Wednesday, September 26, 2012

Precious treasures at a height!

It was only a few years ago when I literally stumbled into the Tirthan Valley in Himachal Pradesh and found myself at a gateway leading to one of India’s ‘youngest’ national parks — The Great Himalayan National Park. A pair of White Capped Red Starts flitted along the banks of the Tirthan river which kept me company as I walked the 10 km stretch to the park entrance from where all the treks begin.
The park was officially declared in 1999, and has over the years expanded by incorporating adjoining ‘protected areas’ and wildlife parks into its fold, bringing the total area under administration to 1,171 sq km.
More recently, in 2010, both the Sainj and Tirthan Wildlife Sanctuaries were also added to the GHNP, but will only be formally incorporated once the process known as ‘settlement of rights’ is completed. Covering a large area, the GHNP is contiguous with the Pin Valley National Park (675 sq km) in Trans-Himalaya, the Rupi Bhabha Wildlife Sanctuary (503 sq km) in Sutlej watershed and the Kanawar Wildlife Sanctuary (61 sq km).
Such a large, unbroken and protected expanse of wilderness is like an Eden for flora and fauna to flourish. Geographically speaking, the park seems to encompass almost everything from dense oak and walnut forests, alpine valleys and meadows to patches of high altitude pink rhododendrons which finally give way to a treeless rocky and glacial terrain at 6,100 metres at it’s highest point.
The GHNP is a hotspot for biodiversity and is home to some of the most vulnerable and endangered species. In all, there are 375 recorded faunal species
within the park, a number which is likely to increase, as research and studies indicate. These include the Snow Leopard, the Himalayan Black and Brown Bear, the Royle’s Vole, the Himalayan Tahr, the leopard, the Himalayan Pit Viper, the Musk deer, the Monal and the Western Tragopan, to name just a few.
The Western Tragopan, which is also on the logo of the GHNP, is considered to be the rarest of pheasants in the world. Juju Rana, as it is locally known, literally translates as the king of birds. According to local legend, when the creator was making the world she decided to make something special. So she asked all the birds to give one feather each and from that she created the Juju Rana. It is this biodiversity and its uniqueness that has got the GHNP nominated to the status of a Unesco World Heritage Site.
Unesco will be evaluating the national park this coming month and consider awarding it the status of a World Heritage Site — a status which earlier this year the Western Ghats was awarded, but was declined by the Goa and the Karnataka Governments, presumably owing to the gigantic mining mafia that exists in the region. It is ironic that the very minerals and metals the human race is after are below the most pristine and ancient forests. To open up a forest to be scraped and gouged for mining is to seal not only the fate of the forest, but also everything around it and connected with it.
The GHNP has been nominated specifically under two criteria. The first criterion is that the site should contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance.
The second condition is that it should contain the most important and significant natural habitats for in situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation. The nomination itself is testimony to the fact that GHNP is amongst the top most biologically diverse and vital natural habitats on our planet.
Unfortunately, it is this very fact which is also one of the reasons why the GHNP is threatened. The forests with their diversity in both flora and fauna, have long been used by the communities that have lived in and around them. Local village communities used the meadows and wild lands to graze domestic cattle and sheep, collect forest produce, especially medicinal plants, and to hunt for wild meat in a sustainable manner.
The second half of this story is not new. Commercial gain comes sweeping in and turns everything inside out. Accelerating development, including mining, tourism, hydro-electric dams, timber/forest encroachment and even military use, are taking a toll on this protected habitat. One other activity which began small but has grown disturbingly fast to a vast scale is the illegal collection of medicinal plants.
During my time at the GHNP, I was told about how the demand for these medicinal plants comes from the cities and how then these plants are exported out of the country. The locals are shown photographs of the plant, fungus or root that is in demand, given a rate and sent out in hordes. The entire pipeline is extremely organised and run by a mafia.
The biggest demand these days is for a plant locally called Naag Chhatri. It is the root of the plant that is sought after. Needless to say, to harvest it the entire plant is killed. The plant itself is extremely medicinal in nature and is apparently used as a cure for everything — from fever to high blood pressure. The exact number of people involved is not known, but the quantities extracted from the forest are reportedly huge. So huge that it poses a very real threat to actually cause a local extinction of the species.
A space-time crystal, however, has only existed as a concept in the minds of theoretical scientists with no serious idea as to how to actually build one – until now. An international team of scientists led by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has proposed the experimental design of a space-time crystal based on an electric-field ion trap and the Coulomb repulsion of particles that carry the same electrical charge. "The electric field of the ion trap holds charged particles in place and Coulomb repulsion causes them to spontaneously form a spatial ring crystal," says Xiang Zhang, a faculty scientist with Berkeley Lab's Materials Sciences Division who led this research. "Under the application of a weak static magnetic field, this ring-shaped ion crystal will begin a rotation that will never stop. The persistent rotation of trapped ions produces temporal order, leading to the formation of a space-time crystal at the lowest quantum energy state." Because the space-time crystal is already at its lowest quantum energy state, its temporal order – or timekeeping – will theoretically persist even after the rest of our universe reaches entropy, thermodynamic equilibrium or "heat-death." Zhang, who holds the Ernest S. Kuh Endowed Chair Professor of Mechanical Engineering at the University of California (UC) Berkeley, where he also directs the Nano-scale Science and Engineering Center, is the corresponding author of a paper describing this work in Physical Review Letters (PRL). The paper is titled "Space-time crystals of trapped ions." Co-authoring this paper were Tongcang Li, Zhe-Xuan Gong, Zhang-Qi Yin, Haitao Quan, Xiaobo Yin, Peng Zhang and Luming Duan. The concept of a crystal that has discrete order in time was proposed earlier this year by Frank Wilczek, the Nobel-prize winning physicist at the Massachusetts Institute of Technology. While Wilczek mathematically proved that a time crystal can exist, how to physically realize such a time crystal was unclear. Zhang and his group, who have been working on issues with temporal order in a different system since September 2011, have come up with an experimental design to build a crystal that is discrete both in space and time – a space-time crystal. Papers on both of these proposals appear in the same issue of PRL (September 24, 2012). Ads by Google IIT JEE Syllabus - Video Lectures of Complete IIT JEE Syllabus By IITians. Order Free DVD - KaySonsEducation.co.in Traditional crystals are 3D solid structures made up of atoms or molecules bonded together in an orderly and repeating pattern. Common examples are ice, salt and snowflakes. Crystallization takes place when heat is removed from a molecular system until it reaches its lower energy state. At a certain point of lower energy, continuous spatial symmetry breaks down and the crystal assumes discrete symmetry, meaning that instead of the structure being the same in all directions, it is the same in only a few directions. "Great progress has been made over the last few decades in exploring the exciting physics of low-dimensional crystalline materials such as two-dimensional graphene, one-dimensional nanotubes, and zero-dimensional buckyballs," says Tongcang Li, lead author of the PRL paper and a post-doc in Zhang's research group. "The idea of creating a crystal with dimensions higher than that of conventional 3D crystals is an important conceptual breakthrough in physics and it is very exciting for us to be the first to devise a way to realize a space-time crystal." Just as a 3D crystal is configured at the lowest quantum energy state when continuous spatial symmetry is broken into discrete symmetry, so too is symmetry breaking expected to configure the temporal component of the space-time crystal. Under the scheme devised by Zhang and Li and their colleagues, a spatial ring of trapped ions in persistent rotation will periodically reproduce itself in time, forming a temporal analog of an ordinary spatial crystal. With a periodic structure in both space and time, the result is a space-time crystal. "While a space-time crystal looks like a perpetual motion machine and may seem implausible at first glance," Li says, "keep in mind that a superconductor or even a normal metal ring can support persistent electron currents in its quantum ground state under the right conditions. Of course, electrons in a metal lack spatial order and therefore can't be used to make a space-time crystal." Li is quick to point out that their proposed space-time crystal is not a perpetual motion machine because being at the lowest quantum energy state, there is no energy output. However, there are a great many scientific studies for which a space-time crystal would be invaluable. "The space-time crystal would be a many-body system in and of itself," Li says. "As such, it could provide us with a new way to explore classic many-body questions physics question. For example, how does a space-time crystal emerge? How does time translation symmetry break? What are the quasi-particles in space-time crystals? What are the effects of defects on space-time crystals? Studying such questions will significantly advance our understanding of nature." Peng Zhang, another co-author and member of Zhang's research group, notes that a space-time crystal might also be used to store and transfer quantum information across different rotational states in both space and time. Space-time crystals may also find analogues in other physical systems beyond trapped ions. "These analogs could open doors to fundamentally new technologies and devices for variety of applications," he says. Xiang Zhang believes that it might even be possible now to make a space-time crystal using their scheme and state of the art ion traps. He and his group are actively seeking collaborators with the proper ion-trapping facilities and expertise. "The main challenge will be to cool an ion ring to its ground state," Xiang Zhang says. "This can be overcome in the near future with the development of ion trap technologies. As there has never been a space-time crystal before, most of its properties will be unknown and we will have to study them. Such studies should deepen our understandings of phase transitions and symmetry breaking."

Read more at: http://phys.org/news/2012-09-clock-space-time-crystal.html#jCp
A space-time crystal, however, has only existed as a concept in the minds of theoretical scientists with no serious idea as to how to actually build one – until now. An international team of scientists led by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has proposed the experimental design of a space-time crystal based on an electric-field ion trap and the Coulomb repulsion of particles that carry the same electrical charge. "The electric field of the ion trap holds charged particles in place and Coulomb repulsion causes them to spontaneously form a spatial ring crystal," says Xiang Zhang, a faculty scientist with Berkeley Lab's Materials Sciences Division who led this research. "Under the application of a weak static magnetic field, this ring-shaped ion crystal will begin a rotation that will never stop. The persistent rotation of trapped ions produces temporal order, leading to the formation of a space-time crystal at the lowest quantum energy state." Because the space-time crystal is already at its lowest quantum energy state, its temporal order – or timekeeping – will theoretically persist even after the rest of our universe reaches entropy, thermodynamic equilibrium or "heat-death." Zhang, who holds the Ernest S. Kuh Endowed Chair Professor of Mechanical Engineering at the University of California (UC) Berkeley, where he also directs the Nano-scale Science and Engineering Center, is the corresponding author of a paper describing this work in Physical Review Letters (PRL). The paper is titled "Space-time crystals of trapped ions." Co-authoring this paper were Tongcang Li, Zhe-Xuan Gong, Zhang-Qi Yin, Haitao Quan, Xiaobo Yin, Peng Zhang and Luming Duan. The concept of a crystal that has discrete order in time was proposed earlier this year by Frank Wilczek, the Nobel-prize winning physicist at the Massachusetts Institute of Technology. While Wilczek mathematically proved that a time crystal can exist, how to physically realize such a time crystal was unclear. Zhang and his group, who have been working on issues with temporal order in a different system since September 2011, have come up with an experimental design to build a crystal that is discrete both in space and time – a space-time crystal. Papers on both of these proposals appear in the same issue of PRL (September 24, 2012). Ads by Google IIT JEE Syllabus - Video Lectures of Complete IIT JEE Syllabus By IITians. Order Free DVD - KaySonsEducation.co.in Traditional crystals are 3D solid structures made up of atoms or molecules bonded together in an orderly and repeating pattern. Common examples are ice, salt and snowflakes. Crystallization takes place when heat is removed from a molecular system until it reaches its lower energy state. At a certain point of lower energy, continuous spatial symmetry breaks down and the crystal assumes discrete symmetry, meaning that instead of the structure being the same in all directions, it is the same in only a few directions. "Great progress has been made over the last few decades in exploring the exciting physics of low-dimensional crystalline materials such as two-dimensional graphene, one-dimensional nanotubes, and zero-dimensional buckyballs," says Tongcang Li, lead author of the PRL paper and a post-doc in Zhang's research group. "The idea of creating a crystal with dimensions higher than that of conventional 3D crystals is an important conceptual breakthrough in physics and it is very exciting for us to be the first to devise a way to realize a space-time crystal." Just as a 3D crystal is configured at the lowest quantum energy state when continuous spatial symmetry is broken into discrete symmetry, so too is symmetry breaking expected to configure the temporal component of the space-time crystal. Under the scheme devised by Zhang and Li and their colleagues, a spatial ring of trapped ions in persistent rotation will periodically reproduce itself in time, forming a temporal analog of an ordinary spatial crystal. With a periodic structure in both space and time, the result is a space-time crystal. "While a space-time crystal looks like a perpetual motion machine and may seem implausible at first glance," Li says, "keep in mind that a superconductor or even a normal metal ring can support persistent electron currents in its quantum ground state under the right conditions. Of course, electrons in a metal lack spatial order and therefore can't be used to make a space-time crystal." Li is quick to point out that their proposed space-time crystal is not a perpetual motion machine because being at the lowest quantum energy state, there is no energy output. However, there are a great many scientific studies for which a space-time crystal would be invaluable. "The space-time crystal would be a many-body system in and of itself," Li says. "As such, it could provide us with a new way to explore classic many-body questions physics question. For example, how does a space-time crystal emerge? How does time translation symmetry break? What are the quasi-particles in space-time crystals? What are the effects of defects on space-time crystals? Studying such questions will significantly advance our understanding of nature." Peng Zhang, another co-author and member of Zhang's research group, notes that a space-time crystal might also be used to store and transfer quantum information across different rotational states in both space and time. Space-time crystals may also find analogues in other physical systems beyond trapped ions. "These analogs could open doors to fundamentally new technologies and devices for variety of applications," he says. Xiang Zhang believes that it might even be possible now to make a space-time crystal using their scheme and state of the art ion traps. He and his group are actively seeking collaborators with the proper ion-trapping facilities and expertise. "The main challenge will be to cool an ion ring to its ground state," Xiang Zhang says. "This can be overcome in the near future with the development of ion trap technologies. As there has never been a space-time crystal before, most of its properties will be unknown and we will have to study them. Such studies should deepen our understandings of phase transitions and symmetry breaking."

Read more at: http://phys.org/news/2012-09-clock-space-time-crystal.html#jCp

No comments:

Post a Comment