogenic system that can store energy at times of surplus and release it when it is needed, while re-using the cold air exhaust."

Lanzan pájaro espía

Un miniavión espía en forma de colibrí que funciona a control remoto fue presentado por el Pentágono.

Friday, February 18, 2011

Il tritone e il drago marino

Un tritone combatte con un drago marino
Palazzo Madama, Torino

Physicists create 'anti-laser'

Physicists create 'anti-laser' - physicsworld.com
"In a fascinating case of physics being turned on its head, a group of researchers at Yale University in the US has created an "anti-laser" that almost perfectly absorbs incoming beams of coherent light. The invention is based on a theoretical study reported last summer in which Douglas Stone and his Yale colleagues claimed that such a system could be possible in a device that they call a coherent perfect absorber (CPA). Instead of generating coherent light beams with a laser, the devices absorb incoming coherent light and convert it into either heat or electricity."

DNA puts a new spin on electrons

DNA puts a new spin on electrons - physicsworld.com
"A new and highly efficient way of filtering electrons according to their spin has been built using double strands of DNA. The technique, which has been developed by physicists in Israel and Germany, is about three times more efficient than using magnet-based spin filters. The method could be used in spintronic circuits, which exploit both the spin and charge of electrons, and could even lead to a better understanding of the possible role that spin plays in biological processes."

Wednesday, February 9, 2011

The Sun in 3D

"Beginning on February 6, 2011, the two STEREO spacecraft are 180 degrees apart providing Naval Research Laboratory scientists with a 360-degree view of the Sun. NASA's STEREO (Solar Terrestrial Relations Observatory) spacecraft were launched on October 25, 2006, and have been gathering spectacular images of solar activity, especially solar storms, since the mission began."

Sunday, February 6, 2011

Two splendid suns

"Earth could be getting a second sun, at least temporarily. Dr. Brad Carter, Senior Lecturer of Physics at the University of Southern Queensland, outlined the scenario to news.com.au. Betelgeuse, one of the night sky's brightest stars, is losing mass, indicating it is collapsing. It could run out of fuel and go super-nova at any time.
When that happens, for at least a few weeks, we'd see a second sun, Carter says. There may also be no night during that timeframe."

Friday, February 4, 2011

North Atlantic strait at its warmest for 2000 years

"A stretch of water east of Greenland, considered to be the Arctic's main source of heat from the North Atlantic, is warmer now than it has been in at least 2000 years. That is the claim of researchers in Europe and the US who suggest further warming will amplify the effects of climate change in the Arctic region."
North Atlantic strait at its warmest for 2000 years - physicsworld.com

Aurora boreale su Saturno

Un'aurora boreale su Saturno vista da Hubble

Thursday, February 3, 2011

Fotovoltaico organico

Come celle solari organiche si intendono quei dispositivi la cui parte fotoattiva è basata sui composti organici del carbonio, includendo anche quelle celle più prettamente di tipo ibrido. La struttura base di una cella organica è un "sandwich" composto da un substrato e da una o più sottilissime pellicole contenenti i materiali fotoattivi, in mezzo a due elettrodi conduttivi di cui uno trasparente.
"La gamma di celle solari organiche è ampia e si trova in diversi stadi di ricerca e di maturazione tecnologica e comprende, in sintesi, le celle “dye sensitized” (o DSSC), le celle totalmente organiche (anche dette plastiche), e le celle ibride organico/inorganico. Per le celle DSSC (o di Grätzel, dal nome del loro inventore), la parte fotoelettricamente attiva, spessa qualche micrometro ed inserita tra due elettrodi, è costituita da un pigmento organico, da ossido di titanio e da un elettrolita. Le celle DSSC, ispirandosi al processo di fotosintesi clorofilliana, utilizzano una miscela di materiali in cui un pigmento assorbe la radiazione solare e gli altri componenti estraggono la carica per produrre elettricità. Infatti è possibile ottenere l’effetto fotovoltaico anche con pigmenti vegetali. Efficienze massime del 10-11% e tempi di vita di vari anni, valori comunque in costante aumento, sono stati misurati in laboratorio per questo tipo di cella singola, utilizzando pigmenti sintetizzati attraverso i processi della chimica organica. ...
Le celle fotovoltaiche completamente organiche, sia quelle a “small molecules”, realizzate attraverso un’evaporazione sotto vuoto, sia quelle polimeriche, realizzate attraverso deposizione in forma liquida, sono recentemente arrivate al 4-5% di efficienza massima per celle in laboratorio. Queste celle, anche conosciute come “plastiche”, sono molto interessanti in quanto le tecniche di fabbricazione sono le più semplici da attuare."

More Rinnovabili.it: L’evoluzione “organica” delle celle fotovoltaiche

Drilling for geothermal energy

"An exploration team in Newcastle plan to drill through old mining tunnels to search for geothermal energy under the city centre. Researchers from Newcastle University who are leading the project hope it could initially provide up to 5MW of thermal energy, with potentially more heat and electricity from future boreholes. This would provide heat for a new campus that will combine research facilities with affordable housing, while some energy may be siphoned off the power a nearby shopping centre."
Read more Drilling to begin on Newcastle geothermal energy scheme | News | The Engineer

Polarization of light

At the HyperPhysics site you can find a classification of the polarization of light.

The 3D light for spintronics

"Circularly polarized light, which is used in 3D movies, has its electric field vector rotating like a clock hand. It's typically produced by sending light through a filter, but now a team has created a small, solid device that emits partially circularly polarized light, as they describe in the 4 February Physical Review Letters. If this semiconductor technology can be further perfected, it could be used in devices that help biochemists control protein synthesis or help physicists control electrons in spintronics--a futuristic type of electronics." More in "Giving Light a Spin", Physical Review Focus

Nanobeads with liquid hydrogen to fuel cars?

"Plastic nanobeads that can store hydrogen at room temperature as a liquid are being commercialised for fuel applications by technology start-up Cella Energy." This is announced in an article by Andrew Czyzewski, The Engineer. More Nanobeads could store liquid hydrogen to fuel cars | News | The Engineer

Atlantic Wind Connection

Su Google. "... il gigante di Mountain View lancia un progetto mastodontico di energia eolica per le famiglie americane. Si chiama Atlantic Wind Connection (Awc) ed un progetto che si pone l'obiettivo di portare energia pulita nelle case di almeno due milioni di famiglie americane della East Coast. Il progetto vede coinvolta Google e vale sulla carta circa cinque miliardi di dollari, cifra necessaria per erigere a circa 15 miglia dalla costa degli Stati Uniti bagnata dall'Oceano Atlantico una dorsale di turbine eoliche lunga 350 miglia, che partirebbe da New York per raggiungere in direzione Sud la Virginia in quel di Norfolk."
More sole24ore

A star and six planets

"A newfound planetary system has six worlds, five of which rank among the smallest known, and the list of unconfirmed candidates has swelled to four figures.
Thirty million kilometers away, trailing the pale blue dot that is Earth as it orbits the sun, is a spacecraft designed to find some of the countless other pale blue dots that may speckle the galaxy. NASA launched this spacecraft, known as Kepler, in 2009 to take a census of Earth-like planets in the hopes of figuring out how common—or how rare—are the conditions under which life has thrived here."

Una stella e sei pianeti

"Una stella molto simile al Sole ed intorno a lei 6 pianeti che ruotano, un vero e proprio Sistema solare. Ma non è certo il nostro, dato che sta a 2.000 anni luce dalla Terra, una distanza enorme su scala umana, ma molto piccola i termini astronomici. La stella si chiama Kepler 11 e la scoperta del sistema di sei pianeti, tutti piccoli e alcuni con caratteristiche di tipo terrestre, è riportata nella rivista Nature del 3 febbraio."