"Richard Hoover, an astrobiologist at the US space agency's Marshall space flight centre in Alabama, said filaments and other structures in rare meteorites appear to be microscopic fossils of extraterrestrial beings that resemble algae known as cyanobacteria. Some of the features look similar to a giant bacterium called Titanospirillum velox, which has been collected from the Ebro delta waterway in Spain, according to a report on the findings.... Hoover, an expert on life in extreme environments, has reported similar structures in meteorites several times before. So far, none has been confirmed as the ancient remains of alien life.
But writing in the Journal of Cosmology, Hoover claims that the lack of nitrogen in the samples, which is essential for life on Earth, indicates they are the remains of extraterrestrial life forms that grew on the parent bodies of the meteorites when liquid water was present, long before the meteorites entered the Earth's atmosphere."
Sunday, March 6, 2011
Friday, March 4, 2011
Image processing?
"An interdisciplinary group of researchers is calling for the help of other scientists to help them to understand how some of the key features of human vision have evolved. The team, led by Gasper Tkačik, a physicist at the University of Pennsylvania, has compiled a database of roughly 5000 images of the Okavango Delta region in Botswana. This tropical savannah habitat is believed to be similar to the conditions that existed in Africa around 20–30 million years ago, at the time of the origins of Old World monkeys, when the basic adaptations in our visual system are thought to have evolved."
Snapping the birthplace of the human eye - physicsworld.com
by James Dacey Snapping the birthplace of the human eye - physicsworld.com
Snapping the birthplace of the human eye - physicsworld.com
by James Dacey Snapping the birthplace of the human eye - physicsworld.com
Thursday, March 3, 2011
Die bunten Buddhas
Afghanistan - Die bunten Buddhas von Bamiyan – für immer verloren?
"Seit dem 6. Jahrhundert blickten zwei riesige Buddha- Statuen auf das Tal von Bamiyan in Afghanistan – ehe die Taliban die Standbilder 2001 in wenigen Tagen zerstörten. Erst nach dem Sturz des Regimes hatten Forscher die Möglichkeit, die Statuen mit modernen Methoden zu untersuchen. Anhand der Bruchstücke will man nun Bautechnik und Farbgebung rekonstruieren und die Möglichkeiten eines Wiederaufbaus beurteilen."
"Seit dem 6. Jahrhundert blickten zwei riesige Buddha- Statuen auf das Tal von Bamiyan in Afghanistan – ehe die Taliban die Standbilder 2001 in wenigen Tagen zerstörten. Erst nach dem Sturz des Regimes hatten Forscher die Möglichkeit, die Statuen mit modernen Methoden zu untersuchen. Anhand der Bruchstücke will man nun Bautechnik und Farbgebung rekonstruieren und die Möglichkeiten eines Wiederaufbaus beurteilen."
Wednesday, March 2, 2011
Horse and dog - Tang Dinasty - China
An animal sits on a pad behind the saddle.
Hunters can have a dog or a cheetah with them.
China
Museo Arte Orientale, Torino
Tiny antennas for radio telescopes
"Tiny antennas form vast radio telescope array.
A grassroots telescope array is taking aim at a wide range of astronomy questions, with projects in geophysics and agriculture piggybacking on its infrastructure.
Dipole antennas dotting the Netherlands and several nearby countries together form a radio telescope that is sensitive in the relatively unexplored wavelength range of 1–10 m (roughly 10–250 MHz) and has an enormous field of view. About three-fourths of the telescope’s 44 stations are functioning, and the rest are set to be completed by the end of the year."
Dipole antennas dotting the Netherlands and several nearby countries together form a radio telescope that is sensitive in the relatively unexplored wavelength range of 1–10 m (roughly 10–250 MHz) and has an enormous field of view. About three-fourths of the telescope’s 44 stations are functioning, and the rest are set to be completed by the end of the year."
by Toni Feder, Physics Today March 2011
Tiny antennas form vast radio telescope array - Physics Today March 2011
It is the International LOFAR Telescope
http://www.lofar.org/about-lofar/image-gallery/latest-lofar-images
It is a radio interferometric array, consisting of many low-cost antennas. There are two distinct antenna types: the Low Band Antenna (LBA) between 10 and 90 MHz and the High Band Antenna (HBA) between 110 and 250 MHz. These "sensors" are organised many stations, distributed over an area about one hundred kilometres in diameter, located in the North-East of the Netherlands. This infrastructure will give rise to new resources for non-radio astronomers. In the geosciences field, it should be possible, for example, to extend the understanding of natural and induced seismicity, subsidence, and water management. The agricultural application of LOFAR is in the measurement of the micro-climate.
Tiny antennas form vast radio telescope array - Physics Today March 2011
It is the International LOFAR Telescope
http://www.lofar.org/about-lofar/image-gallery/latest-lofar-images
It is a radio interferometric array, consisting of many low-cost antennas. There are two distinct antenna types: the Low Band Antenna (LBA) between 10 and 90 MHz and the High Band Antenna (HBA) between 110 and 250 MHz. These "sensors" are organised many stations, distributed over an area about one hundred kilometres in diameter, located in the North-East of the Netherlands. This infrastructure will give rise to new resources for non-radio astronomers. In the geosciences field, it should be possible, for example, to extend the understanding of natural and induced seismicity, subsidence, and water management. The agricultural application of LOFAR is in the measurement of the micro-climate.
Acoustics of free-reed instruments
Documents dating back to before 1000 BC describe a wind instrument whose reed vibrates back and forth across the frame that houses it. Nowadays, free-reed instruments inspire both scholarly study and musical innovation. James Cottingham , Acoustic of free-reed instruments, Physics Today, March 2011, Vol.63, pp. 44-48.
A free reed? What is it? More http://www.patmissin.com/history/whatis.html
A free reed? What is it? More http://www.patmissin.com/history/whatis.html
Tuesday, March 1, 2011
Nazca
"The Nasca culture was the archaeological culture that flourished from 100 to 800 AD beside the dry southern coast of Peru in the river valleys of the Rio Grande de Nazca drainage and the Ica Valley (Silverman and Proulx, 2002). Having been heavily influenced by the preceding Paracas culture, which was known for extremely complex textiles, the Nasca produced an array of beautiful crafts and technologies such as ceramics, textiles, and geoglyphs (most commonly known as the Nazca lines)."
More Wiki
Cahuachi - pyramids
"Hablar de Cahuachi es hablar de una ciudad perdida en la noche de los tiempos. Cahuachi fue la capital teocrática de la Cultura Nasca gobernada por sacerdotes". More http://www.peruecologico.com.pe/esp_cahuachinasca_1.htm
Cahuachi was the major ceremonial center of the Nazca culture from 1 CE to about 500 CE. The "ciudad perdida" contains over 40 mounds topped with adobe structures. The permanent population was quite small. The town was apparently a pilgrimage center that grew its population during the ceremonial events. These events probably involved the Nazca lines.
"Cahuachi's most famous monument is the Great Pyramid, which hogs the skyline and casts an eye over the Nazca Lines, the geoglyphs which have made the culture so famous. As with most buildings in the city, the pyramid looks like a giant maze thanks to the winding ceremonial staircases which lead to its summit.... Many ceramics and other ceremonial items, such as fabrics and paintings, have been found in Cahuachi. ... Like many pre-Columbian American cities, Cahuachi was mysteriously abandoned, around 500 AD."
Cahuachi was the major ceremonial center of the Nazca culture from 1 CE to about 500 CE. The "ciudad perdida" contains over 40 mounds topped with adobe structures. The permanent population was quite small. The town was apparently a pilgrimage center that grew its population during the ceremonial events. These events probably involved the Nazca lines.
"Cahuachi's most famous monument is the Great Pyramid, which hogs the skyline and casts an eye over the Nazca Lines, the geoglyphs which have made the culture so famous. As with most buildings in the city, the pyramid looks like a giant maze thanks to the winding ceremonial staircases which lead to its summit.... Many ceramics and other ceremonial items, such as fabrics and paintings, have been found in Cahuachi. ... Like many pre-Columbian American cities, Cahuachi was mysteriously abandoned, around 500 AD."
Thanks to Wikipedia and Ed88!
Flying on Andes
"Birds were precious resources in the economy of Andean societies. Merchants traded brilliantly colored parrot and macaw feathers in long-distance networks connecting the Amazonian rainforest, the Cordillera, and the remote Pacific coast, where they adorned the sumptuous garments of rulers and kings. Coastal agriculturalists used guano to enrich their fields. Sailors collected the valuable fertilizer offshore on sacred islands, where they left prestigious offerings. On the coast, domesticated muscovy ducks may have been part of the subsistence."
Birds of the Andes, by Hélène Bernier, Source: Birds of the Andes | Thematic Essay | Heilbrunn Timeline of Art History | The Metropolitan Museum of Art
Birds of the Andes, by Hélène Bernier, Source: Birds of the Andes | Thematic Essay | Heilbrunn Timeline of Art History | The Metropolitan Museum of Art
Amazon Earthworks
Ancient Amazon Earthworks Seen by Satellite
"Amazonia is not the “wilderness” many assume it to be. For thousands of years human beings have been residing in and cultivating lowland and upland areas across the Amazon basin and beyond.
A recent article in National Geographic News provides a glimpse of earthworks built long before Columbus. Rediscoveries of the ancient croplands and city sites force us to re-evaluate notions of wilderness and to consider the long-standing, organized, cultural interactions and influences of humanity upon western landscapes."
"Amazonia is not the “wilderness” many assume it to be. For thousands of years human beings have been residing in and cultivating lowland and upland areas across the Amazon basin and beyond.
A recent article in National Geographic News provides a glimpse of earthworks built long before Columbus. Rediscoveries of the ancient croplands and city sites force us to re-evaluate notions of wilderness and to consider the long-standing, organized, cultural interactions and influences of humanity upon western landscapes."
http://news.nationalgeographic.com/news/2010/01/100104-amazon-lost-civilization-circles.html
http://archaeologynewsnetwork.blogspot.com/2010/11/amazonian-geoglyphs.html
http://archaeologynewsnetwork.blogspot.com/2010/11/amazonian-geoglyphs.html
Hidden simplicity
Hidden simplicity
"Casey and Anderson’s idea is based on the ansatz that the strange metal phase of the cuprates is described by an ordinary, well-understood Fermi-liquid theory that exists, but which is hidden in an unphysical Hilbert space (an analog of a Platonic world). In this picture, projecting the familiar Fermi liquid back into the physical world (i.e., making a measurement) converts the Fermi liquid into the experimentally observed strangeness. If Casey and Anderson’s theory withstands further experimental scrutiny, it will surely be a leap forward in our understanding of the cuprates. "– Alex Klironomos, Hidden simplicity
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.097002
Phys. Rev. Lett. 106, 097002 (2011)
Hidden Fermi Liquid: Self-Consistent Theory for the Normal State of High-TcSuperconductors
Philip A. Casey and Philip W. Anderson
Hidden Fermi liquid theory explicitly accounts for the effects of Gutzwiller projection in the t-J Hamiltonian, widely believed to contain the essential physics of the high-Tcsuperconductors. We derive expressions for the entire “strange metal,” normal state relating angle-resolved photoemission, resistivity, Hall angle, and by generalizing the formalism to include the Fermi surface topology—angle-dependent magnetoresistance. We show this theory to be the first self-consistent description for the normal state of the cuprates based on transparent, fundamental assumptions. Our well-defined formalism also serves as a guide for further experimental confirmation.
Phys. Rev. Lett. 106, 097002 (2011)
Hidden Fermi Liquid: Self-Consistent Theory for the Normal State of High-TcSuperconductors
Philip A. Casey and Philip W. Anderson
Hidden Fermi liquid theory explicitly accounts for the effects of Gutzwiller projection in the t-J Hamiltonian, widely believed to contain the essential physics of the high-Tcsuperconductors. We derive expressions for the entire “strange metal,” normal state relating angle-resolved photoemission, resistivity, Hall angle, and by generalizing the formalism to include the Fermi surface topology—angle-dependent magnetoresistance. We show this theory to be the first self-consistent description for the normal state of the cuprates based on transparent, fundamental assumptions. Our well-defined formalism also serves as a guide for further experimental confirmation.
One-way sound
One-way sound
" Xue-Feng Li and colleagues at Nanjing University and California Institute of Technology report on a new acoustic diode design that manipulates the sonic crystal itself to achieve nonreciprocal propagation of sound. The device consists of a two-dimensional sonic crystal arranged in a mesh of square steel rods. By rotating the steel rods, Li et al.are able to manipulate the unit cell of the sonic crystal element to turn the diode on (sound waves only propagate one way) and off (sound waves can move back and forth). Li et al. make their device entirely from linear acoustic materials, which allows them to control sound propagation with a simpler and more efficient process". – Daniel Ucko, One-way sound